Category: AP State Important Questions

These AP 7th Class Science Important Questions 9th Lesson Heat, Temperature and Climate will help students prepare well for the exams.

AP Board 7th Class Science 9th Lesson Important Questions and Answers Heat, Temperature and Climate

Question 1.
What is heat?
Answer:
Heat is a form of energy which flows from hotter body (higher energy) to cooler body (lower energy).

Question 2.
How is heat measured?
Answer:
Heat is measured in Joules or calories with calorimeter.

Question 3.
What is temperature?
Answer:
The degree of hotness or coldness is called temperature.

Question 4.
How do we call the variations of hotness, coldness?
Answer:
The variations of hotness, coldness can be termed as degree of hotness and coldness.

Question 5.
What are the units of temperature?
Answer:
Temperature is measured in degrees of Celsius, degrees of Fahrenheit or Kelvin using a thermometer.

Question 6.
What is the SI unit of temperature?
Answer:
The SI unit of temperature is kelvin (K).

Question 7.
Write the different modes of transfer of heat?
Answer:

1. Conduction of heat
2. Convection of heat
3. Radiation of heat.

Question 8.
What is conduction?
Answer:
The process of transfer of heat from hotter to colder end through the conductor is called conduction.

Question 9.
What is convection of heat?
Answer:
The process of transfer of heat from source of heat to surface by the motion of par¬ticles is called “convection of heat”.

Question 10.
What is radiation of heat?
Answer:
The process of transfer of heat in the form of waves is called radiation.

Question 11.
What is thermal contact?
Answer:
The contact which transfers heat by any mode is called Thermal contact.

Question 12.
What is the condition for conduction of heat?
(OR)
When does conduction take place?
Answer:
Conduction takes place, only when the conductor is in touch (contact) with the source of heat. The contact which transfers heat by any mode is called Thermal contact. Conduction doesn’t take place without thermal contact.

Question 13.
What are called convectional currents?
Answer:
Heat is transferred by means of currents called convectional currents.

Question 14.
How does heat transfer in liquids and gases?
Answer:
In liquids and gases heat is transmitted by mode of convection of heat.

Question 15.
What is a medium?
Answer:
The material which helps in transfer of heat from one place to another is called a medium. Solid, liquid and gaseous substances act as medium for transfer of heat.

Question 16.
How does heat transfer if there is no medium?
Answer:
Heat transfer, in the form of waves from one place to another. It does not require any medium.

Question 17.
Write one application of radiation of heat.
(OR)
How does a thermal scanner work?
Answer:
The thermal scanner receives the heat in the form of radiation to measure our body temperature.

Question 18.
What happens if we heat and cool a metal?
Answer:
The metal expands on heating and contracts on cooling.

Question 19.
Which device is used to measure the temperature?
Answer:
Thermometers are used to measure temperature. .

Question 20.
Based on which principle a Thermometer does work?
Answer:
Thermometer works on the expansion of liquids (mercury).

Question 21.
Where the thermometers are used?
Answer:
People use thermometers in homes, hospitals, automobiles, industries and restaurants etc., to measure temperatures of different objects and substances.

Question 22.
Which is essential for our healthy living? (OR) Why should we protect environment?
Answer:
A clean environment is essential for heaithy living. So, we want a concrete plan to protect environment.

Question 23.
Why does alcohol use in thermometer? (OR)How can a alcohol thermometer mea-sures very low temperatures?
Answer:
The freezing point of alcohol is less than -100°C. So, it can be used to measure very low temperatures.

Question 24.
Write the different types of thermometers?
Answer:
The different types of thermometers are Clinical Thermometer, Laboratory Thermometer, Digital Thermometer and Six’s makimum and minimum thermometer.

Question 25.
Which instrument is used to measure the maximum (highest) and minimum (lowest) temperatures of a place in a day?
Answer:
Six’s maximum and minimum thermometer is one of the Meteorological Instruments used to measure maximum (highest) and minimum (lowest) temperatures of a place in a day.

Question 26.
What is the normal temperature of the human body?
Answer:
The normal temperature,of the human body is 37°C or 98.4°F.

Question 27.
Why does smoke and hot air move up?
Answer:
Smoke and hot air moves up because it expands and becomes lighter. . .

Question 28.
What is the use of ventilators in our house?
Answer:
Smoke and hot air moves up because it expands and becomes lighter through ventila¬tors and exhaust fans on the upper parts of the wall.

Question 29.
What happens to the air on heating?
Answer:
On heating, the air expands, occupying more space and becomes lighter.

Question 30.
What happens when air is compressed?
Answer:
The air pressure becomes more when air is compressed.

7th Class Science 9th Lesson Heat, Temperature and Climate Short Questions and Answers

Question 1.
When do we feel hot and cool?
Answer:

1. The heat when heat energy flows from hotter body to our body. We feel hot. Here we gain heat energy from the hotter body.
2. We feel cool, when heat energy flows from our body to colder body. Here, we lose heat energy.

Question 2.
How does heat flow? How do we determine its direction?
Answer:

1. Heat flows from a body of high temperature to a body of low temperature.
2. This direction is determined by temperature. ‘

Question 3.
How do we written degree of Celsius, degree of Fahrenheit and Kelvin?
Answer:

1. Degree Celsius: Celsius is written as °C and read as degree Celsius.
2. Degree Fahrenheit: Fahrenheit is written as °F and read as degree fahrenheit.
3. Kelvin is written as K and read as Kelvin.

Question 4.
What is Air pressure? How does it measure? What are the effects of the air pres-sure?
Answer:
Air pressure:
The force applied by air on any surface in contact is called “air pressure”.

Measuring of air pressure:
Air pressure is measured in height of mercury level in centimeters, and it is measured with a barometer. Now a days aneroid barometers are used to measure air pressure.

Effects of air pressure:
The air pressure becomes more when it is compressed. When air expands and rises up it creates low pressure, which drives the air high pressure from surrounding to move and occupy that place.

Question 5.
Why are cooking utensils made of metals while their handles are made of plastic or wood?
Answer:

1. Some materials allow heat through them, this property is called conductivity.
2. We use metals to make cooking vessels because they allow heat through them.
3. We use material which does not allow heat to pass through as handles.
4. So, cooking utensils made of metals while their handles are made of plastic or wood.

Question 6.
Write four applications of expansion of metals on heating.
Answer:

1. The electric power lines (wires) are held loose on poles
2. Rollers are kept under the beams of metal bridges
3. Mercury is used in thermometers
4. Small gaps are left between rails in railway tracks

Question 7.
Write the different modes of transfer of heat?
Answer:
Transfer of heat is in different types of materials. Heat gets transferred in three different modes, They are

1. Conduction of heat
2. Convection of heat
3. Radiation of heat

1) Conduction of heat:
This process of transfer of heat from hotter to colder end through the conductor is called conduction. This mode of transfer of heat happens more in solid conductors.

2) Convection of heat:
This process of transfer of heat from source of heat to surface by the motion of particles is called “convection of heat”. In liquids and gases heat is transmitted by mode of convection of heat.

3) Radiation of heat:
This process of transfer of heat in the form of waves is called radiation. Radiation does not need any material medium. Sun’s heat transfers to earth in the form of radiation.

Question 8.
Write the differences between good conductors and poor conductors?
Answer:

Good conductors	Poor conductors
1) The materials which allow heat to pass through them are called conductors of heat.	1) The materials which do not allow heat to pass through them easily are poor conductors of heat.
2) Example: Aluminum, iron and copper etc.	2) Example : Water, air, clothes, glass, cork, plastic, wood etc.
3) Heat can pass.	3) Heat cannot pass.
4) These are used to prepare cooking cooking vessels.	4) These are used to prepare handles of vessels.

Question 9.
How does a thermos flask work?
(OR)
Describe working of a thermos flask.
Answer:

1. Thermos flaSk has a two layered glass container and the air between these layers is removed to create vacuum.
2. The inner silver coating protects the contents (tea, coffee, milk) poured in the flask from losing heat through radiation.
3. As there is no medium between the walls of the flask. Neither conduction nor con-vection of heat takes place.
4. As a result, heat is not transferred outside the flask so it is retained inside the flask for a few hours.

Question 10.
What is the reason for in the expansion of rails, mercury in thermometer, air inside the puri etc?
Answer:

1. This is due to increase in the energy of particles present in these substances.
2. Particles of substances occupy more space when they get heated.
3. This is the reason for in the expansion of rails, mercury in thermometer, air inside the puri etc.

Question 11.
How does hot air balloon work?
Answer:

1. Warm air is lighter than cold air.
2. This property of air is used in flying of hot air balloons,
3. It contains a bag which is called as envelope, and it is filled with heated air.
4. There is a basket under the envelope which carries passengers and a source of heat.

Question 12.
Why mercury is used in thermometers?
Answer:
Mercury is used in thermometers, because it has the best properties to measure temperature.
Those are

1. It’s expansion is uniform.
2. It is bpaque and shining.
3. It does not stick to the sides of glass tube.
4. It is a good conductor of heat.
5. It has a high boiling point (357°C) and a low freezing point (-39°C). Hence a wide range of temperatures can be measured using a mercury.

Question 13.
Why alcohol is used in thermometers?
Answer:
Alcohol is used in thermometers, because it has the best properties to measure temperature. Those are

1. The freezing point of alcohol is less than -100°C.
2. So, it can be used to measure very low temperatures.
3. It’s expansion per degree Celsius rise in temperature is very large.
4. It can be colored brightly and hence is easily visible.

Question 14.
What are the melting point of ice and boiling point of water in different scales?
Answer:
1) Celsius scale :
Melting point of ice is 0°C and boiling point of water is 100°C

2) Fahrenheit scale :
Melting point of ice is 32°F and boiling point of water is 212°F

3) Kelvin scale :
Melting point bf ice is 273K and boiling point of water is 373K

Question 15.
Write the Formulas for temperature conversion 1) Celsius to Fahrenheit 2) Celsius to Kelvin.
Answer:

Question 16.
Explain two applications of transfer of heat.
Answer:
Thermal scanning:
The thermal scanner receives the heat in the form of radiation to measure our body temperature.

Thermos flask:
It has a two layered glass container and the air between these layers is removed to create vacuum. The inner silver coating protects the contents (tea, coffee, milk) poured in the flask from losing heat through radiation. As there is no medium between the walls of the flask. Neither conduction nor convection of heat takes place. As a result, heat is not transferred outside the flask so it is retained inside the flask for a few hours.

Question 17.
Fill in the table with suitable answers.

Answer:

Question 18.
What is the use of a Clinical Thermometer? How it convenient to record the reading?
Answer:

1. Clinical Thermometer is used in hospitals to measure the temperature of the human body.
2. It has a kink that prevents the mercury from flowing back into the bulb when it was taken out of the patient’s mouth.
3. This helps to record the temperature conveniently.

Question 19.
Where a Laboratory Thermometer is used? How it is better than the clinical ther-mometer?
(OR)
Describes laboratory Thermometer.
Answer:

1. Laboratory Thermometer is used in school labs, industries etc. to measure temperature. It has no kink.
2. It is made of a long stem and the bulb of mercury, so it can measure higher tempera-tures than clinical thermometer.

Question 20.
How does a Digital Thermometer work?
Answer:

1. Digital Thermometer works without Mercury.
2. It has a display which shows readings directly.
3. It is very easy to use it, we can use it by just pressing on/off button present on it.
4. Even children can also handle this one.

Question 21.
How do you use a clinical thermometer and a laboratory thermometer?
Answer:
Clinical thermometer

1. Wash the clinical thermometer properly with an antiseptic solution.
2. To lower the mercury level, hold the thermometer firmly and give some jerks.
3. Ensure that it falls below 35°C. Now place the bulb of the thermometer under your tongue.
4. After one or two minutes, take the thermometer out and note the reading.
5. This is your body temperature.
6. Don’t hold the thermometer by the bulb while reading it.

A Laboratory thermometer:

1. Take cold or hot water in a bowl. Place the mercury bulb of the thermometer in the water so that the bulb immerses in it.
2. Wait for some time till the mercury level shows a constant reading.
3. Note down that reading.

Question 22.
How does sunstroke occur?
(OR)
What happens when humidity increases in the air?
Answer:

1. Evaporation of sweat from our body makes us cool to maintain our body temperature.
2. In summer, the humidity of air is high. Due to high humidity and temperature, it becomes difficult to evaporate the sweat from our body to cool It down.
3. But still our body losses water.
4. High temperatures, along with humidity sometimes may cause heat stroke or sun¬stroke.

Question 23.
What is the first aid for sunstroke?
Answer:
First Aid for sunstroke :

1. Call 108 immediately. Move the victim to a cool ventilated place.
2. Then loosen his dress and remove extra clothing. Put a cold wet towel on his head, back of the neck, on the grain and under the armpits.
3. Fan air over the patient while wetting their skin with water from a sponge or wet cloth. Give plenty of cool, lightly salted water to drink often but in small sips.
4. Help the person stay calm without any anxiety.

Question 24.
What is weather of a place? What are its measuring components?
Answer:

1. The day-to-day variations in the components like temperature, humidity, rainfall, wind speed are called weather.
2. Maximum and minimum temperature of a day, air pressure, rainfall, wind speed and humidity are called measuring components of weather.

Question 25.
How do Meteorologists decide the climate of the place?
Answer:

1. Meteorologists (scientists who study and work on weather) record weather every day. .
2. These records of the weather have been preserved for the past several decades.
3. They help us to determine the weather pattern of a place.
4. The average weather pattern taken over a long period, say 25 years or more, is called the climate of the place.

Question 26.
Why does climate affect pur life style? What are its measuring components?
Answer:

1. Climate of a place remains unchanged for a long period of time. So, it affects our lifestyle.
2. The measuring components of climate are maximum and minimum temperature of a day, air pressure, rainfall, wind speed and humidity.

Question 27.
What are the differences between weather and climate?
Answer:

Weather	Climate
Weather keeps on changing rapidly.	Climate of a place remains unchanged for a long period of time.
It affects our daily life.	It affects our life style
Atmospheric conditions in a speciiic area and time.	Atmospheric conditions of a place for a long period of time.
It is not constant.	It remains constant for 25 years or more.

Question 28.
How weather and climate is effected our life?
Answer:

1. Daily weather and long-term climatic conditions influence the life style of humans and other living things directly and indirectly.
2. Some of them are diet, clothing, housing, occupations etc.

Question 29.
Doctor put the thermometer in the mouth of Karthikeya’s sister, Neha. By seeing this Karthikeya got some doubts and asked doctor. What could be those doubts?
Answer:

1. What is in the thermometer?
2. How does it show the temperature?
3. How can you say Neha got the fever?
4. How much time shall it place in the mouth?

Question 30.
Guess what will happen if we use the clinical thermometer to measure the temperature of the ice cubes or boiling water?
Answer:
We cannot measure too low and too high temperatures by using a clinical thermometer. It is made for clinical use only, so by using this we can measure from 35°C to 42°C only. If we measure temperature of boiling water or ice cubes it will break or it does not work.

Question 31.
Guess what will happen if a low air pressure is formed in your area?
Answer:
If a low air pressure is formed in our area, air blow from high air pressure area to occupy the low air pressure area. Sometimes this wind causes damage to roofs, trees etc.

Question 32.
Kalyan said that the climate was changed by being seen the dark clouds in the sky. Is the word climate correct in his statement?
Answer:
No. climate is different from weather. The changes occur during the period of some hours is called changing in weather. Climate is average weather conditions of a long period. So he had to use weather instead of climate in his statement.

Question 33.
What will happen, if there is no kink in the clinical thermometer?
Answer:
The kink prevents the mercury from flowing back into the bulb when it was taken out of the patient’s mouth. This helps to record the temperature conveniently. If there is no kink the level of the mercury will fall down in the gap of taking out from the patient and seeing the reading. So, it may show incorrect reading.

Question 34.
What is your observation in the activity of metal spoon with fixed pins and a candle and write the reason.
Answer:
I will observe the dropping of pins one after another from the flame end of the spoon. This is due to the transfer of heat from the end kept in the flame (hotter end) towards your hand (colder end) through a spoon (metal).

Question 35.
What are your observations in the activity of expansion of metal on heating?
Answer:
I will observe movement in the straw. The needle rolls on the second block of wood because of the expansion of the cycle spoke. If we remove the candles the needle rolls back causing movement in the straw opposite to the previous motion.

Question 36.
Read the graph and answer the following questions.

1. Which component was shown in the graph?
Answer:
Temperature

2. On which day the maximum temperatures recorded?
Answer:
On the dates, 1-12-2020 and 2-12-2020 the maximum temperature was recorded.

Question 37.
Take a glass and keep a postcard oh it. Wave your notebook above the post card to displace the air just above the postcard. What is your observation? What is the reason for it?
Answer:
The moving air creates low pressure. Hence the postcard lifts up due to the higher pressure on the card from air inside the glass.

Question 38.
Observe the figure and give answers to the following questions.
1. What mode of transfer of heat is observed in the spoon?
2. What is the source of heat?
3. What will happen after some time?
4. What is the medium here?

Answer:
1. Conduction of heat is observed in the spoon
2. Candle is the source of heat.
3. All the pins will fall down.
4. Metal in the spoon is the medium (solid)

Question 39.
Fill in the table with suitable answers.

Component in the weather	Units	Device to measure
Temperature	Kelvin or °C or °F
Air pressure	Mercury level in centimeters
	Millimeters	Rain gauge
Humidity	Grams per cubic meter.

Answer:

Component in the weather	Units	Device to measure
Temperature	Kelvin or C or °F	Thermometer
Air pressure	Mercury level in centimeters	Barometer
Rain fall	Millimeters	Rain gauge.
Humidity	Grams per cubic meter.	Hygrometer

Question 40.
Fill in the table with suitable answers.

Phenomenon	Examples
Convection	1) Milk 2)…………………. 3) …………………….
Conduction	1) Metal spoon 2)………. 3) ………………
Radiation	1) Sun to earth 2)………. 3) ……………….
Insulators	1) Rubber 2)…………….. 3) ………………
Conductors	1) Iron spoke 2)…………. 3) ………………

Answer:

Phenomenon	Examples
Convection	1) Milk 2) Eater 3)oil
Conduction	1) Metal spoon 2)copper vessel 3)nail
Radiation	1) Sun to earth 2) flask inner to outer 3) sun to moon
Insulators	1) Rubber 2) glass 3) water
Conductors	1) Iron spoke 2) vessels 3) copper wire

Question 41.
Draw the diagram of mercury laboratory thermometer.
Answer:

Question 42.
Draw the diagram of alcohol laboratory thermometer.
Answer:

Question 43.
Draw the diagram of a thermos flask and label its inner parts.
Answer:

44. Draw the diagram showing the arrangement of apparatus to show the expansion of liquids on heating?
Answer:

45. Draw the diagram of Six minimum and maximum temperatures and label the parts.
Answer:

7th Class Science 9th Lesson Heat, Temperature and Climate Long Questions and Answers

Question 1.
Compare different modes of transfer of heat.
Answer:

Conduction	Convection	Radiation
1) The process of transfer of heat from hotter to colder end through the conductor is called conduction of heat.	The process of transfer of heat from source of heat to surface by the motion of particles is called convection of heat.	The process of transfer of heat in the form of waves is called radiation.
2) In solids heat is transmitted by mode of conduction of heat.	In liquids and gases heat is transmitted by mode of convection of heat.	Radiation does not need any material medium
3) Ex: metals	Ex: water, milk	Ex : Sun’s heat to earth
4) No movement in the particles.	Movement in the particles.	No movement in the particles
5) It needs thermal contact.	It does not need thermal contact.	It does not need thermal contact.

Question 2.
Write about different types of thermometers.
Answer:
Clinical thermometer:

1. Wash the clinical thermometer properly with an antiseptic solution.
2. To lower the mercury level, hold the thermometer firmly and give some jerks.
3. Ensure that it falls below 35°C. Now place the bulb of the thermometer under your tongue.
4. After one or two minutes, take the thermometer out and note the reading.
5. This is your body temperature.
6. Don’t hold the thermometer by the bulb while reading it.

Laboratory thermometer:

1. Take cold or hot water in a bowl. Place the mercury bulb of the thermometer in the water so that the bulb immerses in it.
2. Wait for some time till the mercury level shows a constant reading.
3. Note down that reading.

Digital Thermometer:

1. It works without mercury.
2. It has a display which shows readings directly.
3. It is very easy to use it.
4. We can use it by just pressing on/off button present on it.
5. Even children can also handle this one.

Six’s maximum and minimum thermometer:

1. It is one of the Meteorological Instruments used to measure maximum (highest) and minimum (lowest) temperatures of a place in a day.
2. It has a cylindrical ‘Bulb A’, and ‘Bulb B’ connected through a ‘U-shaped tube’ con¬taining mercury.
3. Bulb A contains alcohol, and bulb B contains alcohol and its vapours.
4. When the temperature increases, the alcohol in the bulb A expands and pushes the mercury in the U tube, this makes indicator(M) to move up.
5. This indicates the maximum temperature of the day.
6. When the temperature decreases, alcohol in the bulb A contracts and pulls the mercury back.
7. This makes indicator (N) to move up.
8. This indicates the minimum temperature of the day.
9. After taking readings the indicators M and N are brought to their original places by using a magnet.

Question 3.
What is humidity? How does it measure? How does it affect or body? What is the first aid of sunstroke?
Answer:
HumidityAll the evaporated water from different water bodies go into air. This water vapour present in the air is called humidity.

Measurement of humidity:
Hygrometer is used to measure humidity in air and it is expressed in grams per cubic meter.

Effects of humidity:
Evaporation of sweat from our body makes us cool to maintain our body temperature. In summer, the humidity of air is high. Due to high humidity and temperature, it becomes difficult to evaporate the sweat from our body to cool it down. But, still our body losses water. High temperatures, along with humidity sometimes may cause heat stroke or sunstroke.

First Aid for sunstroke:
Call 108 immediately. Move the person out of the heat. Fan while spraying water to cool him. Let the person drink water to rehydrate.

Question 4.
Read the following table and answer the questions.

i) At what temperature, the ice melts? Express in Celsius.
ii) Which measurements are given in the table?
iii) Convert, 100°C into Fahrenheit and kelvin scale.
iv) What are the SI units of temperature?
Answer:
i) 0°C .
ii) Measurements of temperature are given.
iii) 100°C =212°F =373K
iv) Kelvin

Question 5.
How do you appreciate the weather reports?
Answer:

1. The day-to-day variations in the components like temperature, humidity, rainfall, , wind speed are called weather.
2. It keeps on changing and changes are very fast too.
3. One day it may be dry and sunny and the next day it may rain.
4. It gives the information about atmospheric conditions in a specific area and time.
5. We can get details of weather from weather reports and you can see these symbols on television, newspapers and in weather forecasting.
6. Weather forecasting is the application of science and technology to predict the conditions of the atmosphere using components of weather for a given location and time.
7. Weather reports are very useful to farmers, fishermen etc.
8. So I appreciate the weather reports.

Question 6.
How do you appreciate the properties of the mercury and alcohol as they are used in the thermometers?
Answer:
Properties of mercury:

1. Its expansion is uniform.
2. It is opaque and shining.
3. It does not stick to the sides of glass tube.
4. It is a good conductor of heat.
5. It has a high boiling point (357°C) and a low freezing point (-39°C).

Hence a wide range of temperatures can be measured using mercury.

Properties of alcohol:

1. The freezing point of alcohol is less than -100°C. So, it can be used to measure very low temperatures.
2. It’s expansion per degree Celsius rise in temperature is very large.
3. It can be coloured brightly and hence is easily visible.

Hence a wide range of temperatures can be measured using alcohol. Clinical ther-mometers, laboratory thermometers, six minimum and maximum thermometers etc. are made with alcohol or mercury or both.

Hence I appreciate the properties of the mercury and alcohol as they are used in the thermometers

AP Board 7th Class Science 9th Lesson 1 Mark Bits Questions and Answers Heat, Temperature and Climate

I. Multiple Choice Questions

Choose the correct answer and write its letters in the brackets.

1. It is a form of energy that flows from a hotter body to a cooler body.
A) Heat
B) Light
C) Sound
D) Electricity
Answer:
A) Heat

2. When heat energy flows from our body to Lassi. Here,
A) Lassi loss Heat energy
B) Body lose heat energy
C) Body gain heat energy
D) A and C
Answer:
B) Body lose heat energy

3. Joules are units of
A) Humidity
B) Climate
C) Heat
D) Air pressure
Answer:
C) Heat

4. The degree of hotness or coldness is called ………..
A) Humidity
B) Temperature
C) Heat
D) Air pressure
Answer:
D) Air pressure

5. Temperature is measured in…….
A) Degrees of Celsius
B) Degrees of Fahrenheit
C) Kelvin
D) All
Answer:
D) All

6. The SI unit of temperature is ………….
A) Degrees of Celsius
B) Degrees of Fahrenheit
C) Kelvin
D) All
Answer:
C) Kelvin

7. Kelvin is written as
A) °C
B) °F
C) °K
D) K
Answer:
D) K

8. Which is correct?
i) Heat is the degrees of hotness or coldness.
ii) Heat is measured in joules
A) i only
B) ii only
C) both i & ii
D) both are incorrect
Answer:
B) ii only

9. Cooking utensils are made of ………..
A) conductors
B) insulators
C) fuels
D) none of the above
Answer:
A) conductors

10. Handles of cooking vessels are made of …………….
A) conductors
B) insulators
C) fuels
D) none of the above
Answer:
B) insulators

11. A: Metals are used to make cooking vessels.
R: Metals allow heat through them.
Which is correct?
A) A & R are correct and R supports A
B) A & R are correct but R does not support A
C) A is correct but R is wrong
D) R is Correct but A is wrong
Answer:
A) A & R are correct and R supports A

12. The ability of a material to conduct heat is called …………..
A) Thermal conductivity
B) Thermal resistivity
C) Thermometer
D) None
Answer:
A) Thermal conductivity

13. It is not a good conductor.
A) Copper
B) Steel
C) Plastic
D) Cast iron
Answer:
C) Plastic

14. Insulator is….
A) Water
B) Glass
C) Plastic
D) All
Answer:
D) All

15. Heat cannot pass in the mode of
A) Conduction
B) Convection of heat
C) Radiation of heat
D) None
Answer:
D) None

16. In which heat is transferred from one end to another end by the mode of conduction.
A) Steel spoon
B) Water
C) A and B
D) Sun to earth
Answer:
A) Steel spoon

17. This mode of transfer of heat happens more in solid conductors
A) Conduction
B) Convection of heat
C) Radiation of heat
D) None
Answer:
A) Conduction

18. This process of transfer of heat from source of heat to surface by the motion of particles
A) Conduction
B) Convection of heat
C) Radiation of heat
D) all
Answer:
B) Convection of heat

19. This is not a medium of heat energy.
A) Solid
B) Liquid
C) Gas
D) None
Answer:
D) None

20. This mode of transfer of heat doesn’t require any media.
A) Conduction
B) Convection of heat
C) Radiation of heat
D) All
Answer:
C) Radiation of heat

21. The process of transfer of heat in the form of waves is called
A) Conduction
B) Convection of heat
C) Radiation of heat
D) All
Answer:
C) Radiation of heat

22. Which instrument can control the transfer of heat (loss of heat)?
A) Thermos flask
B) Thermometer
C) Thermal scanner
D) All
Answer:
A) Thermos flask

23. The flask retains hot inside the flask for
A) a few hours
B) ever
C) never
D) a few weeks.
Answer:
A) a few hours

24. Thermos flask was invented by
A) Sir James cook
B) Sir James Chadwick
C) Sir James Dewar
D) Sir James watts
Answer:
C) Sir James Dewar

25. Which of the following expands on heating and contracts on cooling?
A) Solid
B) Liquid
C) Gas
D) All
Answer:
D) All

26. Air on cooling
A) contracts
B) occupy less space.
C) expand
D) A and B
Answer:
D) A and B

27. Warm air is lighten than cold air. This property of air is used in
A) hot air balloons
B) kites
C) rockets
D) all
Answer:
A) hot air balloons

28. Thermometer contains bulb of
A) mercury
B) alcohol
C) A or B
D) silver
Answer:
C) A or B

29. Mercury is a in room temperature.
A) solid
B) liquid
C) gas
D) all
Answer:
A) solid

30. This is not a property of the mercury .
A) Its expansion is uniform.
B) It is a good conductor of heat.
C) It easily sticks to the sides of glass tube.
D) It has a high boiling point.
Answer:
C) It easily sticks to the sides of glass tube.

31. The boiling point and a freezing point of the mercury are
A) -39°C and 357°C
B) 357°C and-39°C
C)100°C and 0°C
D) none
Answer:
B) 357°C and-39°C

32. A: The freezing point of alcohol is more than -100°C.
R: Alcohol can be used to measure very low temperatures.
A) A & R are correct and R supports A
B) A & R are correct but R does not support A
C) A is correct but R is wrong
D) R is correct but A is wrong
Answer:
D) R is correct but A is wrong

33. Number of divisions in Fahrenheit scale is
A) 100
B) 212
C) 180
D) 32
Answer:
C) 180

34. Number of divisions in Kelvin scale is
A) 100
B) 212
C) 180
D) 32
Answer:
A) 100

35. Number of divisions in Celsius scale is
A) 100
B) 212
C) 180
D) 32
Answer:
A) 100

36. Which prevents the mercury from flowing back into the bulb in clinical thermometer.
A) Capillary
B) Kink
C) Bulb
D) Magnet
Answer:
B) Kink

37. Laboratory thermometer can measure higher temperatures than clinical thermometer because, it has
A) long bulb
B) long stem
C) short bulb
D) short stem
Answer:
B) long stem

38. This thermometer can work without Mercury.
A) Six max and min thermometer
B) Digital Thermometer
C) Clinical thermometer
D)All
Answer:
B) Digital Thermometer

39. Who invented Six’s maximum and minimum thermometer in 1780?
A) Sir James cook
B) James watt
C) Sir James Dewar
D) James Six
Answer:
D) James Six

40. The correct order is
i) After one or two minutes, take the thermometer out and note the reading,
ii) Place the bulb of the thermometer under your friend’s tongue.
iii) Wash the clinical thermometer properly with an antiseptic solution.
iv) To lower the mercury level, hold the thermometer firmly and give some jerks.
A) iv, ii, i, iii
B) iv, iii, ii, i
C) iii, iv, ii, i
D) ii, iii, iv, i
Answer:
C) iii, iv, ii, i

41. The normal temperature of the human body is
A) 37°C
B) 98.4°F
C) 310K
D) all
Answer:
D) all

42. Ventilators are working on
A) Air expands on heating
B) Air contracts on heating
C) Metal expands on heating
D) Air contracts on cooling
Answer:
A) Air expands on heating

43. Which is used to measure the air pressure?
A) Hygrometer
B) Thermometer
C) Barometer
D) Rain gauge
Answer:
C) Barometer

44. A: If roofs were weak, they could be lifted and blown away.
R: The moving air creates high pressure.
A) A & R are correct and R supports A
B) A & R are correct but R does not support A
C) A is correct but R is wrong
D) R is correct but A is wrong
Answer:
C) A is correct but R is wrong

45. Rain fall is measured with a
A) hygrometer
B) thermometer
C) barometer
D) rain gauge
Answer:
D) rain gauge

46. This is not a measuring component of weather
A) humidity
B) temperature
C) wind speed
D) none
Answer:
D) none

47. Humidity is measured in
A) g/cubic meter
B) mm/cubic meter
C) °C
D) m/°C
Answer:
A) g/cubic meter

48. In summer, the humidity of air is
A) low
B) high
C) no change
D) zero
Answer:
B) high

49. High temperatures, along with humidity sometimes may cause
A) kwashiorkor
B) beriberi
C) corona
D) sunstroke
Answer:
D) sunstroke

50. It gives the information about atmospheric conditions in a specific area and time.
A) Weather
B) Climate
C) A and B
D) None
Answer:
A) Weather

51. This deals with a long period.
A) Weather
B) Climate
C) A and B
D) None
Answer:
B) Climate

52. It affects our lifestyle
A) Weather
B) Climate
C) A and B
D) None
Answer:
B) Climate

53. Which phenomenon measures atmospheric conditions in a specific area and time?
A) Weather
B) Climate
C) A and B
D) None
Answer:
A) Weather

II. Fill in the blanks

1. Heat is a form of energy that flows from a ………………. body to a ………………. body.
2. Heat is measured in ………………. with calorimeter
3. Heat flows from a body of high temperature to a body of low temperature. This direction is determined by ………………. .
4. The degree of ………………. is called ‘temperature’.
5. Degree of Celsius is written as ………………. .
6. Degree of Fahrenheit is written as ………………. .
7. Some materials allow heat through them, this property is called ………………. .
8. Water, air, clothes, glass, cork, plastic, wood etc. are some examples of ………………. .
9. This process of transfer of heat from hotter to colder end through the conductor’ is called ………………. .
10. The contact which transfers heat by any mode is called ………………. .
11. Water is a ………………. of heat.
12. Heat is transferred by means of ………………. called convectional currents.
13. The materials which help in transfer of heat from one place to another are called ………………. .
14. Sun’s heat transfers to earth in the form of ………………. .
15. The thermal scanner receives the heat in the form of ………………. to measure our body temperature.
16. The inner ………………. in thermos flask protects the contents (tea, coffee, milk) poured in the flask from losing heat through radiation.
17. As there is ………………. between the walls of the flask; neither conduction nor convection of heat takes place.
18. Particles of substances occupies ………………. space when they get heated.
19. Small gaps left between rails in railway tracks, because metal ………………. on heat
20. ………………. are used to measure temperature.
21. The principle involved in working of a thermometer is ………………. .
22. The melting point of ice is ………………. °C
23. The melting point of ice and boiling point of water in Fahrenheit are ………………. .
24. The melting point of ice and boiling point of water in SI units are ………………. .
25. The formula to convert Celsius to Kelvin is ………………. .
26. The formula to convert Celsius to Fahrenheit is ………………. .
27. ………………. is used in hospitals to measure the temperature of the human body.
28. Clinical Thermometer has a ………………. that prevents the mercury from flowing back into the bulb when it was taken out of the patient’s mouth.
29. After taking readings in six max and min thermometer the indicators I₂ and I₁ are brought to their original places by using ………………. .
30. The normal temperature of the human body is ………………. .
31. Smoke and hot air moves up because it ………………. on heating and becomes lighter.
32. The force applied by air oh any surface in contact is called ………………. .
33. The air pressure becomes ………………. when it is compressed.
34. When air expands and raises up it creates ………………. .
35. ………………. drives the air high pressure from surrounding to move and occupy that place.
36. Air pressure is measured in height of ………………. level in centimeters
37. ………………. is measured in millimeters by using a rain gauge.
38. The water vapour present in the air is called ………………. .
39. ………………. is used to measure humidity in air and it is expressed in grams per cubic meter.
40. Evaporation of ………………. from our body makes us cool to maintain our body temperature.
41. The day-to-day variations in the components like temperature, humidity, rainfall, wind speed are called ………………. .
42. ………………. forecasting is the application of science and technology to predict the conditions of the atmosphere using components of weather for a given location and time.
43. It is easier to know about weather with the help of ………………. than tables.
44. ………………. study and work on weather and record weather every day.
45. The average weather pattern taken over a long period, say 25 years or more, is called the ………………. of the place.
46. Expansion of IMD is ………………. .
47. The abnormal variation in the components of climate is called ………………. .
Answer:

1. hotter, cooler
2. Joules or calories
3. temperature
4. hotness or coldness
5. °C
6. °F
7. conductivity
8. insulators
9. conduction
10. Thermal contact
11. poor conductor
12. currents
13. medium
14. radiation
15. radiation
16. silver coating
17. no medium or vacuum
18. more
19. expand
20. Thermometers
21. expansion of liquids on heating
22. 0
23. 32°F, 212°F
24. 273K, 373K
25. K °C + 273
26. 
27. Clinical Thermometer
28. kink
29. a magnet
30. 37°C or 98.4°F
31. expands
32. air pressure
33. more
34. low pressure
35. Low pressure
36. mercury
37. Rainfall
38. Humidity
39. Hygrometer
40. Sweat
41. weather
42. Weather
43. graphs
44. Meteorologists
45. Climate
46. Indian Meteorological Department
47. climate change

III. Match the following

1.

Group – A	Group – B
1) heat	a) cm of mercury level
2) temperature	b) Kelvin
3) air pressure	c) mm
4) rain fall	d) Joule

Answer:

Group – A	Group – B
1) heat	d) Joule
2) temperature	b) Kelvin
3) air pressure	a) cm of mercury level
4) rain fall	c) mm

2.

Group – A	Group – B
1) humidity	a) barometer
2) temperature	b) hygrometer
3) air pressure	c) rain gauge
4) rainfall	d) thermometer

Answer:

Group – A	Group – B
1) humidity	b) hygrometer
2) temperature	d) thermometer
3) air pressure	a) barometer
4) rainfall	c) rain gauge

3.

Group – A	Group – B
1) water	a) radiation
2) heat	b) convection
3) metal	c) expansion
4) vacuum	d) conduction

Answer:

Group – A	Group – B
1) water	b) convection
2) heat	c) expansion
3) metal	d) conduction
4) vacuum	a) radiation

4.

Group – A	Group – B
1) nail	a) clinical thermometer
2) cloth	b) lab thermometer
3) mercury	c) conductor
4) alcohol	d) insulator

Answer:

Group – A	Group – B
1) nail	c) conductor
2) cloth	d) insulator
3) mercury	a) clinical thermometer
4) alcohol	b) lab thermometer

5.

Group – A	Group – B
1) weather	a) low pressure
2) climate	b) long period
3) wind	c) water vapour
4) humidity	d) rapid change

Answer:

Group – A	Group – B
1) weather	d) rapid change
2) climate	b) long period
3) wind	a) low pressure
4) humidity	c) water vapour

6.

Group – A	Group – B
1) gas expansion	a) alcohol thermometer
2) liquid expansion	b) parachute
3) solid expansion	c) railway rails
4) gas contraction	d) LPG cylinder

Answer:

Group – A	Group – B
1) gas expansion	b) parachute
2) liquid expansion	a) alcohol thermometer
3) solid expansion	c) railway rails
4) gas contraction	d) LPG cylinder

7.

Group – A	Group – B
1) Kelvin	a) °F
2) Fahrenheit	b) K
3) Celsius	c) J
4) Heat	d) °c

Answer:

Group – A	Group – B
1) Kelvin	b) K
2) Fahrenheit	a) °F
3) Celsius	d) °c
4) Heat	c) J

Do You Know?

→ Heat is measured In Joules or Calories with calorimeter.

→ Warm air is lighter than cold air. This property of air is used in flying of hot air balloons. It contains a bag which is called as envelope, and it is filled with heated air. There is a basket under the envelope which carries passengers and a source of heat.

→ Formulas for temperature conversion

1) Celsius to Fahrenheit
2) Celsius to Kelvin C=K – 273

→ Now a days cameras have been developed to detect heat. Those are called thermal- cameras.

→ The Indian Meteorological Department (IMD) studies climate of our country. 23rd March is celebrated as World Meteorological Day.

These AP 7th Class Science Important Questions 8th Lesson Wonders of Light will help students prepare well for the exams.

AP Board 7th Class Science 8th Lesson Important Questions and Answers Wonders of Light

Question 1.
What is source of light? Give examples.
Answer:
Light comes from different objects called sources, of light. Ex: Sun, candle, tube light.

Question 2.
What are Parallel beam of light rays?
Answer:
Light rays which travel parallel to each other are called Parallel beam of light rays.

Question 3.
What are converging beam of light, rays?
Answer:
Light rays which travel from different directions to meet at a point are called as con¬verging beam of light rays.

Question 4.
What is reflection of light?
Answer:
The process of bouncing back of light rays into the same medium after falling on a smooth or rough surface from the light source is called “reflection of light”.

Question 5.
How objects are visible?
Answer:
Objects are visible only when light falls on the objects and bounces back to the eye.

Question 6.
What is angle of incidence?
Answer:
The angle made by incident ray with the normal is called angle of incidence (i).

Question7.
What is angle of reflection?
Answer:
The angle made by the reflected ray with the normal is called the angle of reflection (r).

Question 8.
Write the first law of reflection.
Answer:
The angle of incidence is always equal to angle of reflection.
Angle of incidence = Angle of reflection
This is the first law of reflection.

Question 9.
Write the second law of reflection.
Answer:
The incident ray reflected ray and normal to the surface are present in the same plane and incident, reflected rays are on either side of normal. This is the second law of reflection.

Question 10.
How is the object distance and image distance of a plane mirror?
Answer:
The distance of the object from the mirror is equal to the distance of image from the mirror.

Question 11.
What is object distance?
Answer:
The distance of the object from the mirror is called object distance.

Question 12.
What is image distance?
Answer:
The distance of the image from the mirror is called image distance.

Question 13.
We are able to see our image in the mirror. Can we get pur image on screen?
Answer:
We cannot get the image formed by a plane mirror on the screen.

Question 14.
What is a real image?
Answer:
The image which can get on a screen is called real image.

Question 15.
What is a virtual image?
A. The image which cannot get it on screen is called virtual image.

Question 16.
How is the nature of the image formed by a plane mirror?
Answer:
The nature of the image formed by a plane mirror is virtual and erect image.

Question 17.
What is Periscope?
Answer:
Periscope is an instrument used in submarines to see the objects or persons above the water level.

Question 18.
What is the use of a Periscope?
Answer:
We can use this to see the objects outside the room through the window while hiding ourself in the room.

Question 19.
What is a convex mirror?
Answer:
The spherical mirror which has reflecting surface bent outward is called convex mirror.

Question 20.
What is a concave mirror?
Answer:
The spherical mirror which has reflecting surface bent inward is called concave mirror.

Question 21.
What is a lens?
Answer:
A piece of glass or any other transparent material with curved sides is called a lens.

Question 22.
What is a convex lens?
Answer:
Lens which is thick in center and thin at the edges is called convex lens.

Question 23.
What is a concave lens?
Answer:
Lens which is thin in the Centre and thick at the edges is called concave lens.

Question 24.
What basic principle is involved in a periscope?
Answer:
Periscope is prepared based on the principle of reflection of light from plane mirrors.

Question 25.
What are the uses of a concave mirror?
Answer:
Concave mirrors are used by dentists, ophthalmologists, ENT doctors and also in head lights of vehicles.

Question 26.
What are the uses of a convex mirror?
Answer:
Convex mirrors are used as rearview mirrors in vehicles and safety mirrors at curved roads.

Question 27.
How white light is composed?
Answer:
White light is composed of seven colours.

Question 28.
Why do dentists use a concave mirror?
Answer:
Dentists also use concave mirrors to get a bigger image of the teeth.

7th Class Science 8th Lesson Wonders of Light Short Questions and Answers

Question 1.
What is a beam of light? How many types of beam of lights are there?
Answer:
The bundle of light rays are called beam of light rays. These are three types.

1. Parallel beam of light rays
2. Converging beam of light rays
3. Diverging beam of light rays.

Question 2.
Write the differences between natural and artificial light sources.
Answer:

Natural sources of light	Artificial sources of light
1. Objects that emit light on their own are known as natural sources of light.	1. Objects that release light artificially are called man made sources of light or artificial sources of light.
2. Sources like sun, stars are natural sources of light.	2. Sources like bulb, torch light, candle artificial sources of light.
3. These emit light on their own.	3. These don’t emit light on their own.

Question 3.
What is a ray of light? How does it represent?
Answer:

1. The direction or path along which light travels is called a ray of light.
2. It is denoted by a straight line with an arrow mark.
3. The straight line indicates the path of light and arrow mark indicates the direction of light from the source.

Question 4.
Differentiate between regular and irregular reflections.
Answer:

Regular reflection	Irregular reflection
1. Reflection from a smooth and shiny surface is called regular reflection.	1. Reflection from an irregular or uneven surface is called irregular reflection or diffused reflection.
2. Clear images are formed in case of regular reflection.	2. Images are not clear or sometimes cannot form the images at all in case of irregular reflection.
3. Plane mirrors, stable water surfaces, polished metals and stones can give regular reflections.	3. Rough surfaces, unstable water surfaces, unpolished metals and stones can give irrregular reflections.

Question 5.
What are the characteristics of image by plane mirror?
Answer:
Characteristics of image by plane mirror:

1. Object distance is equal to image distance.
2. Size of the object is equal to size of the image.
3. The image formed is always virtual and erect.
4. Laterally inverted image is formed, (left and right alternates)

Question 6.
When you are eating food with right hand it appears to be eating with left hand in a mirror. Why?
Answer:
When you are eating food with right hand it appears to be eating with left hand in a mirror. Such a shift of lateral side of images in opposite direction is called lateral inversion. Images formed by plane mirrors undergo lateral inversion.

Question 7.
Write the differences between real and virtual images.
Answer:

Real images	Virtual images
1. The image which can get on a screen is called real image.	1. The image which cannot get it on screen is called virtual image.
2. Real image is always inverted.	2. Virtual image is always erected.
3. Concave mirrors form real images.	3. Plane mirrors form virtual images.
4. We cannot see directly in the mirror.	4. We can see directly in the mirror.

Question 8.
Find the number of images will be formed, if the two mirrors are kept at an angle 50° between them?
Answer:
If the two mirrors are kept at an angle 50s between them, then the number of images between them are,

Seven is the next integer after 6.2.
So, the number of images formed will be seven

Question 9.
Write the differences between a convex mirror and a concave mirror.
Answer:

Convex mirror	Concave mirror
1. The spherical mirror which has Reflecting surface bent outward is called convex mirror.	1. The spherical mirror which has Reflecting surface bent inward is called concave mirror.
2. The light is diverged by the convex mirror.	2. The light is converged by the concave mirror.
3. It is used in vehicles as rear view mirrors.	3. It is used by dentists and ophthal-mologists.
4. A convex mirror always forms virtual, erect, smaller image irrespective of the position of the object.	4. A concave mirror forms real and virtual images, erect and inverted images smaller, same size and bigger images depending on the position of object in front of it.

Question 10.
Write the characteristics of image formed by a concave mirror and a convex mirror.
Answer:
1) Characteristics of image formed by a concave mirror :
A concave mirror forms real and virtual images, erect and inverted images, smaller, same size and bigger images depending on the position of object infront of it.

2) Characteristics of image formed by a convex mirror :
A convex mirror always forms virtual, erect, smaller image irrespective of the position of the object.

Question 11.
How the ENT doctors are using a concave mirror?
Answer:

1. Concave mirrors are used by ENT doctors as Head mirrors.
2. They have this mirror strapped on their head.
3. Light from the bulb is made to fall on the mirror gets reflect from it.
4. This reflected light is focused into the throat or ear of the patient. So that the doctor can examine inner parts clearly.

Question 12.
How the ophthalmologists are using a concave mirror?
Answer:

1. Ophthalmologists use a special instrument called Ophthalmoscope.
2. It is fitted with a.concave mirror having a small hole near its center.
3. The concave mirror helps the doctor to direct a beam of light into the patient’s eye and see his/her retina clearly through the hole in the mirror.

Question 13.
Why the surface of reflection in a torch light or a headlight of vehicle is made with a concave mirror, behind the bulb?
Answer:

1. The surface of reflection in a torch light or a headlight of vehicle is made with a concave mirror, behind the bulb.
2. Light released from the bulb falls on the concave surface.
3. After reflection from concave surface, all the light rays travel parallel to each other.
4. So that we can observe focused light at a distance.

Question 14.
Why do convex mirrors use beside the drivers in vehicles?
Answer:

1. The convex mirrors which are used beside the drivers in vehicles are called rear view mirrors. .
2. These mirrors form images of objects spread over a large area.
3. So, these help the driver to see the traffic behind them.

Question 15.
Write the uses of convex mirrors.
Answer:

1. Large convex mirrors kept at the corners of curved roads to avoid accidents.
2. Convex mirrors form images of vehicles on both sides of curved road.
3. These mirrors are also used at the junctions of roads.
4. These mirrors used as rear view mirrors in vehicles.

Question 16.
Which colour of light is better to see? Why?
Answer:

1. Yellow light is better to see.
2. Yellow light has been proven effective in protecting retina than blue light which causes damage to retina.

Question 17.
What is the rule of 20 – 20 – 20?
Answer:
While watching TV or computer a simple rule 20 – 20 – 20 helps us in protecting eyesight. After 20 minutes of watching TV or computer screen, take 20 seconds break and watch the TV or computer around 20 feet away.

Question 18.
Akshaya got many doubts while her brother is burning a paper with a magnifier. What would be those doubts?
Answer:

1. How does a magnifier burn the paper?
2. Why are the sun rays passing through the magnifier, without reflecting back?
3. What is the shape of the magnifier?
4. What happens to the sun rays after passing through the magnifier?

Question 19.
Guess, what will happen if a concave mirror or a plane mirror is used as a rear view mirror?
Answer:

1. Generally convex mirror is used in rear view mirror.
2. Because these mirrors form images of objects spread over a large area.
3. The images’formed by the convex mirror have the characteristics like erect, virtual and smaller images.
4. So, these help the driver to see the traffic behind them.
5. If we U9e a concave mirror instead of a convex mirror it does not form any images of the rear objects.
6. If we use a plane mirror instead of a convex mirror we cannot see the images of the rear objects totally.

Question 20.
Ramesh is not able to identify different spherical mirrors. Explain him, the differ-ences between concave and convex mirrors by asking some questions.
Answer:

1. How the shining surface of the mirrors are bent?
2. What do we call the mirror, if it has reflecting surface bent inwards?
3. What do we call the mirror, if it has reflecting surface bent outwards?
4. How is your image in the both the mirrors?
5. Which mirror forms smaller image?
6. Which mirror can form your image on the wall?

Question 21.
Guess, why does we cannot see our face on a wall clearly?
Answer:
Light rays coming from the face fall on the wall and suffer irregular reflection, because wall has rough surface. Irregular reflection causes formation of no image on the wall or sometimes not cleared images.

Question 22.
How do you show the parallel light by an activity?
Answer:

1. Take a plank and cardboard.
2. Make small slits on cardboard.
3. Keep the cardboard on the plank perpendicular to it. Keep it in sunlight during afternoon.
4. The light rays from the sun fall on the cardboard and passed through the slits. We can observe that the light rays are travelling parallel to each other.

Question 23.
How do make your own spherical mirrors?
Answer:

1. Take a silver paper used for decoration.
2. Paste the silver paper without folds on a postcard size chart paper.
3. Allow it to dry by keeping it under some heavy books.
4. Bend the sheet slightly forward as its shiny surface comes inwards.
5. It works as a concave mirror.
6. Now bend the sheet slightly backward as its shiny surface comes out wards.
7. It works as a convex mirror.

Question 24.
Fill in the table with suitable answer.

Answer:

Question 25.
How do you appreciate the role of the spherical mirrors in our daily life?
Answer:

1. Concave and convex mirrors are spherical mirrors.
2. Concave mirrors are used by dentists, ophthalmologists, ENT doctors and also in head lights of vehicles.
3. Convex mirrors are used as rear view mirrors in vehicles and safety mirrors at curved roads.
4. Hence, I appreciate the role of the spherical mirrors in our daily life.

Question 26.
What precautions do you take to watch a TV?
Answer:
While watching TV or computer a simple rule 20 – 20 – 20 helps us in protecting eyesight. After 20 minutes of watching TV or computer screen, take 20 seconds break and watch the TV or computer around 20 feet away.

Question 27.
Draw the diagrams of regular reflection and diffused reflection.
Answer:

Question 28.
Draw the diagram of a source of light.
Answer:

Question 29.
Draw the diagram showing the reflection of an incident ray.
(OR)
Draw the diagram showing an incident ray, reflected ray and a normal.
Answer:

Question 30.
Draw the diagram of a periscope and lable its inner parts.
Answer:

Question 31.
Draw the diagram of a convex mirror and concave mirror.
Answer:

Question 32.
Draw the diagram of a light ray.
Answer:

Question 33.
Draw the diagrams of a convex lens and a concave lens.
Answer:

Question 34.
Draw the diagram of arrangement of the apparatus in the activity of verifi¬cation of the laws of reflection.
Answer:

7th Class Science 8th Lesson Wonders of Light Long Questions and Answers

Question 1.
a) What is reflection of light?
b) How many types of reflection are there? What are they?
c) Write the laws of reflection.
Answer:
a) The process of bouncing back of light rays into the same medium after falling on a smooth or rough surface from the light source is called “reflection of light”.

b) Reflections are of two types :
1. Regular reflection
2. Diffused reflection.

Reflection from a smooth and shiny surface is called regular reflection. Reflection from an irregular or uneven surface is called irregular reflection or diffused reflection.

c) Laws of reflection :
There are two laws of reflection.
1. Angle of incidence is equal to angle of reflection.
2. The incident ray reflected ray and normal to the surface are present in the same plane. Incident and reflected rays are on either side of normal.

Question 2.
Draw the reflected ray to the given incident ray.

Answer:

Question 3.
Answer the following.
1) What is light?
2) What is source of light?
3) How do you classify the light sources?
4) What are the different types of light beams? Explain.
Answer:
1) Light is a form of energy.

2) Light energy releases from different objects called sources of light.

3) Sources which release light energy on their own are called natural sources.
Ex: sun, stars.
Sources which need the human involvement to release light energy are called manmade sources of light.
Ex: torch light, candle, bulb etc.

4) Actually, light is not a single ray, but a bundle of rays. This bundle of light rays are called beam of light rays. These are three types :

i. Parallel beam of light rays :
Light rays which travel parallel to each other are called Parallel beam of light rays.

ii. Converging beam of light rays :
“Light rays which travel from different directions to meet at a point are called as Converging beam of light rays”.

iii. Diverging beam of light rays :
“Light rays which travel from a source moving in different’ directions are called as Diverging beam of light rays.”

Question 4.
What precautions do you take while watching TV or modern gadgets? Why?
Answer:

1. Light plays an important role in the sensation of vision.
2. Now a day’s people, due to the usage of modern gadgets, like mobile phone, com-puters, televisions through which light enters the eyes.
3. Watching TV too much or sitting very close to it may make your eyes-tired cause dryness of eyes and gradually lead to headache.
4. While using computer or TV ensures that your room is well lighted.
5. While watching TV or computer a simple rule 20 – 20 – 20 helps us in protecting eyesight.
6. After 20 minutes of watching TV or computer screen, take 20 seconds break and watch the TV or computer around 20 feet away.
7. Reduce blue light in cell phones and computers are switched on power saving mode during night.
8. Yellow light has been proven effective in protecting retina than blue light which causes damage to retina.

Question 5.
How do you appreciate the role of the reflection of light in our daily life?
Answer:

1. The process of bouncing back of light rays into the same medium after falling on a smooth or rough surface from the light source is called “reflection of light”.
2. When light falls on an object it reflects back. Reflected ray when reaches to our eyes, causes sensation of vision.
3. If there is no phenomenon of reflection, we cannot see the colourful world.
4. Periscope is prepared based, on the principle of reflection of light from plane mirrors.
5. Kaleidoscope is prepared based on the principle of multiple reflection of light from plane mirrors.
6. The dentists, ophthalmologists, ENT doctors etc. give us treatment by using reflection of light through the concave mirrors.
7. The drivers of the vehicles observe the rear objects of his vehicles by using reflection of light through the convex mirrors.
8. Hence, I appreciate the role of the reflection of light in our daily life.

AP Board 7th Class Science 8th Lesson 1 Mark Bits Questions and Answers Wonders of Light

I. Multiple Choice Questions

Choose the correct answer and write its letters in the brackets.

1. This is not a natural sources of light.
A) sun
B) stars
C) moon
D) none
Answer:
C) moon

2. Example to human involvement is needed to release light
A) sun
B) stars
C) candle
D) none
Answer:
C) candle

3. Light rays which travel from a source moving in different directions are called as of light rays.
A) parallel
B) converge
C) diverge
D) B and C
Answer:
C) diverge

4. Which of the following does not give regular reflection?
A) mirror
B) cloth
C) new steel plate
D) polished marble
Answer:
B) cloth

5. In case of irregular reflection images cure
A) not clear
B) cannot form
C) clear
D) A & B
Answer:
D) A & B

6. These are in the same plane.
i. The incident ray
ii. normal to the surface
iii. The reflected ray
A) i,ii
B) i,iii
C) ii, iii
D) i,ii,iii
Answer:
D) i,ii,iii

7. Angle between normal and the incident ray
A) angle of incidence
B) angle of reflection
C) angle of vision
D) A & B
Answer:
A) angle of incidence

8. Which of the following is not a characteristic of the image of the plane mirror?
A) Object distance is equal to image distance.
B) Size of the object is equal to size of the image.
C) The image formed is always real and erect.
D) Laterally inverted image is formed.
Answer:
C) The image formed is always real and erect.

9. The distance of the object from the mirror is …………….. the distance of image from the mirror.
A) is equal to
B) is greater than to
C) is less than to
D) A & C
Answer:
A) is equal to

10. The size of image is not equal to that of the object in any situation.
A) plane mirror
B) convex mirror
C) concave mirror
D) none
Answer:
B) convex mirror

11. The distance of the image from the mirror is called
A) Image distance
B) Object distance
C) Normal
D) None
Answer:
A) Image distance

12. This type of image can catch on the screen
A) real
B) virtual
C) both
D) none
Answer:
A) real

13. Image formed by a plane mirror
A) erect & real
B) inverted & virtual
C) erect & virtual
D) inverted & real
Answer:
C) erect & virtual

14. No. of images formed when the angle between two plane mirrors is 60°
A) 4
B) 5
C) 6
D) 7
Answer:
B) 5

15. No. of images formed when the angle between two plane mirrors is 90°
A) 4
B) 2
C) 1
D) 3
Answer:
D) 3

16. No. of images formed when the angle between two plane mirrors is 0°
A) infinity
B) 5
C) 6
D) 0
Answer:
A) infinity

17. No. of images formed is 1, then the angle between two plane mirrors is
A) 0°
B) 90°
C) 180°
D) 360°
Answer:
C) 180°

18. The instrument which is used in submarines to see the objects or persons above the water level.
A) microscope
B) telescope
C) kaleidoscope
D) periscope
Answer:
D) periscope

19. Angle between two plane mirrors in periscope is
A) 0°
B) 90°
C) 180°
D) 360°
Answer:
A) 0°

20. The steel spoon can act as …
A) plane mirror
B) convex mirror
C) concave mirror
D) B & C
Answer:
D) B & C

21. The mirror forms all types of images
A) plane mirror
B) convex mirror
C) concave mirror
D) B & C
Answer:
C) concave mirror

22. The mirror is used as rear view mirror
A) plane mirror
B) convex mirror
C) concave mirror
D) B & C
Answer:
B) convex mirror

23. Which rule we should follow to protect eyes while watching TV or computer?
A) 20-20-20
B) 40-4-40
C) 10-10-10
D) 12-12-12
Answer:
A) 20-20-20

24. Which light is not dangerous to our eye?
A) yellow
B) red
C) blue
D) violet
Answer:
A) yellow

25. Which colour of light is composition of all colours?
A) yellow
B) red
C) blue
D) white
Answer:
D) white

II. Fill in the blanks

1. Light is a form of ………………. that helps us to see all the things around us.
2. Light comes from different objects called ………………. .
3. Objects that emit light are known as ………………. .
4. Sources that release light artificially [with human involvement] are called ………………. sources of light or artificial sources of light.
5. ………………. source emit light on their own.
6. The direction or path along which light travels is called ………………. .
7. The straight line indicates the of light and arrow mark indicates the ………………. of light from the source.
8. A bundle of light rays are called ………………. of light rays.
9. Light rays which travel parallel to each other are called ………………. of light rays.
10. Light rays which travel from different directions to meet at a point are called as ………………. of light rays.
11. Light rays which travel from a source moving in different directions are called as ………………. of light rays.
12. The process of bouncing back of light rays into the same medium after falling on a smooth or rotigh surface from the light source is called ………………. .
13. Objects are visible only when ………………. falls on the objects and bounces back to the eye.
14. Light rays from the sun fall on the mirror and bounced back and formed a spot of light on the wall. It is the image of ………………. .
15. The light rays that fall on the objects are called ………………. .
16. The light rays that bounce back from the objects are called ………………. .
17. Reflection from a ………………. surface is called regular reflection.
18. Reflection from an irregular or uneven surface is called ………………. reflection.
19. Clear images are formed in case of ………………. reflection.
20. Angle of ………………. is equal to Angle of reflection.
21. Incident and reflected rays are on either side of ………………. .
22. The angle made by incident ray with the normal is called ………………. .
23. The angle made by the reflected ray with the ………………. is called the angle of reflection.
24. The distance of the object from the mirror is called ………………. .
25. The distance of the image from the is called image distance.
26. When you are eating food with right hand it appears to be eating with left hand. This characteristic is called ………………. .
27. The image which cannot catch on the screen is called ………………. .
28. Plane mirror forms ………………. image.
29. The relation between number of images formed and the angle between two plane mirrors is ………………. .
30 . ………………. is an instrument used in submarines to see the objects or persons above the water level.
31. ………………. mirror reflect the light in different directions.
32. ………………. mirror reflect the light to one point.
33. A ………………. mirror forms real and virtual images, erect and inverted images, smaller, same size and bigger images depending on the position of object infront of it.
34. Ophthalmoscope is fitted with a ………………. mirror having a small hole near its center.
35. Dentists also use ………………. mirrors to get a bigger image of the teeth.
36. ………………. mirrors are used in head lights of the vehicles.
37. A piece of glass or any other transparent material with curved sides is called ………………. .
38. Lens which is thick in center and thin at the edges is called ………………. lens.
39. Lens which is thin in the centre and thick at the edges is called ………………. lens.
40. ………………. light has been proven effective in protecting retina than blue light which causes damage to retina.
41. Splitting of white light into seven colours is called ………………. .
Answer:

1. energy
2. sources of light
3. sources of light
4. man made
5. natural
6. a ray of light
7. path, direction
8. beam
9. parallel beam
10. Converging beam
11. Diverging beam
12. reflection of light
13. Light
14. sun
15. incident rays
16. reflected rays
17. smooth and shiny
18. irregular or diffused
19. regular
20. incidence
21. normal
22. angle of incidence
23. normal
24. object distance
25. mirror
26. lateral inversion
27. virtual image
28. virtual
29. 360°/θ -1
30. periscope
31. convex
32. concave
33. concave
34. concave
35. concave
36. concave
37. a lens
38. convex
39. concave
40. Yellow
41. dispersion

III. Match the following

1.

Group – A	Group – B
1) Natural source	a. cloth
2) Artificial source	b. steel plate
3) Regular reflection	c. star
4) Irregular reflection	d. candle

Answer:

Group – A	Group – B
1) Natural source	c. star
2) Artificial source	d. candle
3) Regular reflection	b. steel plate
4) Irregular reflection	a. cloth

2.

Group – A	Group – B
1) Convex mirror	a. make up
2) Concave mirror	b. ENT doctor
3) Plane mirror	c. magnifier
4) Convex lens	d. rear view

Answer:

Group – A	Group – B
1) Convex mirror	d. rear view
2) Concave mirror	b. ENT doctor
3) Plane mirror	a. make up
4) Convex lens	c. magnifier

3.

Group – A	Group – B
1) Periscope	a. concave mirror
2) Ophthalmoscope	b. convex mirror
3) Road safety	c. convex lens
4) Telescope	d. plane mirror

Answer:

Group – A	Group – B
1) Periscope	d. plane mirror
2) Ophthalmoscope	a. concave mirror
3) Road safety	b. convex mirror
4) Telescope	c. convex lens

4.

Group – A	Group – B
1) Convex mirror	a. inwards curve
2) Concave mirror	b. outwards curve
3) Plane mirror	c. thick at middle
4) Convex lens	d. plane surface
5) Concave lens	e. thin at middle

Answer:

Group – A	Group – B
1) Convex mirror	b. outwards curve
2) Concave mirror	a. inwards curve
3) Plane mirror	d. plane surface
4) Convex lens	c. thick at middle
5) Concave lens	e. thin at middle

5.

Group – A	Group – B
1) Virtual image	a. pass through one point
2) Real image	b. bundle of rays
3) Ray	c. caught on the screen
4) Beam	d. seen in the mirror
5) Converging	e. path of light

Answer:

Group – A	Group – B
1) Virtual image	d. seen in the mirror
2) Real image	c. caught on the screen
3) Ray	e. path of light
4) Beam	b. bundle of rays
5) Converging	a. pass through one point

6.

Group – A	Group – B
1) Incident angle	a. perpendicular line to surface
2) Reflecting angle	b. angle of incidence angle of reflection
3) Normal	c. angle between normal and reflected ray
4) First law of reflection	d. normal, incident ray, reflected ray are in one plane
5) Second law of reflection	e. angle between normal and incident ray

Answer:

Group – A	Group – B
1) Incident angle	e. angle between normal and incident ray
2) Reflecting angle	c. angle between normal and reflected ray
3) Normal	a. perpendicular line to surface
4) First law of reflection	b. angle of incidence angle of reflection
5) Second law of reflection	d. normal, incident ray, reflected ray are in one plane

7.

Group – A	Group – B
1) Convex mirror	a. converges
2) Concave mirror	b. diverges
3) Plane mirror	c. parallel rays
4) Sun	d. irregular reflection
5) Thermocol sheet	e. regular reflection

Answer:

Group – A	Group – B
1) Convex mirror	b. diverges
2) Concave mirror	a. converges
3) Plane mirror	e. regular reflection
4) Sun	c. parallel rays
5) Thermocol sheet	d. irregular reflection

Do You Know?

→ We cannot see the real image with our naked eye. But we can catch it on screen. Whereas we can see the virtual image in the mirror with our naked eye. But we cannot catch it on screen.

→ In olden days the concave mirrors can also be used as weapons. Archimedes, a Greek scientist used this mirror as weapon, 2000 years ago. When the Romans attacked Syracus, a coastal City – state in Greece, Archimedes arranged concave mirrors. The mirrors could be moved in any direction. They were positioned such that they reflected the sunlight on the Roman soldiers. The soldiers were dazzled by the sunlight. They did not know what was happening. Roman soldiers got confused and returned back.

→ Convex mirrors are used in Automatic Teller Machine (ATM) for security purpose to get a wider background look. This is to avoid others from over looking at your password.

These AP 7th Class Science Important Questions 7th Lesson Reproduction in Plants will help students prepare well for the exams.

AP Board 7th Class Science 7th Lesson Important Questions and Answers Reproduction in Plants

Question 1.
What is reproduction?
Answer:
The process of giving rise to new ones of their own kind is called Reproduction.

Question 2.
What are the two types of reproduction?
Answer:
Generally, plants reproduce in two ways. They are 1) Sexual Reproduction and 2) Asexual Reproduction.

Question 3.
What is Sexual reproduction?
Answer:
Reproduction in plants with seeds is called Sexual Reproduction.

Question 4.
What is Asexual reproduction?
Answer:
Reproduction in plants without seeds is called Asexual Reproduction.

Question 5.
Give examples for plants reproduce through seeds.
Answer:
Tamarind, drumsticks, mango, neem etc. reproduce through seeds.

Question 6.
Give examples for plants reproduce without seeds.
Answer:
Jasmine, banana, rose etc. reproduce without seeds.

Question 7.
Give examples for plants reproduce by both with seeds and without seeds.
Answer:
Curry leaf, Coriander etc. can reproduce by both means.

Question 8.
Mention some asexual reproduction methods.
Answer:
Binary fission, budding, fragmentation, spore formation etc.

Question 9.
What are incomplete flowers?
Answer:
Flowers which do not have any one of the four whorls are called Incomplete flowers.

Question 10.
Give examples for complete flowers.
Answer:
Hibiscus, Datura

Question 11.
Give examples for incomplete flowers.
Answer:
Pumpkin, Ridge guard

Question 12.
What are unisexual flowers?
Answer:
In some flowers either androecium or gynoecium is present. Such type of flowers are called unisexual flowers.

Question 13.
What are bisexual flowers?
Answer:
Generally, both androecium and gynoecium are present in the same flower in most of the plants. This type of flowers are called as bisexual flowers.

Question 14.
What are male flowers?
Answer:
Unisexual flowers that contain only androecium are called male flowers.

Question 15.
What are female flowers?
Answer:
Unisexual flowers that contain only gynoecium are called female flower.

Question 16.
What is the third whorl of a flower?
Answer:
The third whorl of a flower is androecium. This is the male reproductive part of the flower.

Question 17.
What is the 4th whorl of a flower?
Answer:
The fourth whorl of a flower is gynoecium. This is the female reproductive part of the flower.

Question 18.
What are the reproductive parts of a flower?
Answer:
Androecium and Gynoecium are the reproductive parts of a flower.

Question 19.
What is pollination?
Answer:
The process of transferring pollen grains from anther to stigma is called as Pollination.

Question 20.
What is self-pollination?
Answer:
If the pollen grains are transferred from the anther of a flower to stigma of the same flower, is known as SELF POLLINATION.

Question 21.
What is cross pollination?
Answer:
If the transfer of pollen grains takes place from the anther of one flower to the stigma of another flower, it is called CROSS POLLINATION.

Question 22.
Mention some pollinating agents.
Answer:
Insects, birds, animals, air and water are the pollinating agents.

Question 23.
Why do plants try to spread their seeds to distant places?
Answer:
All the plants try to spread their seeds to distant places to increase the chance of survival and propagation.

7th Class Science 7th Lesson Reproduction in Plants Short Questions and Answers

Question 1.
What is reproduction? How is it useful to the plants?
Answer:

1. The process of giving rise to new ones of their own kind is called Reproduction.
2. Reproduction helps to increase their number and continue their existence.
3. All plants produce new once like them.
4. There is no existence for plants without reproduction.

Question 2.
Write the differences between sexual and asexual reproductions in plants.
Answer:

Sexual reproduction	Asexual reproduction
1. Reproduction in plants with seeds is called Sexual Reproduction.	Reproduction in plants without seeds is called Asexual Reproduction.
2. Pollination takes place	Pollination does not takes place
3. Fertilization occurs	There is no fertilization
4. Occurs in most of the plants like Datura, Mango etc.	Occurs in few plants like Bryophyllum, banana etc.

Question 3.
Write the differences between calyx and corolla.
Answer:

Calyx	Corolla
1. First whorl of the flower.	Second whorl of the flower.
2. They consisting of sepals.	They consisting of petals.
3. They are green in colour.	They are in different colours in different plants.
4. They give protection to the inner parts during bud condition.	They attract the insects and helps in pollination.

Question 4.
Write the differences between bisexual flowers and unisexual flowers?
Answer:

Bisexual flowers	Unisexual flowers
Both androecium and gynoecium are present.	Either androecium or gynoecium is present.
Generally, they have four whorls.	Generally, they have only three whorls.
They are complete flowers. Ex: Hibiscus, datura	They are incomplete flowers. Ex : Ridge gourd, bottle gourd

Question 5.
Differentiate male and female flowers.
Answer:

1. Unisexual flowers that contain only androecium are called male flowers.
2. Unisexual flowers that contain only gynoecium are called female flowers.

Question 6.
How can you identify a female flower?
Answer:

1. Female flowers are not difficult to identify.
2. Notice the flowers on the variety of gourd creepers we grow around our home.
3. Commonly below the petals of the flower are just a stalk found in the male flowers, while in the female flowers, a small berry-like form is seen below the flower which is ready to bear fruit in further days.
4. By observing the presence of that berry-like form, we can identify the female flowers.

Question 7.
Write the differences between self-pollination and cross pollination.
Answer:

Self-pollination	Cross pollination
If the pollen grains are transferred from the anther of a flower to stigma of the same flower, is known as SELF POLLINATION.	If the transfer of pollen grains takes place from the anther of one flower to the stigma of another flower, it is called CROSS POLLI – NATION.
It is possible only in bisexual flowers	It happens in both unisexual and bisexual flowers.
It may happen even without blooming of the flower	It happens only after blooming of the flower
Pollinating agents such as insects, air, water etc. may not necessary.	Pollinating agents such as insects, air; water etc. are necessary.

Question 8.
How do insects and some birds help in pollination?
Answer:

1. Insects like butterflies, honeybees, bumble bees, humming birds, bats, ants visit the flowers in search of nectar.
2. When insects come in contact with a flower, the pollen grains stick to their legs and wings.
3. When insects visit another flower, the pollen fall on its slimy stigma.
4. Thus they help in pollination.

Question 9.
How do fertilization takes place in plants?
Answer:

1. The pollen grains which fall on the stigma of a flower germinates.
2. A pollen tube is formed from the pollen grains.
3. The pollen tube travels from stigma to the ovules in the ovary.
4. Fertilization and zygote formation occur in ovary.
5. The zygote develops into an embryo.

Question 10.
What changes will come in the flower after fertilization?
Answer:

1. After fertilization the ovary ripens and turns into fruit.
2. The remaining floral parts will fall off.
3. The ovules become the seeds.

Question 11.
What is seed dispersal? Mention different means of seed dispersal.
Answer:

1. Spreading of seeds from one place to another place is called seed dispersal.
2. Seed dispersal may happen through wind, water, animals, birds, man and even through some mechanical processes such as bursting of fruits.

7th Class Science 7th Lesson Reproduction in Plants Long Questions and Answers

Question 1.
What is vegetative propagation? Mention different vegetative propagation methods and their examples.
Answer:
Reproduction in plants through vegetative parts such as stem, root, and leaves is called vegetative propagation.

Vegetative propagation method	Part involved	Example
1. Through suckers	Stem	Banana, Chrysanthemum
2. Through nodes	Stem	Mint plant, Sugarcane
3. Through eyes (buds)	Stem	Potato
4. Through Stem cutting	Stem	Sugarcane, Rose, Hibiscus
5. Through root cutting	Root	Carrot, Beetroot
6. Leaf buds	Leaf	Bryophyllum( Ranapala )
7. Layering	Stem	Jasmine, Jaji, Bougainvillea, Strawberry
8. Grafting	Stem	Mango, Rose

Question 2.
Explain the process of ground layering.
Answer:

Ground Layering

1. Layering is done with branches nearer to the ground.
2. Remove the bark of the stem at one place.
3. Bend the branch into the ground and cover it with soil.
4. Within one month roots will develop from that branch.
5. Separate it from the mother plant and plant it where ever you want.
6. This method is useful to propagate Jasmine, Jaji, Bougainvillea, Strawberry etc. Plants with creeping stem.

Question 3.
What is grafting? Explain the method of grafting.
Answer:
Grafting is a technique where two plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion, while the lower part is called the stock.

Procedure:

1. Remove the bark of the Stock and Scion plants in such a way that removed portions face each other.
2. The parts where bark is removed are joined tightly with the help of a jute twine.
3. Wrap and tie with a polythene paper.
4. After a month, cut the upper part of Stock and lower part in Scion.
5. Within an another month the Scion attaches to the Stock and grows.
6. Now remove the new branches which grow on Stock to facilitate the growth of Scion.

Question 4.
Describe the structure of a flower.
Answer:
Flower is the sexual part of a plant. The green part which connects the flower to stem is called the stalk. The stalk bears a slightly swollen head called Thalamus.

Over the thalamus floral parts are arranged in four whorls.

Calyx:
The green cup shaped leaf like, fused structures that covers the internal parts are Sepals. They are collectively called as Calyx. (Whorl 1)

Corolla:
The white or brightly coloured structures are called Petals. They are collec¬tively called as Corolla. (Whorl 2) .

Androecium:
The soft elongated structures attached to the petals are called Stamens. All the stamens are collectively called Androecium (Whorl 3). This is the male reproductive part of the flower. Each stamen has a swollen structure at the top called Anther.

Gynoecium:
A bulged structure seated on the thalamus is called Ovary which continues into a fine tube like structure Style with a slimy bead like tip called Stigma. These are collectively called the pistil Gynoecium (Whorl 4). This is the female reproductive part of the flower’

Question 5.
Write the differences between Androecium and Gynoecium.
Answer:

Androecium	Gynoecium
This is the third whorl of the flower.	This is the fourth and inner most whorl of the flower.
This is male reproductive part of the flower.	This is female reproductive part of the flower.
It consisting of stamens.	It consisting of ovary, style and stigma.
Number of stamens are more.	In general gynoecium consists of single ovary.
They produce pollen grains.	It produce eggs or ova.
Pollen grains are released from stamens for pollination	Fertilization occurs in ovary.
Generally they drop off after, fertilization	Ovary develop into fruit after fertilization.

Question 6.
Draw the different whorls of a flower.
Answer:

Question 7.
Do you find any relationship between the weight of the seeds and the dispersal mechanism? Discuss with suitable examples.
Answer:

1. I find relationship between the weight of the seeds and the dispersal mechanism.
2. For example : Seeds of calotropis.
   a) These are light and have hairy structure at one end.
   b) So they travel with wind and settle at a suitable place to germinate.
   c) Milk weed, cotton seeds, etc. are all dispersed by wind.
3. Another example : Coconut fruit
4. a) The outer covering of the seed has empty spaces filled with air and are fibrous,
   b) The coconut fruit floats on water and reaches the ground some where. There it germinates. Seeds of lotus is another example.
5. Another example : Neem fruit.
   a) Birds like Bulbuls, Mynahs, crows eat the outer fleshy part gets digested in the food canal and the seed coats of them become tender.
   b) They are then dispersed to other places as bird droppings.
6. Similarly animals, Human beings carry the seeds to other places.

AP Board 7th Class Science 7th Lesson 1 Mark Bits Questions and Answers Reproduction in Plants

I. Multiple Choice Questions

Choose the correct answer and write its letters in the brackets.

1. Seeds are related to
A) stem
B) root
C) flower
D) leaf
Answer:
C) flower

2. Sugarcane propagates through
A) nodes
B) leaf
C) root
D)suckers
Answer:
A) nodes

3. Ground layering is seen in
A) Jasmine
B) Bougainvillea
C) Strawberry
D) All
Answer:
D) All

4. Which one is formed from layering branch?
A) Roots
B) Leaves
C) Nodes
D) Fruits
Answer:
A) Roots

5. The rooted plant in grafting is called as
A) Scion
B) Stock
C) Node
D) Cutting
Answer:
B) Stock

6. In grafting which have desirable characters
A) Scion
B) Stock
C) Root
D) Leaf
AnsA) Scionwer:

7. This symbol represents
A) Female
B) Male
C) Both
D) Flower
Answer:
B) Male

8. This symbol represents
A) Male
B) Female
C) Both
D) Pollination
Answer:
B) Female

9. This diagram indicates
A) Pistil
B) Corolla
C) Stamens
D) Sepals
Answer:
A) Pistil

10. How many whorls that the complete flower has
A) 2
B) 3
C) 4
D) 5
Answer:
C) 4

11. Complete flowers also called as
A) Male flower
B) Female flower
C) Unisexual flower
D) Bisexual flower
Answer:
D) Bisexual flower

12. Ipomea have
A) Unisexual flower
B) Bisexual flower
C) Male flower
D) Female flower
Answer:
B) Bisexual flower

13. The zygote develops into
A) Embryo
B) Fruit
C) Flower
D) Stem
Answer:
A) Embryo

14. Which of the flower colour change after fertilization?
A) Mango
B) Rose
C) Cotton
D) Neam
Answer:
C) Cotton

15. Seeds compitect for
A) Soil
B) water
C) light
D) All
Answer:
D) All

16. Which process makes life immortal?
A) Reproduction
B) Digesion
C) Respiration
D) Circulation
Answer:
A) Reproduction

17. Transfer of pollen to stigma is
A) Pollination
B) Fertilization
C) Germination
D) Growth
Answer:
A) Pollination

18. Assertion (A) : A stamen has 2 parts.
Reason (R) : Filament and anther are parts of a stamen.
A) Both ’A’ and R’ are true and R’ is the correct explanation of ‘A’.
B) Both A’ and ‘R’ are true but ‘R’ is not the correct explanation of ‘A‘.
C) ‘A’ is true but R’ is false.
D) A’ is false but ‘R’ is true.
Answer:
A) Both ’A’ and R’ are true and R’ is the correct explanation of ‘A’.

19. Assertion (A) : Parts of pistil are anther and filament.
Reason (R) : Bisexual flowers are those which contain both stamen ahd pistil.
A) Both ‘A’ and ‘R’ are true and ‘R’ is the correct explanation of ‘A’.
B) Both ‘A’ and ‘R’ are true but ‘R’ is. not the correct explanation of ‘A’.
C) ‘A’ is true but ‘R’ is false.
D) ‘A’ is false but ‘R’ is true.
Answer:
D) ‘A’ is false but ‘R’ is true.

20. Assertion (A) : A flower may either have a male or a female part.
Reason (R) : A flower having both male and female parts is called bisexual flower.
A) Both A’ and ‘R’ are true and ‘R’ is the correct explanation of ‘A’.
B) Both ‘A’ and ‘R’ are true but ‘R’ is not the correct explanation of ‘A’.
C) ‘A’ is true but ‘R’ is false.
D) ‘A’ is false but ‘R’ is true.
Answer:
B) Both ‘A’ and ‘R’ are true but ‘R’ is not the correct explanation of ‘A’.

21. Statement (I): After fertilization the ovary becomes the fruit and ovules the seeds.
Statement (ii) : Study of pollen grains is called polynology.
A) Statement (i) is correct while statement (ii) is incorrect.
B) Statement (ii is correct while statement (i) is correct.
C) Both statements are correct.
D) Both statements are incorrect.
Answer:
C) Both statements are correct.

22. It is the seat on which the parts of a flower are present.
A) Corolla
B) Thalamus
C) Calyx
D) Androecium
Answer:
B) Thalamus

23. It has funnel shape.
A) Corolla
B) Sepals
C) Calyx
D) Thalamus
Answer:
A) Corolla

24. This is the male part of the flower.
A) Gynoecium
B) Androecium
C) Petals
D) Sepals
Answer:
B) Androecium

25. This is the female part of a flower.
A) Petals
B) Calyx
C) Gynoecium
D) Androecium
Answer:
C) Gynoecium

26. An example for unisexual flower.
A) Bittergourd
B) Datura
C) Ipomea
D) Hibiscus
Answer:
A) Bittergourd

27. This is a bisexual flower.
A) Papaya
B) Cucumber
C) Bottlegourd
D) Hibiscus
Answer:
D) Hibiscus

28. The fleshy base to which all the floral parts are attached to is
A) Pedicel
B) Sepals
C) Thalamus
D) Petals
Answer:
C) Thalamus

29. The pollen grains are found in
A) Ovule
B) Anthers
C) Ovary
D) Stigma
Answer:
B) Anthers

30. The number of stamens present in Datura :
A) 5
B) 3
C) 6
D) 10
Answer:
A) 5

31. Ovules develop into :
A) flowers
B) plants
C) leaf
D) seeds
Answer:
D) seeds

32. The pollen grains contain
A) male garnets
B) female garnets
C) filaments
D) Stigma
Answer:
A) male garnets

33. It is a ……………
A) Unisexual flower
B) Bisexual flower
C) Female flower
D) Male flower
Answer:
C) Female flower

34. In which type of flower this part is present?
A) Male flower
B) Bisexual flower
C) Both A & B
D) None of these
Answer:
C) Both A & B

35. Identify the part of flower
A) Stamen
B) Pistil
C) Petals
D) Sepals
Answer:
A) Stamen

36. Identify the part of flower.
A) Stamen
B) Pistil
C) Petals
D) Sepals
Answer:
B) Pistil

37. It shows that
A) T.S of flower
B) L.S of flower
C) T.S of stem
D) T.S of root
Answer:
B) L.S of flower

38. Pollen grains are formed from
A) Stamen
B) Pistil
C) Ovary
D) Sepals
Answer:
A) Stamen

39. In the pollination what is transfer from anther to stigma?
A) Ovule
B) Zygote
C) Seed
D) Pollengrain
Answer:
D) Pollengrain

40. Agents of pollination
A) Birds
B)Insects
C) Air
D) All of these
Answer:
D) All of these

41. New plants grow from the following part of a plant is not a vegetative reproduction
A) Root
B) Stem
C) Leaf
D) Flower
Answer:
D) Flower

42. This develops as fruit.
A) Ovary
B) Ovule
C) Petals
D) Flower
Answer:
A) Ovary

43. Ovules develop into
A) fruit
B) seed
C) flower
D) plant
Answer:
B) seed

44. Dispersal of this seed is by water.
A) Coconut
B) Soap nut
C) Neem
D) Milk weed
Answer:
A) Coconut

45. Dispersal of calotropis is through
A) Water
B) Animals
C) Wind
D) Humans
Answer:
C) Wind

46. These seeds are dispersed by animals.
A) Fleshy fruits
B) Coconut
C) Neem
D) Balsam
Answer:
A) Fleshy fruits

47. Neem seed is dispersed to other places by
A) Animals
B) Human beings
C) Birds
D) Water
Answer:
C) Birds

48. Dispersal by bursting of these fruits is done.
A) Neem
B) Coconut
C) Fleshy fruits
D) Bhendi
Answer:
D) Bhendi

49. People transferred these seeds across the globe.
A) Coconut
B) Neem
C) Soap nut
D) Sugarcane
Answer:
D) Sugarcane

50. Among the following dispersal of seed occurs through wind in
A) Coconut
B) Lotus
C) Milkweed
D) Mango
Answer:
C) Milkweed

51. Seeds of Lotus travel by
A) Birds
B) Insects
C) Animals
D) Water
Answer:
D) Water

52. These are carried by birds
A) Maple
B) Milkweed
C) Lotus
D) Neem
Answer:
D) Neem

53. On drying the pod explodes releases seeds with great force in
A) Mustard
B) Sugarcane
C) Pears
D) Tomato
Answer:
A) Mustard

54. These seeds are dispersal through
A) Water
B) Wind
C) Animals
D) Birds
Answer:
B) Wind

55. These seeds are dispersal through
A) Wind
B) Water
C) Animals
D) Birds
Answer:
B) Water

56. Seeds of sweet and fleshy fruits can dispersal through
A) Human beings
B) Birds
C) Animals
D) All of these
Answer:
C) Animals

57. Seed dispersal is essential for survival of
A) Plants
B) Animals
C) Birds
D) Human beings
Answer:
A) Plants

58. Cotton seeds have the following structures
A) Wing like outer growths
B) Hooks
C) Hairy parts
D) Thorns
Answer:
C) Hairy parts

59. The following seeds dispersal through human beings
A) Bhendi
B) Coconut
C) Tomato
D) Cotton
Answer:
C) Tomato

60. Identify the wrong statement.
A) All the seeds of a fruit should be able to germinate
B) Some seeds germinate but plants die before maturation
C) Some seeds never germinate
D) All seeds do not germinate
Answer:
A) All the seeds of a fruit should be able to germinate

61. This seed is dispersed by
A) Water
B) Air
C) Animals
D) Bursting
Answer:
C) Animals

62. Dispersal of seeds by bursting of fruits happens in
A) Sugarcane
B) Coconut
C) Lotus
D) Ladies finger
Answer:
D) Ladies finger

II. Fill in the blanks.

1. The propagation of Banana is through ………………………. .
2. The propagation of sugarcane is done by planting ………………………. .
3. Mint is propagated through ………………………. .
4. In potatoes, ………………………. are used for propagation.
5. In onions ………………………. are used for propagation.
6. Example for rhizome is ………………………. .
7. Example for corm is ………………………. .
8. Example for stem cutting is ………………………. .
9. Examples for ground layering are ………………………. .
10. Artificial propagation method used for getting plants with desired characters is ………………………. .
11. Sepals of a flower collectively called as ………………………. .
12. Petals of a flower are are collectively known as ………………………. .
13. Calyx is present in ………………………. whorl.
14. Corolla is present in ………………………. whori.
15. The male reproductive part of the flower is ………………………. .
16. The female reproductive part of the flower is ………………………. .
17. Androecium consists of ………………………. .
18. Gynoecium consists of ………………………. .
19. Androecium is present in ………………………. whorl of the flower.
20. Gynoecium is present in ………………………. whorl of the flower.
21. The smooth yellow coloured powder in anther is called ………………………. .
22. Transferring pollen from anther to stigma of the same flower is
23. Transferring of pollen grains from anther of one flower to stigma of another flower is known as ……………….. .
24. When pollen grains fall on stigma is ………………………. formed.
25. The fusion of pollen grains with ovules in ovary is known as ………………………. .
26. Fertilization results in the formation of ………………………. .
27. After fertilization, ovary ripes and turn into a ………………………. .
28. After fertilization, ovules turn into ………………………. .
29. Seeds with wings are carried away by ………………………. .
30. Example for seed dispersal through water is ………………………. .
31. Seeds of calotropis dispersed with the help of ………………………. .
32. Seeds of fleshy fruits are dispersed through ………………………. .
33. Seeds having hooks are dispersed with the help of ………………………. .
34. Neem seeds are dispersed with the help of ………………………. .
35. Seeds having hairs dispersed through ………………………. .
36. Dispersal of seed take place by bursting of fruits can be seen in ………………………. .
37. Lotus seeds are dispersed through ………………………. .
38. In Mustard, seeds dispersal takes place through ………………………. .
39. Seeds dispersed through aeroplanes and ships are ………………………. .
40. Flower shown in the picture is ………………………. .
41. Grafting technique is used in the plants like ………………………. for getting desired characters.
Answer:

1. suckers
2. nodes of sugarcane
3. cut the twigs with nodes and sow them
4. eyes
5. Bulb
6. Ginger
7. colocasia
8. rose
9. Jasmine, Jaji
10. grafting
11. Calyx
12. Corolla
13. 1st
14. 2nd
15. Androecium
16. Gynoecium
17. Stamens
18. Ovary with style and stigma
19. 3rd
20. 4th
21. pollen grains
22. Self – pollination
23. cross – pollination
24. pollen tube
25. fertilization
26. zygote
27. fruit
28. seeds
29. wind
30. coconut, louts
31. wind
32. animals, birds and man
33. animals
34. birds
35. wind
36. bhendi, balsam
37. water
38. bursting mechanism
39. pulses, wheat, paddy
40. Unisexual flower (or) incomplete flower
41. mango, guava etc.

III. Match the following

1.

Group – A	Group – B
1. Datura	a) Bursting Mechanism
2. Cucumber	b) Gynoecium
3. Papaya	c) Androecium
4. Stamen	d) Male and female flowers are on different plants.
5. Pistil	e) Male and female flowers are on same plant.
	f) Complete flower

Answer:

Group – A	Group – B
1. Datura	f) Complete flower
2. Cucumber	e) Male and female flowers are on same plant.
3. Papaya	d) Male and female flowers are on different plants.
4. Stamen	c) Androecium
5. Pistil	b) Gynoecium

2.

Group – A	Group – B
1. Fertilization	a) Birds
2. Calotropis	b) Water dispersal
3. Coconut	c) Animals
4. Seeds of grass	d) Wind dispersal
5. Neem	e) Zygote
	f) Bursting mechanism

Answer:

Group – A	Group – B
1. Fertilization	e) Zygote
2. Calotropis	d) Wind dispersal
3. Coconut	b) Water dispersal
4. Seeds of grass	c) Animals
5. Neem	a) Birds

3.

Group – A	Group – B
1. Ovary	a) Wind dispersal
2. Ovules	b) Bursting mechanism
3. Anther	c) Nodes
4. Maple	d) Pollengrain
5. Balsam	e) Seeds
	f) Fruit

Answer:

Group – A	Group – B
1. Ovary	f) Fruit
2. Ovules	e) Seeds
3. Anther	d) Pollengrain
4. Maple	a) Wind dispersal
5. Balsam	b) Bursting mechanism

4.

Group – A	Group – B
1. Suckers	a) Nodes
2. Rhizome	b) Colocasia
3. Bulb	c) Potato
4. Eyes	d) Onion
5. Corm	e) Ginger
	f) Banana

Answer:

Group – A	Group – B
1. Suckers	f) Banana
2. Rhizome	e) Ginger
3. Bulb	d) Onion
4. Eyes	c) Potato
5. Corm	b) Colocasia

5.

Group – A	Group – B
1. Sugar cane	a) Suckers
2. Seeds of Drumsticks	b) Bursting mechanism
3. Seeds of Xanthium	c) Man
4. Seeds of Custard apple	d) Animals
5. Seeds of Lady’s finger	e) Wind
	f) Nodes

Answer:

Group – A	Group – B
1. Sugar cane	f) Nodes
2. Seeds of Drumsticks	e) Wind
3. Seeds of Xanthium	d) Animals
4. Seeds of Custard apple	c) Man
5. Seeds of Lady’s finger	b) Bursting mechanism

6.

Group – A	Group – B
1. Rose	a) Buds on leaf
2. Jasmine	b) Rhizome
3. Mango	c) Suckers
4. Chrysanthemum	d) Grafting
5. Turmeric	e) Layering
	f) Stem cutting

Answer:

Group – A	Group – B
1. Rose	f) Stem cutting
2. Jasmine	e) Layering
3. Mango	d) Grafting
4. Chrysanthemum	c) Suckers
5. Turmeric	b) Rhizome

Do You Know?

→ You will be amazed that banana contains seeds. The rose plant also has red fruits with seeds. Do you know that Nandivardhanam and Hibiscus also have seeds* There are nuts and seeds in the rose and banana plants that grow wild without human interference in forests. The rose and banana plants that are found in our surroundings have no seeds. Do you know the reason? Our ancestors grew these plants with seeds of the plants with seeds of the plants that were found in the forest.

With the efforts made over many generations to propagate them as plants with favourable characteristics, they became seedless plants.

→ Can you imagine a single plant giving 40 types of fruits such as peaches, apricots, plums, cherries, nectarines and so on? Such types of plants can be produced by Grafting.

These AP 7th Class Science Important Questions 6th Lesson Electricity will help students prepare well for the exams.

AP Board 7th Class Science 6th Lesson Important Questions and Answers Electricity

Question 1.
How does a bulb glow?
Answer:
When we switched ON the bulb, electricity flows through the wire and makes the bulb glow.

Question 2.
What is cell?
Answer:
A cell is a device used to generate electricity.

Question 3.
What are the anpde and cathode in a cell?
Answer:

1. Anode and cathode are the two electrodes in a cell.
2. The positive electrode is called anode and the negative electrode is called cathode.

Question 4.
What is the electrolyte in a cell?
Answer:
The electrolyte is a chemical component that conducts the electricity.

Question 5.
Which parts of the battery function as an anode and a cathode?
Answer:

1. The container which is made of zinc metal works as the cathode (negative terminal).
2. A carbon rod with a metal cap works as an anode (positive terminal).

Question 6.
Name the common chemicals present in the dry cell.
Answer:

1. Carbon powder
2. Ammonium chloride.

Question 7.
What Is a battery?
Answer:
A group of cells Is called a battery.

Question 8.
Write different types of cells.
Answer:
1) Dry cell, 2) Lithium cell, 3) Button ceils, 4)Alkaline cell

Question 9.
Write one difference between fuse and MCB.
Answer:
There is no need to change the fuse wire in MCB. But fuse wire has to be changed whenever it melts in fuse device.

Question 10.
What precantion do you take while connecting copper wire in the circuit?
Answer:
While connecting copper wire in the circuit, the copper coating at the two ends erf the copper wire should be cleaned or scratched.

Question 11.
What is a simple electric circuit?
Answer:
A simple electric circuit consisting of a battery, a bulb, a switch, and connecting wires.

Question 12.
What are circuit diagrams?
Answer:
The diagrams which show the arrangement of electric components in a circuit are called circuit diagrams.

Question 13.
Write the common sequence of components in electric circuit diagram.
Answer:
Positive terminal of the cell → wire → bulb → wire → switch → wire → negative terminal of the cell.

Question 14.
What is the tearing effect of electricity?
Answer:
The production of heat due to the flow of electricity through a wire is called heating effect of electricity.

Question 15.
Name the metal used as a filament in the iron box and buld?
Answer:

1. Generally, the filament in an iron box is made up of Niehrome.
2. The filament in a bulb is made of Tungsten.

Question 16.
What is magnetic effect of electricity?
Answer:
The production of magnetic force due to the flow of electricity thrombi a wire is called Magnetic effect of electricity.

Question 17.
What are electromagnets?
Answer:
The devices which act as magnets when electricity passes through them are called electromagnets.

Question18.
On what principle do electric cranes work?
Answer:
Electric cranes are worked on the principle of magnetic effects of electricity.

Question 19.
Answer:

1. By using repulsion property of a magpet, a magnetic object can levitate.
2. Electromagnetic train runs on this principle.

Question 20.
How does electricity bill calculated?
Answer:
Generally, electricity bills are calculated on the basis of number of units of electricity consumed.

Question 21.
What is wattage of a bulb? What does it mean?
Answer:

1. 1) The wattage measures how powerful the electric device is.
2. The brighter the bulb, the higher its wattage and more the electricity used by it.

Question 22.
What is meant by KWH?
Answer:

1. Wiser? I kilo watt is used per one hour, it Is considered as 1 kilo watt hour (KWH)
2. 1 KWH = 1 UNIT of electricity.

Question 23.
What is the unit of electricity consumption?
Answer:
Kilo watt hour (or) UNIT.

Question 24.
From where electricity soppiied to owr booses?
Answer:
Electricity supplied to our houses comes ban the power stations and substations.

Question 25.
Where do we use lithium-ion cells and why?
Answer:
Lithium ion cells are rechargeable and are used in mobile phones, laptops etc.

Question 26.
Where do we use button cells?
Answer:
Button cells are used in wrist watches, laser lights. thermometers (electronic), computers etc.

Question 27.
Where is the use of a switch?
Answer:
Switch is used to open or dose a circuit.

Question 28.
Write different types of Im21» which areasedht omr daily life.
Answer:
In our daily life we use different types of bulbs. Some of them are Incandescent bulb, fluorescent both (tube light). CFL (Compact Fluorescent Lamp), LED bulb etc.

Question 29.
What is the use of parallel connection of cells in a circuit?
Answer:
The parallel connection of cells, increases the battery life.

Question 30.
Guess, what happens if one of bulbs is burnt in a series connection?
Answer:
It one of the bulbs is burnt, remaining bulbs also not glow because of circuit is opened.

Question 31.
What are the material required to make a cell with lemons?
Answer:
Zinc plate, copper plate, a small bulb, or LED, connecting wires, crocodile dips, and lemons.

Question 32.
Where do you find series and parallel connections of bulbs in your real life?
Answer:

1. Parallel connections of bulbs are found in houseshold connections.
2. Series connections of bulbs are found in decorative purpose connections.

Question 33.
What are the risks of electric shock?
Answer:
Explosure to electricity may result in no injury at all or may result in major damage or sometimes lead to death also.

7th Class Science 6th Lesson Electricity Short Questions and Answers

Question 1.
Answer:

1. A cell is device used to generate electricity.
2. It contains two elect rides and a chemical.
3. When electrodes come in contact with electrolyte, a chemical reaction takes place inside the cell to produce electricity.
4. It converts the chemical energy into electrical energy.
5. When electrodes and connected to the wires in a circuit, electricity passes through them.

Question 2.
What are the main components of a cell? Explain.
Answer:

1. A cell is a device used to generate electricity.
2. It mainly consists of two components.
   i) Electrolyte : This is a chemical component that conducts the electricity.
   ii) Electrodes : There are two electrodes in a cell. One is positive electrode called anode and the other is negative electrode called cathode.

Question 3.
Why and how do we save electricity?
Answer:

1. Our country faces shortage of electricity.
2. So, we should use electricity careful! and only when it is needed.

Question 4.
How long a dry cell works?
Answer:

1. The cell can supply electricity in a circuit for a period of time.
2. After that, chemicals present in it get exhausted and it cannot produce electricity.

Question 5.
Why should we replace an ordihary bulb with a LED bulb?
Answer:

1. The ordinary bulb we use gives us light and also heat.
2. This is not desirable.
3. This results in the wastage of electricity.
4. Hence, we should replace an ordinary bulb with a LED bulb.
5. LED bulbs consume less electricity than ordinary bulb.

Question 6.
How do you find an electrical device which consumers less electricity?
Answer:

1. Now-a-day every electrical device is marked with a power saving guide which contains star symbols.
2. The number of stars on them indicates the energy efficiency of that device.
3. The electrical appliance with more stars consumes less electricity.
4. Hence, it is advised to select electrical appliances with more stars.

Question 7.
How does an electric fuse protect home appliances?
(OR)
How do you appreciate the electric fuse?
Answer:

1. Electric appliances may get damaged when excess of electricity flows through them.
2. To protect them from such accidents, a safety device called electric fuse is used.
3. Electric fuse has a body made of ceramic.
4. It has two points for connecting the fuse wire.
5. If there is an overload of electricity in the circuit, the fuse wire melts because of low melting point.
6. This breaks the circuit and helps in preventing damage to electrical appliances.

Question 8.
How does a MCB work?
(OR)
How do you appreciate the role of MCB in the protection of electrical home appliances?
Answer:

1. MCB means Miniature Circuit Breaker.
2. It is being used in place of electric fuses.
3. There is a switch which automatically turns off when electricity in circuit exceeds the safe limit.
4. So, the circuit is opened.
5. We just need to switch ON to resume electric supply.
6. At present MCB is available with automatically resumed built-in mechanism.
7. MCB is better than electric fuses.
8. There is no need to change it often.
9. But fuse wire has to be changed whenever it melts.
10. Hence, I appreciate the MCB for protecting home appliances.

Question 9.
What is series connection of devices? What happens if any one of the devices is removed?
Answer:

1. If the second terminal of the first device is connected to the first end of the second device, such type of connection is called series connection.
2. In series connection electricity has only one path.
3. If any of them is removed or not functioning properly, it becomes an open circuit.

Question 10.
What is parallel connection of devices ? What is its advantage?
Answer:

1. If all the first terminals of all the devices are connected to one point and all the second terminals are connected to another point such type of connection is called parallel connection.
2. In parallel connection electricity has more than one path.
3. Even if any one of them is removed the circuit remains closed.

Question 11.
How does the brightness of the bulb changes, if a number of cells are connected 0 in series ii) in parallel?
Answer:
i) If a number of cells are connected in series the brightness of the bulb is enhanced,
ii) If a number of cells are connected in parallel the brightness of the bulb remains same (or) does not change.

Question 12.
Why the batteries in a torch light are connected in series?
Answer:

1. If we connect batteries/cells in series it enhance the brightness of the bulb, the batteries in a torch light are connected in series.
2. So, to enhance the brightness of the bulb.

Question 13.
How does the brightness of the bulb change when a number of bulbs are connected in i) series ii) parallel?
Answer:
i) If a number of bulbs are connected in series the brightness of the bulb is reduced.

ii) If the number of bulbs are connected in parallel, the brightness of the bulb remains same.

Question 14.
How does an electric-iron box work?
Answer:

1. The electric iron box contain a coil of wire, which is generally made up of Nichrofne.
2. This coil of wire is called a filament, which produce heat, when current is passed through it.

Question 15.
How does a bulb with filament glow?
Answer:

1. When electric current is passed through the filament (made with Tungsten), it becomes red hot and further becomes bright white.
2. This bright white glow of the filament gives light.

Question 16.
What happens if we pass current through the copper coil around a nail?
Answer:
The nail acts as a magnet, when current is passed through the coil around it.

Question 17.
Are electro-magnets permanent magnets? Justify your answer.
Answer:

1. Electromagnets are not permanent magnets.
2. Because, they lose the property of magnetism when the circuit is open.

Question 18.
Write some situations which lead to an electric shock.
Answer:

1. Operating a switch with a wet hand.
2. Removing plug pins when the switch is on.
3. Using wires without insulation.
4. Changing bulb when the switch is on.
5. Holding a person with a current shock.

Question 19.
What immediate action should we take to save a person who gets electric shock?
Answer:

1. When anybody gets an electric shock.
2. First, cut off the power supply.
3. If it is not possible, push away the person with a dry stick.
4. If the shock is severe and the person is unconscious, give mouth to mouth artificial respiration.
5. Sometimes heart beat ceases, at that time keep your palms on his chest and press down and release until the heartbeat is recovered. This is called Cardio Pulmonary Resuscitation (CPR). Immediately take him to the hospital.

Question 20.
What is ISI? What is its use?
Answer:

1. ISI means Indian Standards Institution.
2. It can be observed on the electrical devices.
3. The ISI mark ensures the quality of appliances and safety of users.

Question 21.
When the power to house cut off, the Saritha noticed that her father was changing the fuse wire. Then she had many doubts. What would be those doubts?
Answer:

1. What is fuse?
2. How does it work?
3. What happens to the fuse, when current is cut off?
4. What is the use of fuse?

Question 22.
Filament bulbs are hot, but some other bulbs like LED, CFL are cold. Guess, what is the reason?
Answer:

1. Filament bulbs are made up of Tungsten filaments.
2. These are working on the principle of heating effect of the electricity.
3. So, they are hot.
4. But, other bulbs like CFL and LED are not working on this principle. Hence they are cool.

Question 23.
Guess, what would happen if home appliances were connected in a series connection?
Answer:

1. If one device is stopped or failed to work, all other devices will also stop.
2. If one device is switched on the other devices will also works.

Question 24.
Write the procedure of making of our own cell.
Answer:

1. Take a lemon and insert a zinc plate and a copper plate into it.
2. These plates acts as electrodes and the juice inside the fruit acts as electrolyte.
3. Connect two terminals of the bulb to zinc and copper plates using connecting wires.
4. The bulb will glow.

Question 25.
Write the required materials to do an activity to know about heating effect of electric current.
Answer:

1. Electric cell,
2. Iron nails – 2,
3. Wooden board,
4. Connecting wires,
5. 10 cm of Nichrome wire etc.

Question 26.
Write the material required to make a electromagnet.
Answer:
Battery, Switch, Iron nail, Insulated copper wire, and small pins.

Question 27.
What happens if the switch is open in the experiment of given picture.

Answer:
When we switched off the circuit, immediately all the pins fall from the iron nail.

Question 28.
Observe the diagram and write answers to the given questions.

1) Which bulb is more power saver?
2) Which bulb has less life span?
3) Which bulb do you suggest for your home?
4) Which bulb works on the principle of heating effect of electricity?
Answer:

1. LED
2. Incandescent
3. LED
4. Incandescent.

Question 29.
Fill in the table with suitable answers.

Name of the Device	Use
	To give light
Switch
	To protect from high voltage
Cell

Answer:

Name of the Device	Use
Bulb	To give light
Switch	To open or close a circuit
Fuse	To protect from high voltage
Cell	To given electricity

Question 30.
Observe the following circuit diagrams and answer the question.

What difference do you find between diagrams A and B?
Answer:
We observe that the bulb in circuit A is not glowing and in circuit B it is glowing.

We can also see the switch is in OFF mode in circuit diagram A and it is in ON mode in circuit diagram B. Circuit diagram A represents open circuit, where as circuit diagram B represents closed circuit.

Question 31.
Observe the figure and give answers to the questions.
1) How are the cells connected?
2) If one of the cells is disconnected what will happen?

Answer:

1. Cells are connected in parallel.
2. The bulb will glow as usual if one of the cells is disconnected.

Question 32.
Draw the given diagram by using symbols instead of realistic components.
Answer:

Question 33.
Draw the diagram of setup of material in make a cell with lemon.
Answer:

Question 34.
Draw the diagram of a simple circuit.
Answer:

Question 35.
Draw a circuit diagram showing the parallel connection of the cells.
Answer:

Question 36.
Draw a circuit diagram showing the series connection of the cells.
Answer:

37. Draw a circuit diagram showing the parallel connection of bulbs.
Answer:

38. Draw a circuit diagram showing the series connection of bulbs.
Answer:

39. Draw a device alignment diagram of equipment in the experiment of heating effect of electric current.
Answer:

40. Draw the diagram showing the arrangement of circuit to make an electromagnet.
Answer:

41. Draw the symbol of ISI mark.
Answer:

42. Where do we use dry cells? What are its advantages?
Answer:

1. In our daily life we use dry cells in torch lights, wall clocks, radios etc.
2. Dry cell consists of an electrolyte in dried form.
3. So, it is easy to move anywhere.

Question 43.
How does a switch work in a circuit?
Answer:

1. We know that switch Is used to open or dose a circuit
2. When the switch is ‘off’ position, bulb does not glow, because the circuit Is opened.
3. If we keep the switch in ‘on’ mode, the circuit is closed and the bulb glows.

Question 44.
How do circuit diagrams help to electricians?
Answer:

1. A circuit diagrams is a graphic representation of an electric circuit
2. It shows how the electric components are connected together.
3. Electricians and engineers draw circuit diagrams to help them design the actual circuits.

Question 45.
What is the first aM few electric shock?
(OR)
How do you perform CPR?
Answer:

1. It the electric shock is severe and the person is unconscious, given mouth to mouth artificial respiration.
2. Sometimes heartbeat ceases, at that time keep your palms on his chest and press down and release until the heartbeat is recovered, this is called Cardio Pulmonary Resuscitalion (CPR)

Question 46.
How do you check for the good electric appliances?
Answer:
While selecting electric appliances:

1. Check ISI (Indian Standard institution) mark on all electrical appliances before you buy.
2. Check for more star rating.

7th Class Science 6th Lesson Electricity Long Questions and Answers

Question 1.
What is a cell? How does it work?
Answer:
A cell is a device used to generate electricity. It mainly consists of two components.

1. Electrolyte – This is a chemical component that conducts the electricity.
2. Electrodes – There are two electrodes in a ceiL One is positive electrode called anode and the other is negative electrode called cathode.

When electrodes come in contact with electrolyte, a chemical reaction takes place inside the cell to produce electricity. Thus, it converts the chemical energy into electrical energy When electrodes are connected to the wires in a circuit, electricity passes through them.

Question 2.
What is a both? Write different types of bain How does an Incandescent bulb work? Does if save Are electrical energy?
Answer:

1. Bulb is an electric device which converts electrical energy into light energy.
2. There are different types at bulbs. They are 1) incandescent bulb, 2) Fluorescent bulb (Tube light), 3) CFL (Compact Fluorescent Lamp), 4) LED bulb, etc.
3. Incandescent bulb works on the principle of heating effect of electricity.
4. Incandescent bulb doesn’t save electrical energy. It consumes more electrical energy compared to CFL and LED lamps.

Question 3.
Write the differences between series and parallel connections of cells.
Answer:

Series connection	Parrllel connection
I) If the second terminal of the first device is connected to the first end of the second device such type of  connection is called series connection.	1) If all the first terminals of all the devices are connected to one point and all the second terminals are cennected to another point, such type of connection is called of parallel connection.
2) In series connection, electricity has only one path.	2) In parallel connection electricity has more than one path.
3) If any one of the cells is removed or not functioning properly it becomes an open circuit.	3) Even if anyone of them is removed the circuit remains closed.
4) In series brightness of the bulb is enhanced.	4) In parallel connection bulb will glow as usual.
5) We can use series connection of cells in torch lights, toys, remotes, wall clocks etc.	5) We can use parallel connection of cells for a long lasting battery life.

Question 4.
Write the differences between series and parallel connections of bulbs.
Answer:

Series connection of bulbs	Parallel connections of bulbs
1) In series connection electricity has only one path.	1) In parallel connection electricity has more than one path.
2) If one of the bulbs is removed or broken, the circuit becomes open, and the otter bulbs will not glow.	2) If one of tie bulbs is removed or broken, the circuit remains same and the busib will j glow as usual.
3) The brightness of the bciib is reduced in series connection.	3) The brightness erf the bulb remains same in parallel connection.
4) Series eettnectioo of btsifes is used for decorative purpose.	4) FaraEei coaraeetkm of bulbs is used in household connection.

Question 5.
Explain the following :
a) Heating effects of electric current.
b) Magnetic effects of electric current.
Answer:
a) Heating effects of electric current:

1. The production of heart due to the flow of electricity through a wire is called heating effects of electricity.
2. Electric devices like electric stoves, room heaters, iron boxes, electric kettles, electric cookers, heaters, geysers, hair dryers work on the principle of heating effects of electric current.
3. All these appliances contain a heating element is called a filament.
4. Generally, a filament is made up of Nichrome in iron boxes and the filaments of an electric bulb is made of Tungsten.

b) Magnetic effects of electric current:

1. The production of magnetic force due to the flow of electricity through a wire is called magnetic effect of electricity.
2. The devices which act as magnets when electricity passes through them are called electromagnets.
3. The electric devices like loudspeakers, fan, bell, motor, mixer grinders, MRI machines, generators, metal detectors, mobile phones work on the principle of magnetic effect of electricity.
4. Magnetic effects produced in a coil which is wound around a soft iron due to the passing of electricity in the coil.

Question 6.
1) What is an electric shock?
2) Which situations lead to an electric shock?
3) What is the first aid for efectric shock?
4) How does CPR help to the person?
Answer:
1) An electric shock occurs when a person comes into contact with an electrical source. Electricity flows through a portion of the body causing a shock It leads to major damage, sometimes it may cause death.

2) i) Operating a switch with a wet hand.
ii) Removing plug pins when the switch is on.
iii) Using wires without insulation.
iv) Changing bulb when the switch is on.

3) i) When anybody gets an electric shock.
ii) First, cut off the power supply.
iii) If it is not possible, push away the person with a dry stick.
iv) If the shock is severe and the person is unconscious, give mouth-to-mouth artificial respiration.

4) Sometimes heart beat ceases, at that time keep your palms on his chest and press down and release until the heartbeat is recovered. This is called Cardio Pulmonary Resuscitation (CPR). Immediately take him to the hospital.

Question 7.
Fill in the table with suitable answers.

Answer:

Question 8.
Observe the given figures and answer the following questions.
Answer:

1) In which circuit bulbs are connected in parallel?
2) In which circuit electricity passes through only one path?
3) Which circuit represents household connections?
4) What happens if one bulb is damaged in circuit A?
5) In which circuit glow of bulb is enhanced?
Answer:

1. Circuit B
2. Circuit A
3. Circuit B
4. Circuit will be opened
5. Circuit A

Question 9.
Fill in the table.

Name of the device	Magnetic effect of electricity	Heating effect of electricity
1. Electric stove	✗	✓
2. Electric iron box
3. Electric fan
4. Electric bell
5. Metal detector
6. Loud speaker
7. Filament bulb
8. Electric kettle
9. Geyser

Answer:

Name of the device	Magnetic effect of electricity	Heating effect of electricity
1. Electric stove	✗	✓
2. Electric iron box	✗	✓
3. Electric fan	✓	✗
4. Electric bell	✓	✗
5. Metal detector	✓	✗
6. Loud speaker	✓	✗
7. Filament bulb	✗	✓
8. Electric kettle	✗	✓
9. Geyser	✗	✓

Question 10.
Draw the diagram of a dry cell and label the parts.
Answer:

Question 11.
Draw the symbols of given electrical components.
1) Cell 2) Battery 3) Bulb 4) Glowing bulb 5) Switch in ‘ON’ mode 6) Switch in ‘OFF’ mode 7) Fuse 8) Connecting wires.
Answer:

Question 12.
Here a circuit with real components are given. Draw the circuit by using symbols of the components.
Answer:

Answer:

Question 13.
Kalyan uses 5 LED bulbs of 9W for 10 hours, 3 fans of 60 W for 8 hours, 1 TV of 100 W for 6 hours in his house per day. Calculate the cost of his consumed electricity for a month at the rate of ₹ 10 per unit.
Answer:

Problems Given In The Lesson

Exercise – 1

The meter reading in Chandu’s house for the month of December 2020 is 29171 units. The meter reading in the previous month is 29062 units. Calculate how much he has to pay towards electricity bill in December. The unit cost is Rs.3.16.
Answer:

Reading in December	29171 units
Reading in previous month	29062 units
No. of units of electricity consumed	109 units
Cost per unit	Rs.3.16
Amount to be paid	109 x 3.16= Rs.344.44 ( Rs.344 only)

Exercise – 2

Suppose in a house there are 5 bulbs of 100W each, five of 60 W each, five of 40W each. All of them are used for five hours everyday. How many units of electricity is used in the month of February 2021? How much will they have to pay at Rs.2.80/- per unit?
Answer:

AP Board 7th Class Science 6th Lesson 1 Mark Bits Questions and Answers Electricity

I. Multiple Choice Questions

1. The positive electrode in a cell is called
A) Electrolyte
B) Anode
C) Cathode
D) Filament
Answer:
B) Anode

2. Which of the following converts chemical energy into electrical energy?
A) Cell
B) Bulb
C) Fan
D) Switch
Answer:
A) Cell

3. The container of a dry cell works as
A) Anode
B) Cathode
C) Electrolyte
D) None
Answer:
B) Cathode

4. A carbon rod with a metal cap in a cell works as
A) Anode
B) Cathode
C) Electrolyte
D) None
Answer:
A) Anode

5. Generally the chemical used in a dry cell is
A) Copper sulphate
B) Sodium chloride
C) Ammonium chloride
D) Potassium hydride
Answer:
C) Ammonium chloride

6. The lemon juice in a cell is acts as a
A) Anode
B) Cathode
C) Electrolyte
D) None
Answer:
C) Electrolyte

7. Dry cell is not used in
A) Torch light
B) Wall clock
C) Radio
D) Mobiles
Answer:
D) Mobiles

8. Assertion (A) : Dry cell is easy to move any where.
Reason (R) : Dry cell consists of also electrolyte in dried form.
A) A and R are correct and R is a correct reason to A
B) A and R are correct but R is not a correct reason to A
C) A is correct but R is incorrect
D) A is incorrect but R is correct
Answer:
A) A and R are correct and R is a correct reason to A

9. Generally, button cells are used in
A) Torch lights
B) Mobile phones
C) Wrist watches
D) Vehicles
Answer:
C) Wrist watches

10. 1) When switch is in ‘off position the circuit is a closed.
2) When switch is in’off position the bulb does not glow.
A) 1 is correct
B) 2 is correct
C) 1 and 2 are correct
D) 1 and 2 are wrong
Answer:
B) 2 is correct

11. Which of the following consumes more power than others?
A) Incandescent bulb
B) Fluorescent bulb
C) CFL
D) LED
Answer:
A) Incandescent bulb

12. Fuse wire is made of
A) Low melting point wire
B) High melting point wire
C) No melting point wire
D) A or B
Answer:
A) Low melting point wire

13. Which of the follow device prodect the electrical home appliances?
A) Fuse
B) MCB
C) A and B
D) Filament
Answer:
C) A and B

14. A siaifsie decftfc circuit amwBlmg of
A) a battery
B) a bulb
C) a switch
D) above all
Answer:
D) above all

15. This is the symbol of
A) a cell
B) a battery
C) two switches
D) fuse
Answer:
B) a battery

16. This symbol represents
A) a cell
B) an open switch
C) a closed switch
D) an open cell
Answer:
B) an open switch

17. WMADftefofloif mg represents a glowing bulb?

Answer:
A

18. On series connection has
A) Only two paths
B) Only one path
C) More than one path
D) None
Answer:
B) Only one path

19. If a number of cells are connected in series the brightness of the bulb is
A) Enhanced
B) Reduced
C) As usual
D) A or B
Answer:
A) Enhanced

20. If a number of cells are connected in parallel the brightness of the bulb is
A) Enhanced
B) Reduced
C) As usual
D) A or B
Answer:
C) As usual

21. In which connection one of the cells are removed the circuit does not open?
A) Series
B) Parallel
C) A and B
D) None
Answer:
B) Parallel

22. If a number of bulbs are connected in series the brightness of the bulb is
A) Enhanced
B) Reduced
C) Sanafe issmre
D) Aor B
Answer:
B) Reduced

23. If a number of bulbs are connected in parallel the brightness of the bulb is
A) Enhanced
B) Reduced
C) Remains same
D)A or B
Answer:
C) Remains same

24. Household devices are connected in
A) Series
B) Parallel
C) A or B
D) None
Answer:
B) Parallel

25. Which of the following gives light by glowing in Bulbs?
A) Nichrome
B) Tungsten
C) Alnico
D) Copper
Answer:
B) Tungsten

26. Generally filament in iron boxes are made up of
A) Nichrome
B) Tungsten
C) Alnico
D) Copper
Answer:
A) Nichrome

27. The devices which acts as magnets when electricity passes through them
A) Electric kettles
B) Electric heaters
C) Electromagnets
D) MCB
Answer:
C) Electromagnets

28. Which of the following works on principle of magnetic effect of electricity?
A) Electric rice cooker
B) Thermometer
C) Electric bell
D) Electric bulb
Answer:
C) Electric bell

29. Which of the following is required to make an electromagnet?
A) Coiled copper wire
B) Nail
C) Electricity
D) Above all
Answer:
D) Above all

30. Which of the following property can levitate a magnetic object?
A) Heat effect of electricity
B) light effect of electricity
C) Chemical effect of electricity
D) Magnetic effect erf etedtricity
Answer:
D) Magnetic effect erf etedtricity

31. Electromagnets are
A) permanent magnets
B) temporary msassets
C) not the magnets
D) bad conductors
Answer:
A) permanent magnets

32. 1 kilo watt =
A) 1000 watts
B) 100 watts
C) 1/1000 watts
D) 1/100 watts
Answer:
A) 1000 watts

33. 1 unit of electricity means
A) 1 WH
B) 1 KWH
C) 1000 KWH
D) 1/1000 KWH
Answer:
B) 1 KWH

34. Immediate action to be tacken when an electric shock occurs is
A) pouring erf water
B) danger with the device
C) Cut off power supply
D) Expiry date of the device
Answer:
C) Cut off power supply

35. Indicates
A) Power saving erf the device
B) Danger with the device
C) Quality erf the device
D) Expiry date of the device
Answer:
C) Quality erf the device

II. Fill in the blanks

1. …………………. is a device used to generate electricity
2. The chemical componesrf that conducts electricity is called …………………. .
3. The negative electrode is called …………………. .
4. The …………………. electrode is called anode.
5. A cell converts the …………………. energy into …………………. energy.
6. The positive and negative terminals are called …………………. .
7. A group of …………………. is called a battery.
8. When switch is in ‘ON’ mode, the circuit is …………………. .
9. An ordinary bulb gives …………………. and …………………. .
10. CFL means …………………. .
11. LED means …………………. .
12. The electrical appliance with more stars consumes …………………. electricity.
13. …………………. protects home appliances from the excess of electricity flows through them.
14. Generally, fuse wire made of …………………. melting point.
15. MCB means …………………. .
16. …………………. is better, when compared to electric fuse.
17. A …………………. is a graphical representation of an electrical circuit.
18. The electrical symbol of fuse is …………………. .
19. In …………………. connection of cells life of battery increases.
20. Nichrome wire gets …………………. when electricity passed through it.
21. The production of …………………. due to the flow of electricity through a wire is called heating effect of electricity.
22. Household electricity is measured in …………………. .
23. 1 …………………. = 1000 watts.
24. KWH means …………………. .
25. A …………………. occurs when a person comes into contact with an electrical source.
26. Electricity flows through a portion of the body causing a
27. CPR means …………………. .
28. ISI means …………………. .
29. ISI mark ensures …………………. of the appliances.
Answer:

1. A cell
2. Electrolyte
3. Cathode
4. positive
5. chemical, electrical
6. electrodes
7. cells
8. closed
9. heat, light
10. Compact Fluorescent Lamp
11. Light Emitting Diode
12. less
13. Fuse
14. Low
15. Miniature Circuit Breaker
16. MCB
17. circuit diagram
18. 
19. parallel
20. heated up
21. heat
22. KWH or units
23. kilo watt
24. kilo watt hour
25. Electric
26. shock
27. Cardio Pulmonary Resuscitation
28. Indian Standards Institutions
29. quality

III. Match the following

1.

Group – A	Group – B
A) Electrolyte	1) Copper
B) Electrode	2) Nichrome
C) Filament	3) Ammonium chloride
D) Connecting wire	4) Carbon rod
E) Cell	5) Lithium – ion

Answer:

Group – A	Group – B
A) Electrolyte	3) Ammonium chloride
B) Electrode	4) Carbon rod
C) Filament	2) Nichrome
D) Connecting wire	1) Copper
E) Cell	5) Lithium – ion

2.

Group – A	Group – B
A) Dry cell	1) Bikes
B) Lithium cell	2) Wrist watches
C) Button cell	3) Torches
D) Alkaline cell	4) Mobiles

Answer:

Group – A	Group – B
A) Dry cell	3) Torches
B) Lithium cell	4) Mobiles
C) Button cell	2) Wrist watches
D) Alkaline cell	1) Bikes

3.

Group – A	Group – B
A) Cell	1) Protects home appliances
B) Bulb	2) Opens or closes circuits
C) Fuse	3) Produces light
D) Switch	4) Produces electricity
E) Iron box	5) Produces heat
F) Cranes	6) Produce magnetism

Answer:

Group – A	Group – B
A) Cell	4) Produces electricity
B) Bulb	3) Produces light
C) Fuse	1) Protects home appliances
D) Switch	2) Opens or closes circuits
E) Iron box	5) Produces heat
F) Cranes	6) Produce magnetism

4.

Answer:
A – 7, B – 3, C – 1, D – 5, E – 6, F – 2, G – 4.

Do You Know?

→ In 1752, Franklin conducted the kite experiment to show that lightning was also electricity. He flew a kite during a thunderstorm. He tied a metal key to the string of the kite to conduct the electricity.

→ LED (Light Emitting Device) has two legs. Long leg indicates positive(+ve) and short leg indicates negative (-ve). Early LEDs produced only red light, but modern LEDs can produce several different colors, including red, green and blue light. LEDs are used as indicators in mobiles, laptops, T.V remotes etc.

→ A switch can be placed anywhere in the circuit and a cell can be connected in any direction in the electric circuit.

→ The scientist Oersted discovered that a magnetic field is produced around a current carrying conductor. Electromagnets are made by using the relationship between electricity and magnetism.

→ Michael Faraday made a magnet to revolve around a coil of wire which produced electricity. He invented electric generator or dynamo and transformer.

These AP 7th Class Science Important Questions 5th Lesson Motion and Time will help students prepare well for the exams.

AP Board 7th Class Science 5th Lesson Important Questions and Answers Motion and Time

Question 1.
When can you say that an object is in motion?
Answer:
An object is said to be in motion if it changes its position with respect to its surroundings.

Question 2.
When can you say that an object is at rest?
Answer:
An object is said to be at rest if there’ is no change in its position with respect to its surroundings.

Question 3.
What is distance?
Answer:
The total length of the path travelled by an object between two places is called distance.

Question 4.
What are the units for distance?
Answer:
The basic unit of distance is centimeter (cm). S.I units of distance is metre. But kilometre is used to measure large distances.

Question 5.
What is displacement?
Answer:
The change in position of an object is called displacement. It is the shortest distance between the starting and final positions.

Question 6.
What is time?
Answer:
The measurable period between two incidents (events) is called time.

Question 7.
What are the units of time?
Answer:
The basic unit of time is second (s). Larger units of time are minutes (min) and hours (h).

Question 8.
How do we measure or estimate time?
Answer:
We can measure or estimate time using clocks or watches.

Question 9.
What is translator motion? Give examples.
Answer:
If all points of a moving object move through the same distance in same direction, then the motion is said to be translatory motion. Ex: Coconut falling from a tree, movement of lift, car travelling on a straight road etc.

Question 10.
What is rotatory motion? Give examples.
Answer:
If all the parts of a moving body follow a curved path with respect to a fixed centre or axis of rotation, it is said to be in rotatory motion.
Ex: motion of merry-go-round, top, fan

Question 11.
What is axis of rotation?
Answer:
The imaginary line passing through the fixed centre around which the parts of the objects move in a curved path during rotatory motion is called axis of rotation.

Question 12.
What is circulatory motion?
Answer:
Circular motion is a special type of rotatory motion, where the distance between’the object and the axis of rotation remains fixed.

Question 13.
How does the see – saw move? What kind of motion is this?
Answer:
See-saw moves in up and down direction with a fixed point. This type of motion is called oscillatory motion or vibratory motion.

Question 14.
How does the needle of swing machine moves? What type of motion is this?
Answer:
Needle of swing machine moves in up and down direction with a fixed point. This type of motion is called oscillatory motion or vibratory motion.

Question 15.
What is oscillatory motion? Give examples.
Answer:
The ‘to and fro’ motion of an object about a fixed point that always following the same path is called oscillatory or vibratory motion.
Ex: motions in swing, strings of veena, needle of sewing machine etc.,

Question 16.
What is uniform motion?
Answer:
If a body covers equal distances in equal intervals of time, it is said to be in uniform motion.

Question 17.
What is non-uniform motion?
Answer:
If a body covers unequal distances in equal intervals of time, it is said to be in nonuniform motion.

Question 18.
What is speed?
Answer:
Speed of an object can be defined as the distance travelled by it in a unit time.

Question 19.
What are the units for speed?
Answer:
Units of speed is meter per second (m/s) or kilometre per hour (Km/h).
1 Km / h = 5/18 m/s

Question 20.
Which components are taken on which axis in a distance-time graph?
Answer:
Distance is usually plotted along Y-axis or the vertical axis, while time is usually plotted along X-axis or the horizontal axis.

Question 21.
What can we find from the distance-time graph?
Answer:
From the distance-time graph, we can find the speed of object.

Question 22.
Which Indian organization working for launching of rockets?
Answer:
Indian Space Research Organization (1SRO) is working for launching of rockets in our country.

Question 23.
Expand ISRO.
Answer:
Indian Space Research Organization.

Question 24.
Where do the rockets are launched from?
Answer:
Rockets are being launched from Rocket launching stations such as Satish Dhawan Space Centre (SDSC – SHAR)

Question 25.
What is INSAT? For what purpose does ISRO maintaining it?
Answer:
INSAT (Indian National Satellite System) is one of the largest communication satellites being maintained by ISRO. It is being maintained by ISRO for fast and reliable communication.

Question 26.
What is the satellite being maintained by ISRO for earth observation?
Answer:
Remote sensing IRS satellite is being maintained by ISRO for earth observation.

Question 27.
What is the world record created by ISRO?
Answer:
On 15th February 2017, ISRO launched 104 satellites in a single rocket, it is a world record.

Question 28.
Expand SDSC.
Answer:
Satish Dhawan Space Centre

Question 29.
Expand SHAR.
Answer:
Sriharikota High Altitude Range

Question 30.
Where do SDSC- SHAR located?
Answer:
Satish Dhawan Space Centre (SDSC – SHAR) is located in Sriharikota, SPSR Nellore district of Andhra Pradesh. It is the Spaceport of India.

Question 31.
What are artificial satellites?
Answer:
An artificial satellite is a man made object, launched to revolve around the earth.

7th Class Science 5th Lesson Motion and Time Short Questions and Answers

Question 1.
How do you decide whether any object is in motion or at rest?
Answer:

1. We can decide whether any object is in motion or at rest by observing its position with respect to its surroundings.
2. If an object is not changing its position with respect to the surroundings then we can say that the object is in rest.
3. We can say an object is in motion when it is changing its position with respect to the surroundings.

Question 2.
Write the differences between distance and displacement.
Answer:

Distance	Displacement
1. The total length of the path travelled by an object between two places is called distance.	1. It is the shortest distance between the starting and final positions of a moving object.
2. It depends upon the path. It changes according to the path taken.	2. It does not depend upon the path and it only depends upon the initial and final position of the body.
3. It can be measured along the path. No matter whether it’s a straight or a non-straight path.	3. It can only be measured along a straight path no matter what the path followed by object.
4. To calculate it, the direction is not considered. So it does not depend on direction	4. To calculate it, the direction is taken into consideration. So it depend on direction.
5. Its value never become Zero.	5. Its value may become Zero.
6. Its value is always more than or equal to the value of displacement.	6. Its value is always less than or equal to the value of distance.

Question 3.
How are stop watches useful to us?
Answer:

1. We use stop clocks in the laboratory to measure time taken for completion of chemical reactions, time taken by the pendulum for one oscillation etc.
2. Apart from this, they also help us to measure the time in races and games very accurately even to the extent of fraction of seconds.
3. Now-a-days, we use electronic clocks, digital clocks, and stop clocks in mobile phones to measure time.
4. Stop clocks are used to measure shorter time intervals between two events accurately.

Question 4.
What is translatory motion? Explain different types of translatory motions?
Answer:

1. If all points of a moving object move through the same distance in same direction, then the motion is said to be translatory motion.
2. Translatory motions are of two types. 1) Rectilinear motion and 2) Curvilinear motion.
3. If a body in translatory motion moves along a straight line then the motion is called rectilinear motion. Light rays from the sun moves in straight line path. Hence, the motion of light rays is rectilinear motion.
4. If a body in translatory motion move along a curved path then the motion is called cur vilinear motion. The movement of body of snake is in curvilinear motion.

5. How the units for time are related to one another?
Answer:
Units for time are related to one another in the following way

Question 6.
What is rotatory motion? Explain with a example.
Answer:

1. If all the parts of a moving body follow a curved path with respect to a fixed centre or axis of rotation, it is said to be in rotatory motion.
2. Let us understand the rotatory motion of merry-go-round.
3. While it is moving, persons sitting on hanging chairs like toys move in a curved path around a fixed centre.
4. The imaginary line passing through the fixed centre is called axis of rotation.
5. All the parts of the objects move in a curved path with respect to this fixed centre or a fixed axis. This type of motion is known as Rotatory Motion.

Question 7.
Which similarity do you find in strings of veena and needle of sewing machine?
Answer:

1. The strings of veena and needle of sewing machine are moving in ‘to and fro’ motion or back and forth motion.
2. The direction of motion of the objects changes alternatively along the same path about a fixed point.
3. Hence, we can say that they are in oscillatory motion or vibratory motion.

Question 8.
Write the differences between uniform and non-uniform motions.
Answer:

Uniform motion	Non-uniform motion
1. If a body covers equal distances in equal intervals of time, it is said to be in uniform motion.	1. If a body covers unequal distances in equal intervals of time, it is said to be in non-uniform motion.
2. Speed at all points of time is equal. Ex: Movement of minutes hand in a wallclock	2. Speed changes from time to time. Ex: Movement of butterfly in the garden

Question 9.
Do you find any relation between distance and time?
Answer:

1. The relation between distance and time can be understand in terms of speed.
2. The distance travelled by an object in a unit time is called as speed.
3. If an object takes less time to cover more distance, the speed will be more.
4. If an object takes more time to cover less distance, the speed will be less.

Question 10.
What is average speed? How to calculate the average speed?
Answer:

1. Average speed is the ratio of total distance covered and total time taken by the body to cover the distance.
2. It can be calculated using the formula…
   Average speed = Total distance travelled /Total time taken to travel

Question 11.
How does a rocket move?
Answer:

1. If you let the air out of an inflated balloon, the air comes out of balloon in one direction and the balloon moves on the opposite direction with the same speed.
2. Rockets also works in the same way, exhaust gases coming out of the engine’s nozzle at the high speed push the rocket forward.Thus the rocket moves.

Question 12.
What are the major rocket systems used to send the satellites by ISRO?
Answer:
The major rocket systems used to send the satellites by ISRO are:

1. SLV (Satellite Launch Vehicle),
2. ASLV (Augmented Satellite Launch Vehicle),
3. PSLV (Polar Satellite Launch Vehicle),
4. GSLV (Geosynchronous Satellite Launch Vehicle) and GSLV Mark III

Question 13.
What are rockets? Why are they used?
Answer:

1. Rockets are devices thal: produce force or push needed to move an object forward.
2. Rockets are used to launch space crafts and satellites.
3. They are also used to shoot missiles.

Question 14.
Is there any similarity between movements of rocket cracker and real rocket?
Answer:

1. Motion of the actual rocket is similar to motion of the rocket cracker.
2. When rocket cracker fired, exhaust gases coming out of it push the rocket cracker forward.
3. Similarly when fuel in real rocket ignited, exhaust gases coming out of the engine’s nozzle at the high speed push the rocket forward.

Question 15.
What are artificial satellites? Mention different types of satellites.
Answer:

1. An artificial satellite is a manmade object, launched to revolve around the earth.
2. The size, altitude and design of a satellite depends on its purpose.
3. Navigation satellites, communication satellites, weather satellites, earth observa- . tion satellites, astronomical satellites, Space stations are different types of artificial satellites.

Question16.
How do scientists prepare weather report in advance?
Answer:

1. Scientists can prepare weather report in advance with the help of artificial satellites.
2. They study the earth’s atmosphere with the help of artificial satellites.
3. They analyse the data provided by the satellites to estimate the components of weather such as rainfall, temperature, Humidity etc.
4. They can observe the occurrence of cyclones, and their movement very keenly with the help of photographs and other data provided by satellites.
5. Thus they can prepare weather reports in advance.

7th Class Science 5th Lesson Motion and Time Long Questions and Answers

Question 1.
What is motion? Explain different types of motions?
Answer:

1. Motion is a state of an object in which it is changing its position with respect to its surroundings.
2. Motion is of three types: 1. Translatory motion 2. Rotatory motion 3. Oscillatory motion.
3. If all points of a moving object move through the same distance in same direction, then the motion is said to be translatory motion.
   Ex : Coconut falling from a tree, movement of lift, car travelling on a straight road etc.
4. Translatory motion is again of two types, i) rectilinear motion and ii) curvilinear motion.
5. If a body in translatory motion moves along a straight line then the motion is called rectilinear motion.
   Ex: Light rays from the sun ‘
6. If a body in translatory motion move along a curved path then the motion is called curvilinear motion.
   Ex: The movement of snake body
7. If all the parts of a moving body follow a curved path with respect to a fixed centre or axis of rotation, it is said to be in rotatory motion. Ex: motion of merry-go-round, top, fan
8. The ‘to and fro’ motion of an object about a fixed point that always following the same path is called oscillatory or vibratory motion.
   Ex: motions in swing, strings of veena, needle of sewing machine etc.,.

Question 2.
How do our ancestors used to estimate time?
Answer:

1. Like minutes and hours, week, fortnight, month, season, Ayana are also units for measuring time. _
2. Sundial, sand clock, water clock etc., are used primitively to measure the time.
3. Our ancestors noticed that many events in nature repeat themselves after definite intervals of time.
4. The time between one sunrise and the next was called a day.
5. Similarly, a month was measured from one new moon to the next.
6. A year was fixed as the time taken by the earth to complete one revolution around the sun.
7. A mean solar day contains 24 hours.

Question 3.
Explain uniform and non-uniform motions with example.
Answer:

1. “If a body covers equal distances in equal intervals of time, it is said to be in uniform motion.”
   “If a body covers unequal distances in equal intervals of time, it is said to be in non-uniform motion.”
2. Observe the movement of hands in a wall clock and the movement of a butterfly in a garden.
3. Measure the angle between two successive positions of the minute hand in a wall clock.
4. You can observe that the change in its position is same for every minute.
5. But in the case of the butterfly, the change in its position is not constant while it is . flying from one flower to another in the garden.
6. We understand that the minutes hand in wall clock covers equal distances in equal intervals of time and the butterfly covers unequal distances in equal intervals of time.
7. Hence we can say that the minutes hand in a wall clock has uniform motion and the butterfly has non-uniform motion.

Question 4.
Write a short note on Indian Space Research Organization (1SRO).
Answer:

1. With the visionary of Dr. Vikram Sarabhai, Indian Space Research Organization, formed in 1969.
2. Dr. K Sivan is the present chairman of ISRO.
3. Throughout the years, ISRO has upheld its mission of bringing space technology to the service of the common man.
4. In the process it has become one of the six largest space agencies in the world.
5. ISRO maintains one of the largest communication satellites INSAT and remote sens-ing IRS satellites for fast and reliable communication and earth observation.
6. SLV (Satellite Launch Vehicle), ASLV (Augmented Satellite Launch Vehicle), PSLV (Polar Satellite Launch Vehicle), GSLV (Geosynchronous Satellite Launch Vehicle), GSLV Mark III are the major rocket systems used to send the satellites by ISRO.
7. On 18th June 2016 ISRO launched 20 satellites in a single vehicle.
8. On 15th February 2017 ISRO launched 104 satellites in a single rocket, it is a world record.

Question 5.
Write a short notes on Satish Dhawan Space Centre (SDSC) – SHAR.
Answer:

1. The Space Centre, which was popularly known as SHAR (Sriharikota High Altitude Range) was renamed as Satish Dhawan Space Centre SHAR on September 5, 2002, in the memory of Prof. Satish Dhawan, former Chairman of ISRO.
2. It is an island of technological excellence where in nature co-exists with the techno-crats.
3. Satish Dhawan Space Centre (SDSC – SHAR) is located in Sriharikota, SPSR Nellore, district of Andhra Pradesh.
4. It is the Spaceport of India. It is one of the main centers of Indian Space Research Organization (ISRO), Department of Space (DOS), Government of India.
5. This Centre provides world class launch base infrastructure for different launch
   vehicle/ satellite missions for remote sensing, communication, navigation & scientific purposes.
6. It is one among the best-known names of the Spaceports of the world today.

Question 6.
What is artificial satellite? Write some applications of satellite in our daily life.
Answer:
An artificial satellite is a man made object, launched to revolve around the Earth.
There are several applications of satellites in our daily life. Among them some important are…

1. Communication – the geostationary satellites are used for communication purposes like long distance telephone calls, interrnet and television broadcasting etc.
2. Collecting information about space and planets.
3. Collection of information about natural resources of earth.
4. Weather forecasting.
5. In GPS (Global Positioning System).
6. Used to transport instruments and passengers to the space to perform experiments.

Question 7.
Here some working of objects are given. Put tick mark (✓) in the table which are applicable.
Answer:

AP Board 7th Class Science 5th Lesson 1 Mark Bits Questions and Answers Motion and Time

I. Multiple Choice Questions

1. The number of satellites launched in a single rocket and created a world record by ISRO.
A) 20
B) 104
C) 99
D) 100
Answer:
B) 104

2. SDSC – SHAR is located in
A) Chittoor
B) Nellore
C) Ananthapur
D) Guntur
Answer:
B) Nellore

3. The use of Rocket
A) to launch a space cratt
B) to launch a satellite
C) to shoot a missile
D) all
Answer:
D) all

4. The man made object around the earth is
A) Moon
B) Artificial satellite
C) Comet
D) Meteor
Answer:
B) Artificial satellite

5. An object is said to be in motion if……….
A) it changes its position with respect to its surroundings.
B) it does not changes its position with respect to its surroundings.
C) it changes the position of its particles with in the object.
D) till the above
Answer:
A) it changes its position with respect to its surroundings.

6. Force is required
A) to change the object from rest into motion
B) to change its direction
C) to change from motion to rest
D) all the above
Answer:
D) all the above

7. The total length of the path travelled by an object between two places is called….
A) Displacement
B) Speed
C) Distance
D) Track
Answer:
C) Distance

8. S.I units of distance is
A) Centimeter
B) Metre
C) Kilometre
D) Miles
Answer:
B) Metre

9. Hie shortest distance between two places along the straight-line path is called…
A) Displacement
B) Speed
C) Distance
D) Track
Answer:
A) Displacement

10. The basic unit of time is.
A) Minute
B) Second
C) Hour
D) All the above
Answer:
B) Second

11. Find the correct statement
i) 365 days is a year
ii) 100 year is a decade
A) both are correct
B) i only correct
C) ii only correct
D) both are wrong
Answer:
B) i only correct

12. These are used to measure shorter time intervals between two events accurately.
A) Wall clock
B) Sand clock
C) Stop clocks
D) Water clock
Answer:
C) Stop clocks

13. The time taken by the earth to complete one revolution around the sun.
A) Day
B) Month
C) Year
D) Hour
Answer:
C) Year

14. A mean solar day contains
A) 24 days
B) Year
C) 24 minutes
D) 24 hours
Answer:
D) 24 hours

15. If all points of a moving object move through the same distance in same direction, then the motion is said to be.
A) Translator motion
B) Rotatory motion
C) Oscillatory motion
D) All the above
Answer:
A) Translator motion

16. Find the odd one
A) coconut falling from a tree
B) movement of lift
C) motion of light rays
D) movement of body of snake
Answer:
D) movement of body of snake

17. If all the parts of a moving body follow a curved path with respect to a fixed centre or axis of rotation, it is said to be in …..
A) Translatory motion
B) Rotatory motion
C) Oscillatory motion
D) All the above
Answer:
B) Rotatory motion

18. Which of the following is not in rotatory motion?
A) Fan
B) Top
C) Cycle chain
D) Cycle wheel
Answer:
C) Cycle chain

19. Motion of cycle tyre
A) Translatory motion
B) Rotatory motion
C) Oscillatory motion
D) A & B
Answer:
C) Oscillatory motion

20. Sewing machine wheel :Rotatory motion :: Sewing machine needle : ?
A) Translatory motion
B) Rotatory motion
C) Oscillatory motion
D) All the above
Answer:
C) Oscillatory motion

21. The ’to and fro’ motion of an object about a fixed point that always following the samepath is called
A) Translatory motion
B) Rotatory motion
C) Circulatory motion
D) Oscillatory motion
Answer:
D) Oscillatory motion

22. In this motion, the direction of motion of the objects changes alternatively along the same path about a fixed point.
A) Translatory motion
B) Rotatory motion
C) Oscillatory motion
D) None of these
Answer:
C) Oscillatory motion

23. Uniform motion : Minute hand in a wall clock:: Non uniform motion: ?
A) Movement of butterfly
B) Revolution of Earth
C) A train going at a steady speed
D) The blades of a fan
Answer:
A) Movement of butterfly

24. What we need to know to decide whether{he motion is slow or fast?
A) distance covered
B) time taken
C) direction of motion
D) A & B
Answer:
A) distance covered

25. Odometer shows……
A) Speed of the vehicle
B) Distance travelled by the vehicle
C) Direction of the vehicle
D) A & B
Answer:
B) Distance travelled by the vehicle

26. The Speedometer shows
A) Speed of the vehicle
B) distance travelled by the vehicle
C) Direction of the vehicle
D) A & B
Answer:
A) Speed of the vehicle

27. The Speedometer shows the speed in……
A) m/s
B) km/s
C) m/h
D) km/h
Answer:
D) km/h

28. At a particular instant of time, we can find speed of a vehicle using
A) Odometer
B) Barometer
C) Speedometer
D) Both A & C
Answer:
C) Speedometer

29. 1 Km/h = ?
A) 5/60 m/s
B) 5/18 m/s
C) 60/5 m/s
D) 18/5 m/s
Answer:
B) 5/18 m/s

30. Satish Dhawan Space Centre (SDSC – SHAR) is located in this district
A) SPSR Nellore
B) Guntur
C) Chittoor
D) East godavari
Answer:
A) SPSR Nellore

II. Fill in the blanks

1. The ……………… by an object in a given interval of time can helps to decide whether it is faster or slower.
2. ……………… of an object can be defined as the distance travelled by it in a unit time.
3. Present chairman of iSRO ……………… .
4. ……………… are the devices that produce force or push to move an object forward into the space.
5. The movement of rocket is in a ……………… motion.
6. The movement of artificial satellites is in ……………… motion.
7. An object is said to be in ……………… if it changes its position with respect to its surroundings.
8. An object is said to be at ……………… if there is no change in its position with respect to its surroundings.
9. ……………… makes an object to move or tendio move.
10. The total length of the path travelled by an object between two places is called ……………… .
11. The basic unit of distance is ……………… .
12. S.I units of distance is ……………… .
13. The length of the straight-line path which is the shortest distance between two places is called ……………… .
14. The measurable period between two incidents is called ……………… .
15. The basic unit’of time is ……………… .
16. 1 minute = ……………… seconds
17. 10 years : 1 ………………
18. ……………… arA the most common time measuring devices.
19. ……………… are used to measure shorter time intervals between two events accurately.
20. The time between one new moon to the next is ……………… .
21. If all points of a moving object move through the same distance in same direction, then the motion is said to be ……………… .
22. If a body in translatory motion moves along a straight line then the motion is called ……………… .
23. If a body in translatory motion move along a curved path then the motion is called ……………… .
24. The motion of light rays is ……………… .
25. The movement of body of snake is in ……………… motion.
26. If all the parts of a moving body follow a curved path with respect to a fixed centre or axis of rotation, it is said to be in ……………… .
27. The imaginary line passing through the fixed centre is called ……………… .
28. ……………… is a special type of rotatory motidn, where the distance between the object and the axis of rotation remains fixed.
29. The to and fro’ motion of an object about a fixed point that always following the same path is called ……………… .
30. If a body covers equal distances in equal intervals of time, it is said to be in ……………… .
31. If a body covers unequal distances in equal intervals of time, it is said to be in ……………… .
32. The distance travelled by an object in a unit time is called ……………… .
33. ……………… shows the distance travelled by a vehicle.
34. At a particular instant of time, we can find speed of a vehicle using ……………… .
35. 1 Km / h = ……………… m/s
36. In a distance time graph, distance is usually plotted along ……………… axis, while time is usually plotted along
37. If the distance-time graph is a straight line, it indicates that the object is moving with ……………… .
38. From the distance-time graph we can find the ……………… of object.
39. Indian Space Research Organization, formed in ……………… .
40. ISRO maintains ……………… satellite for fast and reliable communication.
41. ISRO maintains remote sensing IRS satellites for ……………… .
42. On 18th June 2016 ISRO launched ……………… satellites in a single vehicle.
43. On 15th February 2017 ISRO launched ……………… satellites in a single rocket.
44. Satish Dhawan Space Centre (SDSC – SHAR) is located in ……………… .
Answer:

1. distance travelled
2. Speed
3. K. Sivan
4. Rockets
5. translatory
6. rotatory
7. motion
8. rest
9. Force
10. distance
11. centimeter
12. metre
13. displacement
14. time.
15. second
16. 60
17. decade
18. Clocks /watches
19. Stop clocks
20. month
21. translatory motion
22. rectilinear motion
23. curvilinear motion.
24. rectilinear motion
25. curvilinear
26. rotatory motion.
27. axis of rotation motion
28. Circular motion
29. oscillatory or vibratory
30. uniform motion
31. non-uniform motion
32. Speed
33. Odometer
34. speedometer
35. 5/18
36. Y-axis or the vertical, X-axis or the horizontal
37. a constant speed
38. speed
39. 1969
40. INSAT
41. earth observation
42. 20
43. 104
44. Sriharikota

III. Match the following

1.

Group – A	Group – B
A) Tree	1) Oscillatory motion
B) Butterfly	2) Curvilinear motion chine
C) Needle of a sewing ma	3) Rotatory motion
D) Light ray	4) Rectilinear motion
E) Wheel of a machine	5) Rest

Answer:

Group – A	Group – B
A) Tree	5) Rest
B) Butterfly	2) Curvilinear motion chine
C) Needle of a sewing ma	1) Oscillatory motion
D) Light ray	4) Rectilinear motion
E) Wheel of a machine	3) Rotatory motion

2.

Group – A	Group – B
A) Force	1) The total length of the path travelled
B) Distance	2) The distance travelled by an object in a  unit time.
C) Displacement	3) Cause of Motion
D) Time	4) Motion in a fixed path
E) Speed	5) The length of the straight-line path.
	6) The measurable period between two incidents.

Answer:

Group – A	Group – B
A) Force	3) Cause of Motion
B) Distance	1) The total length of the path travelled
C) Displacement	5) The length of the straight-line path.
D) Time	6) The measurable period between two incidents.
E) Speed	2) The distance travelled by an object in a  unit time.

3.

Group – A	Group – B
A) Curvilinear motion	1) Motion of strings of veena
B) Non-uniform motion	2) Motion of a snake
C) Oscillatory motion	3) Motion of light ray
D) Rotatory motion	4) Movement of minutes hand in a clock
E) Rectilinear motion	5) Directional motion
	6) Motion of butterfly in a graden

Answer:

Group – A	Group – B
A) Curvilinear motion	2) Motion of a snake
B) Non-uniform motion	6) Motion of butterfly in a graden
C) Oscillatory motion	1) Motion of strings of veena
D) Rotatory motion	4) Movement of minutes hand in a clock
E) Rectilinear motion	3) Motion of light ray

4.

Group – A	Group – B
A) Speedometer	1) Meters/Second
B) Odometer	2) Direction of the vehicle
C) Speed	3) Distance travelled
D) Time	4) Centimetres
E) Distance	5) Speed of a vehicle
	6) Seconds

Answer:

Group – A	Group – B
A) Speedometer	5) Speed of a vehicle
B) Odometer	3) Distance travelled
C) Speed	1) Meters/Second
D) Time	6) Seconds
E) Distance	4) Centimetres

Do You Know?

→ Like minutes and hours; week, fortnight, month, season, Ayana are also units for measuring time. Sun dial, sand clock, water clock etc., are used primitively to measure the time. Our ancestors noticed that many events in nature repeat themselves after definite Intervals of time. The time between one sunrise and the. next was called a day. Similarly, a month was measured from one new moon to the next. A year was fixed as the time taken by the earth to complete one revolution around the sun. A mean solar day contains 24 hours.

→ Circular motion is a special type of rotatory motion, where the distance between the object and the axis of rotation remains fixed.

These AP 7th Class Science Important Questions 4th Lesson Respiration and Circulation will help students prepare well for the exams.

AP Board 7th Class Science 4th Lesson Important Questions and Answers Respiration and Circulation

Question 1.
What is inspiration?
Answer:
The process of inhaling air is called inspiration.

Question 2.
What is expiration?
Answer:
The process of exhalation of air is called expiration.

Question 3.
What is respiratory rate?
Answer:
The number of times we inhale and exhale air in a minute is called the Respiratory Rate.,

Question 4.
What is the normal respiratory rate in human beings?
Answer:
The normal respiratory rate in human beings is 14 to 20 times per minute.

Question 5.
What are the only part of the human body which floats on water?
Answer:
Lungs are the only part of the human body which floats on water

Question 6.
What does our circulatory system consisting of?
Answer:
Circulatory system consists of Heart, Blood vessels and Blood

Question 7.
What is the pumping organ in the blood circulatory system.
Answer:
Heart is the pumping organ in the blood circulatory system.

Question 8.
How many chambers are there in the human heart? What are those?
Answer:
Human heart has four chambers, upper two chambers are called Atria and lower two chambers are called Ventricles.

Question 9.
What is heartbeat?
Answer:
The rhythmic contraction followed by its relaxation of heart is called heartbeat.

Question 10.
What is the instrument used to feel and measure the “heart beat?
Answer:
Stethoscope is the instrument used to feel and measure the heart beat.

Question 11.
What is the role of circulation in the human body?
Answer:
The process of circulation helps in the supply of digested food and oxygen to all parts of the body (cells) and also to bring back the waste material.

Question 12.
What is the fluid portion of the blood?
Answer:
Plasma is the fluid portion of the blood.

Question 13.
What are the different types of blood cells in the human blood?
Answer:
Blood cells are of three types – Red blood cells, White blood cells and Blood platelets.

Question 14.
Which blood cells act like police force of our body?
Answer:
White blood cells act like police force of our body.

Question 15.
Why red blood cells are red in colour?
Answer:
Red blood cells have a colouring pigment called Haemoglobin. It gives blood the red colour.

Question 16.
What is the function of haemoglobin?
Answer:
Haemoglobin acts as a carrier for oxygen and carbon dioxide and plays a key role in respiration. ,

Question 17.
What is the function of Blood platelets?
Answer:
Blood platelets play an important role in coagulation of blood when there are cuts and wounds.

Question 18.
Which organisms have colour less blood?
Answer:
Insects like cockroach have colour less blood.

Question 19.
Give examples for the organisms having blue coloured blood?
Answer:
Prawns, snails and crabs have blue coloured blood.

Question 20.
Expand NCDs.
Answer:
Non communicable diseases

Question 21.
Give some examples for non-communicable diseases.
Answer:
Heart attack, Cancer, Paralysis

Question 22.
What are the major causes for non-communicable diseases?
Answer:
Tobacco and alcohol use, poor eating habits, and lack of exercise are the major causes for non – communicable diseases.

Question 23.
What is immunity?
Answer:
Immunity is the inbuilt capacity of the body to fight and overcome the effects of disease causing germs.

Question 24.
What is meant by infection?
Answer:
The entry of disease-causing germs into our body to grow and multiply is called infection.

Question 25.
Expand SARS.
Answer:
Severe Acute Respiratory Syndrome

7th Class Science 4th Lesson Respiration and Circulation Short Questions and Answers

Question 1.
What is breathing? Explain brifly about breathing.
Answer:

1. The process of inhalation and exhalation of air is called Breathing.
2. During the process of inhalation the air with more oxygen and less carbon dioxide enters the lungs through nostrils.
3. During the process of exhalation the air with more carbondioxide and less oxygen is sent out from the lungs.

Question 2.
Write about lungs.
Answer:

1. Lungs are pink in colour spongy, elastic and sac like structures with many tiny air sacs.
2. They are placed safely in the ribcage formed by ribs in the chest cavity.
3. The right lung is slightly larger than the left one. ‘
4. The lungs do not possess muscles, so they cannot expand or contract on their own.

Question 3.
Why is the right lung larger than the left lung?
Answer:

1. Lungs are located in the chest cavity.
2. Heart is also present in the chest cavity on the left side.
3. So, there is less space for the left lung in the chest cavity.
4. As a result left lung is smaller with two lobes when compared with the right lung which had three lobes.

Question 4.
What is diaphragm? what is its role?
Answer:

1. A large thin muscular sheet called diaphragm is attached to the lower side of the ribcage and forms the floor of the chest cavity.
2. The process of breathing involves the movement of the diaphragm and the ribcage.
3. During inhalation diaphragm moves down as a result air enters the lungs.
4. During exhalation diaphragm moves back as a result air goes out of the lungs.
5. It play major role in the respiratory movements of men when compared with women.

Question 5.
Draw the flow chart air passage in respiration.
Answer:

Question 6.
What are plants respiratory organs?
Answer:

1. Plants being living organisms, have to breathe to survive. ,.
2. Plants take in oxygen and leave out carbon dioxide, as in any other living organisms.
3. The process of breathing takes place with the help of small openings in the leaves called stomata and in stem called lenticels.
4. The roots also need oxygen to produce energy, so they absorh the oxygen present in the air spaces between soil particles with the help of root hairs.

Question 7.
What is the need to plant more trees?
Answer:

1. Plants take in Oxygen and give out Carbon dioxide during respiration.
2. The same plants take in carbon dioxide and give out oxygen during the process of Photosynthesis.
3. So we should protect and plant more trees for a rich supply of oxygen.

Question 8.
What is the role of respiration?
Answer:

1. During the process of Respiration oxygen is absorbed and carbon dioxide is sent out of the body.
2. The process of respiration leads to the production of energy in all the living organisms.
3. Respiration takes place uninterrupted even when we are sleeping, eating, working or at rest.
4. Respiration takes place without our knowledge and effort and is very much essential for the survival of the organism.

Question 9.
How can we. prevent Covid-19?
Answer:
The best way to prevent and slow down spread is

1. Protecting ourselves by washing hands with soap or sanitizer
2. Not touching the face, eyes, nose, mouth
3. Wearing a facemask Maintaining social distance
4. Strictly adhering to covid protocol SMS – SANITISE, MASK, SOCIAL DISTANCE.

Question 10.
Write the differences between bacterial and viral disease.
Answer:

Bacterial diseases	Viral diseases
1. Can be cured using antibiotics.	1. Cannot be cured using antibiotics.
2. Only few need vaccines	2. Vaccine is the only remedy.
3. Ex : Typhoid, Cholera, Tuberculosis (TB).	3. Ex.: Common cold, Polio, HIV, CoViD-19

Question 11.
What is sneezing? When is it occur?
Answer:

1. The process of sudden uncontrolled expulsion of air through the nose by the lungs, due to irritation in the nasal passage is called Sneezing.
2. Sneezing occurs when we inhale air with dust, smoke, pollen or strong smells.

Question 12.
What is yawning? How is it caused?
Answer:

1. The uncontrolled action of opening of our mouth wide, to take a long, deep breath of air is called Yawning.
2. It is seen when a person is bored, stressed, feeling sleepy or very tired.
3. Yawning is caused when the respiratory rate gets slowed down resulting in insufficient supply of oxygen to the brain.
4. To overcome this situation, the body goes for the involuntary opening of the mouth to take in a long deep breath of air.

Question 13.
What is coughing? When does it happen?
Answer:

1. Coughing is the result of forceful contraction of the lungs to send out the unwanted substances through the mouth.
2. This happens when some strong smells or dust irritate the inner lining of the lungs.
3. By coughing the accumulated solid and semi -solid wastes in the lungs due to cold and other related respiratory disorders are also expelled out.

Question 14.
What is Deglutition apnea? What is its importance?
Answer:

1. The temporary arrest of respiration is called Apnea.
2. Deglutition or swallowing apnea occurs reflexly when the food is in the pharynx.
3. This process prevents the food from entering into the windpipe.
4. If food enters the windpipe it will have serious effects, so the larynx moves up to stop the food from entering the windpipe. Hence we should not talk while eating.

Question 15.
When do bleeding occurs? What is the first aid foe it?
Answer:

1. Bleeding takes place when we are injured or there is a cut,
2. First the bleeding injury is to be washed with clean water.
3. Use cotton or a cloth to clean the injured are ‘
4. Then use cotton or a bandage cloth to cover the injury to stop the flow of blood.
5. Take the injured person to the nearest Doctor or Hospital if bleeding does not stop.

7th Class Science 4th Lesson Respiration and Circulation Long Questions and Answers

Question 1.
Which of the following statements are wrong? Give reasons.
1) There is no har m in trying a cigarette once, because one can stop after that.
2) One cigarette a day does not harm any more.
3) Will power alone can help a smoker to stop smoking.
4) Smoking helps you feet good and relaxed.
5) Smoking is not harmful to health.
Answer:

1. Wrong. Because almost all smoker starts by trying just once but it will become a habit hard to leave.
2. Wrong. Because every cigarette you smoke is doing damage to your body, which ultimately causes heartattack, stroke and lung diseases.
3. Wrong. Because along with will power, the love and support of the family and friends combined with medical arid psychological treatment also needed to quit smoking.
4. Wrong. Because smoking may make you feel relaxed temporarily but the long term harmful effects will affect your health, wealth and life style.
5. Wrong. Because smoking leads to several health problems such as Lung Cancer, Tuberculosis and other respiratory disorders. So, never try to start smoking.

Question 2.
Describe the structure of human heart.
Answer:

1. Heart is the pumping organ in the blood circulatory system.
2. It’s about the size of one’s fist.?
3. It is located in the centre of the chest cavity slightly bent towards the left.
4. It has four chambers, upper two chambers are called Atria and lower two chambers are called Ventricles.
5. The walls of the chambers are made of muscles which contract and relax, regularly and rhythmically to pump the blood.

Question 3.
How do you prove the aerobic respiration?
Answer:
Aim: To prove the aerobic respiration.

Apparitors : Wide-mouthed bottle, lid, sprouting seeds, beaker, lime water.

Procedure:

1. Take a wide mouthed bottle and place a handful of sprouting seeds in it.
2. Prepare some fresh lime water in a small container and place it carefully in one corner of the bottle.
3. Close the cap of the bottle and apply vaseline on the edges to make it air-tight.
4. Leave the apparatus undisturbed for a day or two days.
5. After two days open the cap and carefully take out the lime water container and observe the changes.

Observation:
The lime water turns into milky white.

Conclusion:
Lime water turned milky white by carbon dioxide, which is released by germinated seeds through aerobic respiration

Prove:
It is proven that carbon dioxide is released in aerobic respiration

Question 4.
What are blood vessels? Write about different types of blood vessels in human body.
Answer:

1. The tube like structures through which blood flow in the human body are called blood vessels.
2. There are three types of blood vessels in the human body. 1. Arteries, 2. Veins and 3. Blood capillaries –
3. Arteries carry blood with more oxygen from heart to body parts.
4. Veins carry blood with more carbon dioxide from the body parts to the heart.
5. Blood capillaries which are very thin narrow blood vessels that connect the arteries with the veins and distribute the blood to the body parts.

Question 5.
Write about composition and functions of blood.
Answer:

1. Human blood is composed of Blood cells and plasm. Plasma is the fluid portion of the blood.
2. Blood cells are of three types – Red blood cells, White blood cells and Blood platelets.
3. White blood cells are again of different types.
4. The white blood cells boost our immunity and protect us from the harmful, disease causing micro organisms that enter into our body.
5. They act like police force of our body.
6. Red blood cells have a colouring pigment called Haemoglobin in the RBC, which gives blood the red colour.
7. Haemoglobin acts as a carrier for oxygen and carbon dioxide and plays a key role in respiration.
8. Blood platelets play an important role in coagulation of blood when there are cuts and wounds.
9. Blood plays an important role in the transport of materials in animals.
10. Blood is the medium to carry the digested food materials and the inhaled oxygen to all parts of the body.

Question 6.
What preventive measures will you suggest to be healthy, strong and disease free in the context of covid 19.
Answer:

1. Protecting ourselves by washing hands with soap or sanitizer,
2. Not touching the face, eyes, nose, mouth
3. Wearing a face mask
4. Maintaining social distance
5. Strictly adhering to covid protocol SMS – SANITISE, MASK, SOCIAL DISTANCE.
6. Taking steam inhalation twice a day.
7. Drinking hot milk mixed with turmeric,
8. Taking meals when hot,
9. Taking a nutritive balanced diet,
10. Practicing breathing exercises and yoga,
11. Gargling with warm water and Taking vitamin C

Question 7.
What is Choking? What is the first aid for it?
Answer:

1. Choking occurs when the wind pipe is obstructed by an object leading to blocking of air.
2. Choking has to be attended immediately as it is dangerous.
3. In adults, hold the person from behind around the abdomen just below the ribs.
4. Press quickly and repeatedly until the person gets relief by coughing or vomiting.
5. In case of children who usually put seeds, coins or bottle caption their mouth and get choked.
6. The child should be made to lie down upside down in the lap of an adult.
7. Then, the part of the back between the shoulder bones has to be tapped strongly until the object comes out.
8. Take him to the doctor immediately.

AP Board 7th Class Science 4th Lesson 1 Mark Bits Questions and Answers Respiration and Circulation

I. Multiple Choice Questions

1. In which process accumulated semisolid wastes come out?
A) Sneezing
B) Yawning
C) Coughing
D) Apnea
Answer:
C) Coughing

2. Which of the following is occured when food enters in the wind pipe?
A) Sneezing
B) Yawning
C) Coughing
D) Apnea
Answer:
D) Apnea

3. First aid for bleeding is
A) Create pressure on the diaphragm
B) Cover with bandage
C) Upside down
D) Above all
Answer:
B) Cover with bandage

4. Which of the following requires oxygen?
A) Aerobic respiration
B) Anaerobic respiration
C) Both A & B
D) None
Answer:
A) Aerobic respiration

5. The process of inhaling air is called
A) Breathing
B) Inspiration
C) Expiration
D) Respiration
Answer:
B) Inspiration

6. The opening of the nose is called
A) Nostrils
B) Nasal cavity
C) Pharynx
D) wind pipe
Answer:
A) Nostrils

7. Inspiration occurs due to
A) Ribcage move upward
B) Diaphragm move upward
C) Air enters the lungs
D) A & B
Answer:
A) Ribcage move upward

8. Quantity of nitrogen present in the inhaled air …………%.
A) 21
B) 25
C) 78
D) 0.4
Answer:
C) 78

9. Quantity of water vapour in exhaled air 0.4 …………%.
A) 15
B) 4
C) 78
D) 3
Answer:
D) 3

10. This gas turns lime water into milky white
A) Oxygen
B) Hydrogen
C) Carbon dioxide
D) Nitrogen
Answer:
C) Carbon dioxide

11. Find the correct statement
i) In the lungs, Carbon dioxide from the inhaled air is absorbed by the blood vessels present in the lungs.
ii) Oxygen collected by the blood vessels from all parts of the body enters into the Lungs.
A) both are correct
B) i only correct
C) ii only correct
D) both are wrong
Answer:
D) both are wrong

12. This will help to quit smoking.
A) Will power
B) support of the family and friends
C) medical and psychological treatment
D) All the above
Answer:
D) All the above

13. Nicotine is present in this leaf
A) Neem
B) Pipal
C) Tobacco
D) Betel
Answer:
C) Tobacco

14. Find the odd one
A) Grasshopper
B) Cockroach
C) Earthworm
D) Honey bee
Answer:
C) Earthworm

15. Frogs respires through
A) Lungs
B) Skin
C) Tracheae
D) Both A & B
Answer:
D) Both A & B

16. Fish respire through
A) Gills
B) Skin
C) Lung
D) Both A & B
Answer:
A) Gills

17. Marine animal that respire through lung is
A) Fish
B) Dolphins
C) Prawn
D) Star fish
Answer:
B) Dolphins

18. Respiration in plants occurs through
A) Stomata
B) Lenticles
C) Root hairs
D) All the above
Answer:
D) All the above

19. Honey bee : Tracheae :: Earth worm : ?
A) Gill
B) Lung
C) Skin
D) None of, these
Answer:
C) Skin

20. In this process, energy released in our body
A) Photosynthesis
B) Digestion
C) Respiration
D) Circulation
Answer:
C) Respiration

21. This process helps in the supply of digested food and oxygen to all parts of the body
A) Digestion
B) Circulation
C) Excretion
D) Photosynthesis
Answer:
B) Circulation

22. This is not a part of circulatory system ….
A) Lungs
B) Heart
C) Blood vessels
D) Blood
Answer:
A) Lungs

23. Upper two chambers of the heart are called
A) Arteries
B) Ventricles
C) Atria
D) Veins
Answer:
C) Atria

24. The fluid portion of the blood is
A) RBC
B) WBC
C) Blood platelets
D) Plasma
Answer:
D) Plasma

25. They protect us from the harmful, disease causing micro organisms that enter into our body.
A) RBC
B) WBC
C) Blood platelets
D) Plasma
Answer:
B) WBC

26. They play an important role in coagulation of blood…….
A) RBC
B) WBC
C) Blood platelets
D) Plasma
Answer:
C) Blood platelets

27. They plays a key role in respiration.
A) RBC
B) WBC
C) Blood platelets
D) Plasma
Answer:
A) RBC

28. Which of the following does not have blue coloured blood
A) Prawns
B) Snails
C) Cockroach
D) Crabs
Answer:
D) Crabs

29. This life processes play an important role in release of energy in organisms.
A) Digestion
B) Respiration
C) Circulation
D) All the above
Answer:
A) Digestion

30. Which of the following is not a non communicable diseases?
A) Heart attack
B) COVID – 19
C) Cancer
D) Paralysis
Answer:
B) COVID – 19

31. Identify the bacterial disease
A) Common cold
B) Polio
C) Tuberculosis
D) HIV
Answer:
C) Tuberculosis

32. Identify the viral, disease
A) Typhoid
B) Common cold
C) Cholera
D) Tuberculosis
Answer:
B) Common cold

33. SMS protocol is for this disease
A) Polio
B) COVID
C) Cancer
D) Paralysis
Answer:
B) COVID

34. This is caused due to insufficient supply of Oxygen to the brain.
A) Coughing
B) Sneezing
C) Deglutition
D) Yawning
Answer:
D) Yawning

35. This process prevents the food from entering into the windpipe.
A) Coughing
B) Sneezing
C) Deglutition
D) Yawning
Answer:
C) Deglutition

36. This occurs when the wind pipe is obstructed by an object leading to blocking of air….
A) Coughing
B) Sneezing
C) Deglutition
D) Choking
Answer:
D) Choking

II. Fill in the blanks

1. COVID -19 is caused by a virus called …………………… .
2. SARS means …………………… .
3. Giving assistance before a doctor attending is called …………………… .
4. The temporary arrest of respiration is called …………………… .
5. The process of inhalation and exhalation of air is called …………………… .
6. The process of inhaling air is called …………………… .
7. The process of exhalation of air is called …………………… .
8; The number of times we inhale and exhale air in a minute is called the
9. We breathe about …………………… times per minute normally.
10. One inhalation and one exhalation together called one
11. …………………… is the first part of the Wind pipe.
12. …………………… is the process which helps in the release of energy in our body.
13. …………………… are the respiratory organs in human beings.
14. The …………………… lung is slightly larger than the …………………… one.
15. Wind pipe is kept in its shape by …………………… .
16. Lungs are protected by …………………… .
17. …………………… is the thin muscular sheet attached to the lower side of the ribcage.
18. …………………… forms the floor of the chest cavity.
19. …………………… play key role in the respiratory movements in man.
20. …………………… play key role in the respiratory movements in woman.
21. …………………… are the only part of the human body which floats on water
22. …………………… is the gas produced in photosynthesis.
23. Percentage of carbon dioxide in the inhaled air is …………………… .
24. Percentage of oxygen in the inhaled air is …………………… .
25. Percentage of carbon dioxide in the exhaled air is …………………… .
26. Percentage of oxygen in the exhaled air is …………………… .
27. Lime water turns milky white when it reacts with …………………… .
28. Glucose + Oxygen → …………………… + water + Energy
29. Tobacco smoke contains a highly dangerous substance called
30. …………………… respiration is present in insects.
31. Breathing through the skin is called …………………… respiration.
32. Respiration carried out by gills is called …………………… .
33. Respiration through is called Pulmonary respiration.
34. Plants respire through on the leaf and on the stem.
35. …………………… is the pumping organ in the blood circulatory system.
36. Upper two chambers of the heart are called and lower two chambers are called …………………… .
37. The rhythmic contraction followed by its relaxation of the heart is called …………………… .
38. Heart beat can be felt and measured by an instrument called …………………… .
39. …………………… carry blood with more oxygen from heart to body parts.
40. …………………… carry blood with more carbon dioxide from the body parts to the heart.
41. …………………… connect the arteries with the Veins
42. …………………… is the fluid portion of the blood.
43. …………………… act like police force of our body.
44. Red blood cells have a colouring pigment called …………………… .
45. …………………… acts as a carrier for oxygen and carbon dioxide in blood.
46. …………………… play an important role in coagulation of blood …………………… .
47. Blood present in cockroach is
48. …………………… is the storage point for undigested food.
49. Blood in snails is …………………… in colour.
50. …………………… was the new disease that created a global impact recently.
51. …………………… is the inbuilt capacity of the body to fight and overcome the effects of disease-causing germs.
52. The entry of disease-causing germs into our body is called ……………… .
53. COVID-19 virus spreads primarily through …………………… of infected person.
Answer:

1. SARS CoV – 2
2. Severe Acute Respiratory Syndrome
3. First aid.
4. Apnea
5. breathing
6. inspiration
7. expiration
8. Respiratory Rate
9. 14 to 20
10. breath
11. Larynx
12. Respiration
13. Lungs
14. right
15. C Shaped rings
16. ribcage
17. Diaphragm
18. Diaphragm
19. Diaphragm
20. Ribcage
21. Lungs
22. Oxygen
23. 0.04%
24. 21%
25. 4%
26. 15%
27. carbon dioxide
28. Carbon dioxide
29. Nicotine
30. Tracheal
31. cutaneous
32. branchial respiration
33. lungs
34. stomata, lenticels
35. Heart
36. atria, ventricles
37. heartbeat
38. Stethoscope
39. Arteries
40. Veins
41. Blood capillaries
42. Plasma
43. White blood cells
44. Haemoglobin
45. Haemoglobin
46. Blood platelets
47. colourless
48. Rectum
49. bluish
50. COVID-19
51. Immunity
52. infection
53. droplets of saliva or nasal discharges

III. Match the following

1.

Group – A	Group – B
A) Opening of the nose	1) Nostrils
B) Mucus and nasal hair	2) Nasal cavity
C) Common chamber	3) Lungs
D) Wide tube	4) Wind pipe
E) Branches of wind pipe	5) Bronchi
F) Spongy and elastic	6) Pharynx

Answer:

Group – A	Group – B
A) Opening of the nose	1) Nostrils
B) Mucus and nasal hair	2) Nasal cavity
C) Common chamber	6) Pharynx
D) Wide tube	5) Bronchi
E) Branches of wind pipe	4) Wind pipe
F) Spongy and elastic	3) Lungs

2.

Group – A	Group – B
A) Red blood cells	1) Earthworm
B) White blood cells	2) Cockroach
C) Blood platelets	3) Carrier for oxygen and carbondioxide
D) Colourless blood	4) Coagulation of blood
E) Blue colour blood	5) Police force of our body
	6) Snails

Answer:

Group – A	Group – B
A) Red blood cells	3) Carrier for oxygen and carbondioxide
B) White blood cells	5) Police force of our body
C) Blood platelets	4) Coagulation of blood
D) Colourless blood	2) Cockroach
E) Blue colour blood	6) Snails

3.

Group – A	Group – B
A) Sneezing	1) Wastes in the lungs expelled out
B) Yawning	2) Inhale air with dust
C) Coughing	3) Obstruction Of wind pipe leading to blocking Of air
D) Apnea	4) Bleeding injury
E) Choking	5) Insufficient supply of Oxygen to the brain
	6) Prevents the food from, entering into the windpipe

Answer:

Group – A	Group – B
A) Sneezing	2) Inhale air with dust
B) Yawning	5) Insufficient supply of Oxygen to the brain
C) Coughing	1) Wastes in the lungs expelled out
D) Apnea	6) Prevents the food from, entering into the windpipe
E) Choking	3) Obstruction Of wind pipe leading to blocking Of air

4.

Group – A	Group – B
A) Typhoid	1) Non communicable diseases
B) Polio	2) Pumping organ in the circulatory system
C) Heart attack	3) Bacterial disease
D) Capillaries	4) Carry blood with more oxygen
E) Heart	5) Viral disease

Answer:

Group – A	Group – B
A) Typhoid	3) Bacterial disease
B) Polio	5) Viral disease
C) Heart attack	1) Non communicable diseases
D) Capillaries	6) Connect the arteries with the veins
E) Heart	2) Pumping organ in the circulatory system

Do You Know?

→ Lungs are the only part of the human body which floats on water.

→ The efforts of scientists like Von Helmont and Joseph Black led to the discovery of carbon dioxide. Joseph Priestley and Lavoiser discovered Oxygen.

→ Whales, Dolphins, Seals etc. are marine animals which live in water but have lungs. So, they come up regularly ones the surface to breathe the air.

→ Plants take in Oxygen and give out Carbon dioxide during respiration. The same plants take in carbon dioxide and give out oxygen during the process of Photosynthesis. So we should protect and plant more trees for a rich supply of oxygen.

These AP 7th Class Science Important Questions 3rd Lesson Nutrition in Organisms will help students prepare well for the exams.

AP Board 7th Class Science 3rd Lesson Important Questions and Answers Nutrition in Organisms

Question 1.
Plants are also organisms. What is the food for them?
Answers:
Plants also need food like carbohydrates. But they prepare their own food.

Question 2.
How do plants get their food?
Answer:
Plants take carbon dioxide from air, water from soil, light energy from sun light and prepare their own food by using chlorophyll present in its green parts.

Question 3.
What is nutrition?
Answer:
The process of intake and utilization of food by organisms is called nutrition.

Question 4.
What are the different types of nutritions?
Answer:
Nutrition is of two types. 1) Autotrophic nutrition and 2) Heterotrophic nutrition

Question 5.
What is autotrophic nutrition?
Answer:
The mode of nutrition in which organisms make food by themselves is called autotrophic nutrition.

Question 6.
What is heterotrophic nutrition?
Answer:
The mode of nutrition in which organisms depend on other organisms for food is called heterotrophic nutrition.

Question 7.
Do all plants Autotrophs?
Answer:
No, there are some heterotrophic plants like cuscuta.

Question 8.
What kind of nutrition is seen in mush rooms?
Answer:
Saprophytic nutrition is seen in mushrooms.

Question 9.
What kind of nutrition is seen in animals?
Answer:
Heterotrophic nutrition is seen; in animals.

Question 10.
What is chlorophyll? Where is it present?
Answer:
Green coloured pigment present in plants is called Chlorophyll. It is present in the chloroplast of the plant cell.

Question 11.
What are the raw materials required for the preparation of food by green plants?
Answer:
Carbon dioxide, water, sunlight and chlorophyll.

Question 12.
Which gas is taken by plants during photosynthesis?
Answer:
Plants take carbon dioxide during photosynthesis.

Question 13.
Name the food material formed in plants.
Answer:
Glucose/ Carbohydrate is the food material formed in plants.

Question 14.
Where do photosynthesis happens in plants?
Answer:
Photosynthesis happens in the chloroplast of the green plants.

Question 15.
What is the role of chlorophyll in photosynthesis?
Answer:
Chlorophyll captures the energy of the sunlight. This energy is used to synthesise • food from carbon dioxide and water dhfihg photosynthesis.

Question 16.
Do the plants with red and brown coloured leaves perform Photosynthesis?
Answer:
Red and brown coloured leaves also have chlorophyll. The iiarge artidunt of ired, brown and other pigments mask the green colour So photosynthesis takes place in these leaves also.

Question 17.
What is chlorophyll?
Answer:
The green parts of plant contain a colouring pigment called chlorophyll.

Question 18.
What are Stomata?
Answer:
Stomata are the small openings present on the lower surface of the leaf through which gaseous exchange takes place.

Question 19.
What is the food formed in the plants?
Answer:
Plants form sugars first during the photosynthesis. Later it is converted into starch and stored in the plant body.

Question 20.
What are micro nutrients?
Answer:
Nutrient elements required in minute quantities to the plants are called micro nutrients.

Question 21.
What is saprophytic nutrition?
Answer:
The mode of nutrition in which organisms take in nutrients in the form of solution from dead and decaying matter is called saprophytic nutrition.

Question 22.
Give examples for saprophytes.
Answer:
Certain microorganisms such as bacteria and fungi like mushrooms, bread mould are ‘ the examples for saprophytes.

Question 23.
How do saprophytes help us?
Answer:
Saprotrophs grow on the dead bodies, decompose them ancl mix them With the soil. Thus thay help us by cleaning the earth surface by removing the dead and decaying matter.

Question 24.
Give one example for parasitic plant.
Answer:
Cuscuta/Dodder plant

Question 25.
Give one example for parasitic animal.
Answer:
Intestinal worms

Question 26.
Give one example for symbiotic nutrition.
Answer:
lichens.

Question 27.
What is a host in parasitism?
Answer:
Organism that provide food and shelter to the parasite is called host.

Question 28.
What is parasite?
Answer:
Parasite is an organism which grow on /in the body of another organism (host) and get food from it.

Question 29.
When do we observe National Deworming Day? What is its aim?
Answer:
Every year February 10 and August 10 are observed as the National Deworming Day (NDD). The day aims at eradicating intestinal worms among children in the age group of 1-19 years. On this day, Albendazole tablet (deworming drug) is administered to children.

Question 30.
DO we have any structures like vacuole in our body? Where do the food eaten by us go?
Answer:
We don’t have vacuole’ like structures in our body instead we have a long tubular digestive tract/ alimentary canal. The food eaten by us go in to this digestive system to get digest and absorb into the body.

Question 31.
How many chambers are there in the stomach of ruminants? What are those?
Answer:
Ruminants have four chambers in stomach. They are rumen, reticulum, omasum and abomasum.

Question 32.
What is cud?
Answer:
Partially digested food in the rumen of grass eating animals is called cud.

Question 33.
What is rumination?
Answer:
The process of bringing back the cud in to the mouth in small lumps chews it again is called rumination.

Question 34.
What are ruminants?
Answer:
Grass eating animals that performs the rumination are called ruminants.

Question 35.
How do cellulose get digest in the ruminants?
Answer:
In ruminants,, the cellulose of the food is digested by the action of certain bacteria present in the rumen of grass eating animals.

Question 36.
What is enamel?
Answer:
Enamel is the outermost layer of teeth. It is the hardest material in the human body.

Question 37.
What is tooth decay?
Answer:
Damage of enamel on the tooth due to action of acids in the mouth is called tooth decay.

Question 38.
What are the major culprits of tooth decay?
Answer:
Chocolates, sweets, soft drinks and other sugar products are the major culprits of tooth decay.

Question 39.
Where do the process of digestion starts in our body?
Answer:
The process of digestion starts in the buccal cavity in our body.

Question 40.
Where do the process of digestion completes in our body?
Answer:
The process of digestion completes in small intestine.

Question 41.
What absorbs the digested food from our digestive track?
Answer:
Finger-like out growths called villi present in the small intestine absorbs the digested food from our digestive track.

Question 42.
Through which part undigested food is sent out of our body?
Answer:
Undigested food is sent out of our body through the anus.

Question 43.
What are the common problems associated with the digestive track?
Answer:
The most common problems associated with the digestive tract are diarrhoea, constipation, irritable bowel syndrome, acidity, etc.

Question 44.
What do you understand from the given picture?

Answer:
From the given picture, I understand that skipping meals, stress, strain, cool drinks, junk food, consumption of alcohol and tobacco products are not good for our health especially to our digestive system.

7th Class Science 3rd Lesson Nutrition in Organisms Short Questions and Answers

Question 1.
Why are leaves green in colour?
Answer:

1. Leaves are green as they have chloroplasts.
2. Chloroplasts are the special structures present only in plant cells and absent in animal cells.
3. These chloroplasts consisting of a green coloured pigment called chlorophyll in them.
4. This chlorophyll is responsible for all this greenery and play key role in preparation of food.

Question 2.
How can you confirm the occurrence of photosynthesis in a plant?
Answer:

1. Glucose formed in photosynthesis is converted and stored in the form of starch.
2. So, the presence of starch in leaves indicates the occurrence of photosynthesis.
3. It can be confirmed by testing the leaf extract with Iodine solution.

Question 3.
Why leaves are called “food factories of plants”.?
Answer:

1. Plants get carbon dioxide from air, water from soil, and energy from sunlight for synthesis of their food.
2. The synthesis of food occurs in all green parts of plant body.
3. These green parts contain a colouring pigment called Chlorophyll.
4. It is more in leaves so leaves are called as “food factories of plants”.

Question 4.
Prepare a table comparing the method of our food preparation with that of plants.
Answer:

	Preparation of Boiled Rice	Preparation of food by green plants
Raw material	Rice, Water	Carbon dioxide, water
Source of energy	Firci from stove	Sunlight
Happens in	Vessel/ cooker	Chloroplast in green parts
Finally forms	Boiled rice	Glucose/Carbohydrates

Question 5.
How do the raw materials; required for photosynthesis reach the leaf?
Answer:

1. Carbon dioxide required for photosynthesis enters into the leaf through the stomata.
2. Water absorbed by the roots transported to the leaf through the stem.
3. Leaf get sunlight when it exposed to the sun.
4. Chlorophyll is present with the leaf.

Question 6.
What is the importance off sunlight in photosynthesis?
Answer:

1. Sun light is the source of energy in the process of photosynthesis.
2. The solar energy is captured by the leaves and stored in the plant in the form of food.
3. Thus, sun is the ultimate source of energy for all living organisms.

Question 7.
Write a short note on insectivorous plants.
Answer:

1. There are some plants that eat insects.
2. Being green in colour, they can manufacture their own food.
3. But as they grow in areas deficient in nitrogen, they meet their nitrogen requirements from insects.
4. Leaves of these plants are specially modified to trap insects.
5. Nepenthes, droseras, Utricularia (bladderwort), Venus fly trap (Dionaea) are examples of some such insectivorous plants.
6. These are also called as carnivorous plants.

Question 8.
Write a short note on saprophytic nutrition.
Answer:

1. Some organisms grow on dead and decaying matter.
2. They secrete digestive juices on it convert it into a solution and then absorb the nutrients from it.
3. This mode of nutrition in which organisms take in nutrients in the form of solution from dead and decaying; matter is called saprophytic nutrition.
4. Generally we see this saprophytic nutrition in certain microorganisms such as bacteria and fungi like mushrooms, bread mould etc.

Question 9.
Write a short note on symbiosis.
Answer:

1. Some plants of the Dal family (legume plants) posses a type of bacteria growing on their roots in nodules.
2. The bacteria fixes nitrogen for the plant while it gets shelter in the roots of these plants.
3. Such an association is beneficial to both groups and called symbiosis.
4. In organisms called lichens, a chlorophyll-containing partner, which is an algae, and a fungus live together.
5. The fungus provides shelter, water and minerals to the alga and in return, the alga „ provides.

Question 10.
What is parasitism? Give examples.
Answer:

1. Type of association between two organisms for food in which one organism get benefited and other is vitiated is called parasitism (Parasitic nutrition).
2. The organism which is getting benefit is called parasite.
3. Example for parasitic plant is Cuscuta.
4. Example for parasitic animal is intestinal worm.

Question 11.
How does dodder plant get its food?
Answer:

1. Plants like Cuscuta/ Dodder plant (Bangaru teega) take readymade food from the plant on which it is climbing. ,
2. They develop special roots called haustoria, which penetrate into the tissues of the host plant and absorb food materials from them.
3. This causes harm to the host plant gradually.
4. This kind of nutrition is called parasitism.

Question 12.
How do animals take their food? Where do they digest it?
Answer:

1. Animals obtain their food from other organisms.
2. They take their food in the form of solid or liquid.
3. They take the food into the body for digestion.
4. Digestion occurs inside the body.

Question 13.
What are the parts of human digestive system?
Answer:

1. The digestive system consists of the alimentary canal and digestive glands.
2. The total length of alimentary canal is about 9 meters.
3. Its main parts are mouth, oral cavity/ buccal cavity, oesophagus, stomach, small intestine, large intestine, rectum and anus.
4. The salivary glands, liver and pancreas are the digestive parts connected to the alimentary canal.

Question 14.
Write a short note on tooth decay?
Answer:

1. Normally Bacteria present in our mouth are not harmful to us.
2. If we do not clean our teeth and mouth after eating, many harmful bacteria begin to live and grow in it.
3. These bacteria breakdown the sugars present from leftover food and release acids.
4. These acids gradually damage teeth. This is called tooth decay.
5. If it is not treated in time, it causes severe toothache and in extreme cases results in tooth loss.
6. Chocolates, sweets, soft drinks and other sugar products are major causes of tooth decay.

Question 15.
How do bad habits effect our digestive system?
Answer:

1. Bad habits like smoking, chewing of tobacco, drinking of alcohol effect our health adversely. .
2. Drinking of alcohol can lead to liver diseases, digestive problems.
3. It causes cancer of the mouth, throat, oesophagus arid liver.
4. Consuming tobacco products, tobacco particles stick to teeth, gums, and skin of the mouth cavity which leads to swelling, injury, pain and also causes throat and intestine cancer.

Question 16.
How do vajrasana help our body?
Answer:

1. Vajrasana increases flow of blood into our stomach area, thus improving our bowel movements and relieving constipation.
2. It also keeps us to get rid of gas and acidity.

Question 17.
Draw the diagram of stomata and label the parts.
Answer:

Question 18.
Draw the diagram showing nutrition in amoeba.
Answer:

Question 19.
Which habit should be practised for the health of teeth? Why?
Answer:
We should clean our teeth daily at least for twice. Once in the morning after we wakeup. This helps to remove the bacteria accumulated over night in our mouth. And second time before going to bed. This helps to remove any food particles remain in mouth. Otherwise these food particles increase the growth of bacteria and releasing of acids. So for the health of our teeth, we should brush our teeth at least for twice.

7th Class Science 3rd Lesson Nutrition in Organisms Long Questions and Answers

Question 1.
What is nutrition? Describe different types of nutritions.
Answer:
The process of intake and utilization of food by organisms is called nutrition. This is mainly of two types.

1. Autotrophic nutrition
2. Heterotrophic nutrition

1) Autotrophic nutrition :
The mode of nutrition in which organisms make food by themselves is called autotrophic nutrition. Ex: Green plants

2) Heterotrophic nutrition :
The mode of nutrition in which organisms depend on other organisms for food is called Heterotrophic nutrition. This is again of three types
i) Saprophytic nutrition:
The mode of nutrition in which organisms take in nutrients in the form of solution from dead and decaying matter is called saprophyticnutrition.
Ex: Certain microorganisms such as bacteria and fungi like mushrooms, bread mould etc.

ii) Parasitic Nutrition :
This type of association between two organisms for food in which one organism get benefited and other is vitiated is called parasitic nutrition.
Ex: Cuscuta, Intestinal worms

iii) Holozoic Nutrition :
Holozoic Nutrition is the mode of heterotrophic nutrition in which the food is taken in solid or liquid form from the outside and is digested inside the body.
Ex: Amoeba. Human beings

Question 2.
What is holozoic nutrition? What are the steps involved in it?
Answer:
Holozoic Nutrition is the mode of heterotrophic nutrition in which the food is taken in solid or liquid form from the outside and is digested inside the body.

The steps involved in holozoic nutrition are

1. Ingestion – Food is taken into the body.
2. Digestion – Conversion of food into simple soluble forms.
3. Absorption – Transfer of food to the blood.
4. Assimilation – Absorbed food became the part of the body. .
5. Egestion – Removal of waste products and undigested food from the body.

Question 3.
Describe the nutrition in amoeba.
Answer:

1. Amoeba is a microscopic single-celled organism found in pond water.
2. Amoeba has a cell membrane, a rounded, dense nucleus and many small bubble¬like vacuoles in its cytoplasm.
3. Amoeba constantly changes its shape and position.
4. It pushes out one. or more finger-like projections, called pseudopodia or false feet ‘ for movement and capture of food.
5. Food vacuole forms around the captured food.
6. Food get digested in it, absorbed into the cytoplasm and assimilates.
7. Finally undigested food is sent out by opening this vacuole out at the body surface.

Question 4.
Is the nutrition in human beings holozoic? Justify your answer.
Answer:

1. Yes, nutrition in human beings is holozoic nutrition.
2. We take food in the form of solids or liquids.
3. It get’s digested in the digestive system.
4. Digested food is absorbed by the blood.
5. Blood transports digested food to different parts of the body for assimilation.
6. Undigested food will be ejected out of the body.
7. So the nutrition in human beings is holozoic nutrition.

Question 5.
Explain the process of digestion in grass eating animals.
Answer:

1. Grass eating animals have four chambers in stomach.
2. They are rumen, reticulum, omasum and abomasum.
3. They quickly swallow the grass and store it in a part of the stomach called rumen.
4. In rumen, food gets partially digested and is called cud.
5. But later the cud returns to the mouth in small lumps and animal chews it again.
6. This process is called rumination and these animals are called ruminants.
7. The grass is rich in cellulose, a type of carbohydrate.
8. In ruminants, the cellulose of the food is digested by the action of certain bacteria present in the rumen of grass eating animals.

Question 6.
Make a table showing types of teeth, their number and function in human beings.
Answer:

Type of teeth	Number of teeth	Function
1. Incisors	8	cut food
2. Canines	4	tear food
3. Premolars	8	crush food
4. Molars	12	grind food

Question 7.
Describe the functions of various parts of human digestive system.
Answer:
Different parts of human digestive system performs different functions as mentioned below.

1. Mouth Food is taken into the body through it. It leads into Buccal Cavity.
2. Buccal cavity contains tongue, teeth and secretions of Salivary glands. Carbohydrate digestion starts here.
3. Pharynx is the common chamber for both digestive track and respiratory track. It leads into Oesophagus.
4. Oesophagus is a muscular tubular structure that connects pharynx with Stomach.
5. Stomach is a muscular sac like structure. Food is grinded well and mix with its juices. Proteins digestions tarts in the stomach. Hydrochloric acid in the stomach kills Bacteria in the food.
6. Duodenum is the first part of the small intestine. Bile juice from liver, Pancreatic juice from pancreas enters into it and helps in digestion.
7. Small intestine is about six metre long. Digestion of food is completed here with the help of its juices. Its inner wall have thousands of finger-like outgrowths called villi. They absorb the digested food. Blood transport it to all body parts for assimilation.
8. Large Intestine absorbs water and minerals from the undigested food.
9. Rectum storage point for undigested food.
10. Anus – Fecal matter removed through it.

Question 8.
What is acidity? Mention the symptoms, causes and home remedies for acidity.
Answer:
Acidity:
It’s a common problem associated with digestive track caused due to excess acids in stomach.

Symptoms :
Burning sensation in chest, stomach and in throat;
sour taste in mouth;
upper abdominal discomfort;
post meal heaviness.

Causes : consuming spicy food;
stress;
unhealthy or irregular meals;
drinking too much alcohol.

Home remedies:
Consuming butter milk, coconut water, eating of herbs such as ajwain, tulsi leaves, saunf, jeera and pudina leaves, cloves, jaggery

AP Board 7th Class Science 3rd Lesson 1 Mark Bits Questions and Answers Nutrition in Organisms

I. Multiple Choice Questions

1. Carbohydrates digest first in
A) Buccal cavity
B) Stomach
C) Small intestine
D) Large intestine
Answer:
A) Buccal cavity

2. Proteins digestion starts in
A) Buccal cavity
B) Stomach
C) Small intestine
D) Large intestine
Answer:
B) Stomach

3. Chocolates, sweets, soft drinks and other sugar products cause of
A) Acidity
B) Constipation
C) Tooth decay
D) Diarrhea
Answer:
C) Tooth decay

4. The process of intake and utilization of food by organisms is called ……
A) Digestion
B) Absorption
C) Nutrition
D) Excretion
Answer:
C) Nutrition

5. Nutrition in green plants is
A) Autotrophic
B) Saprophytic
C) Parasitic
D) Holozoic
Answer:
A) Autotrophic

6. This is not a requirement of photosynthesis
A) Oxygen
B) Carbon dioxide
C) light
D) water
Answer:
A) Oxygen

7. Product of photosynthesis
A) Oxygen
B) Water
C) Glucose
D) All the above
Answer:
D) All the above

8. Presence of starch in leaves indicates the occurrence of…..
A) Respiration
B) Photosynthesis
C) Digestion
D) Excreton
Answer:
B) Photosynthesis

9. This works as food factory of the plant
A) Stem
B) Leaf
C)Flower
D) Root
Answer:
B) Leaf

10. Function of stomata is
A) Gaseous exchange
B) Transport of water
C) Food production
D) Digestion
Answer:
A) Gaseous exchange

11. Find the correct statement
i) Nepenthes is a insectivorous plant.
ii) It grow in phosphorous deficient soils.
A) both are correct
B) i only correct
C) ii only correct
D) both are wrong
Answer:
B) i only correct

12. Example for saprophyte
A) Amoeba
B) Utricularia
C) Cuscuta
D) Bread mould
Answer:
D) Bread mould

13. Chlorophyll-containing partner in the lichens is
A) Algae
B) Fungi
C) Bacteria
D) Amoeba
Answer:
A) Algae

14. Cuscuta absorbs its food from host through
A) Tap root
B) Fibrous root
C) Haustoria
D) prop roots
Answer:
C) Haustoria

15. National Deworming Day is observed on
A) February 10
B) August 10
C) Both A & B
D) December 10
Answer:
C) Both A & B

16. Albendazole tablet is a…
A) Antibiotic
B) Antiviral drug
C) Antifungal drug
D) Deworming drug
Answer:
D) Deworming drug

17. Taking of food into the body is called…..
A) Ingestion
B) Digestion
C) Absorption
D) Egestion
Answer:
A) Ingestion

18. Conversion of food into simple soluble forms is called …
A) Ingestion
B) Digestion
C) Absorption
D) Egestion
Answer:
B) Digestion

19. Transfer of food to the blood is called …..
A) Ingestion
B) Digestion
C) Absorption
D) Egestion
Answer:
C) Absorption

20. Removal of waste products and undigested food from the body
A) Ingestion
B) Digestion
C) Absorption
D) Egestion
Answer:
D) Egestion

21. Amoeba collects its food with the help of
A) Pseudopodia
B) Nucleolus
C) Food vacuole
D) Cytoplasm
Answer:
A) Pseudopodia

22. This is not digestible in human being is …..
A) Starch
B) Protein
C) Fat
D) Cellulose
Answer:
D) Cellulose

23. Nutrition in human being is …
A) Autotrophic
B) Parasitic
C) Saprophytic
D) Holozoic
Answer:
D) Holozoic

24. The total length of alimentary canal is about
A) 3 meters
B) 6 meters
C) 9 meters
D) 12 meters
Answer:
C) 9 meters

25. Tofal number of teeth in the adult is
A) 8
B) 16
C) 20
D) 32
Answer:
D) 32

26. Teeth that help to cut the food….
A) incisors
B) canines
C) premolars
D) molars
Answer:
A) incisors

27. Hardest part of the human body is
A) Bone
B) Teeth
C) Cartilage
D) Muscle
Answer:
B) Teeth

28. The major culprits of tooth decay ….
A) Chocolates
B) Sweets
C) Soft drinks
D) All the above
Answer:
D) All the above

29. Common chamber for both digestive track and respiratory track is
A) Pharynx
B) Duodenum
C) Esophagus
D) Buccal cavity
Answer:
A) Pharynx

30. The muscular tubular structure that connects pharynx with Stomach is
A) Buccal cavity
B) Oesophagus
C) Duodenum
D) Small intestine
Answer:
B) Oesophagus

31. Hydrochloricacid in the stomach kills Bacteria in the food.
A) Lactic acid
B) Sulphuric acid
C) Acetic acid
D) Hydrochloric acid
Answer:
D) Hydrochloric acid

32. Digestion of food completes in this part
A) Stomach
B) Duodenum
C) Small intestine
D) Large intestine
Answer:
C) Small intestine

33. Digested food absorbed in to blood through
A) Stomach
B) Duodenum
C) Villi
D) Large intestine
Answer:
C) Villi

34. Large intestine absorbs….
A) Water
B) Digested food
C) Minerals
D) A & C
Answer:
D) A & C

35. Reason for acidity…
A) Stress
B) Irregular meals
C) Drinking too much alcohol
D) All the above
Answer:
D) All the above

36. The only asana that can be done on full stomach.
A) Padmaasan
B) Vajrasana
C) Bhujangasana
D) shirshaasana
Answer:
B) Vajrasana

II. Fill in the blanks

1. Liver produces …………… juice.
2. Expand NDD ……………
3.
4. The process of intake and utilization of food by organisms is called …………… .
5. The mqde of nutrition in which organisms make food by themselves is called …………… .
6. The mode of nutrition in which organisms depend on other organisms, for food is called …………… .
7. Green plants are …………… .
8. Humans and animals are directly or indirectly dependent on …………… for food.
9. …………… are the special structures present only in plant cells and absent in animal cells.
10. Chlorophyll is present in the …………… of plant cell.
11. …………… is the pigment responsible for the greenery of the plants.
12. The process-by which green plants make their own food from carbon dioxide and water by using light energy in the presence of chlorophyll is called …………… .
13. Glucose formed in photosynthesis is converted and stored in the form of …………… .
14. The presence of starch in leaves indicates the occurrence of …………… .
15. Occurrence of photosynthesis can be confirmed by testing the leaf extract with …………… solution.
16. …………… work as “food factories of plants”.
17. …………… captures the energy of the sunlight.
18. …………… is the source of energy in the process of photosynthesis.
19. …………… is the ultimate source of energy for all living organisms.
20. Gaseous exchange occurs in the leaves through …………… .
21. …………… is the gas required for photosynthesis.
22. …………… is the gas produced in photosynthesis.
23. Nutrients needed ip minute quantities are called …………… .
24. Insectivorous plants meet their requirements from insects.
25. Saprophytes grow on …………… .
26. The mode of nutrition in which organisms take in nutrients in the form of solution from dead and decaying matter is called …………… nutrition.
27. …………… play key role in cleaning,up the earth surface.
28. Chlorophyll-containing partner in lichen is
29. An association between two organisms for food in which one organism get benefited and other is vitiated is called ……………
30. The organism that get benefited in parasitism is …………… .
31. Organism on which parasite is growing is called …………… .
32. …………… is the mode of heterotrophic nutrition in which the food is taken in solid or liquid form from the outside and is digested inside the body.
33. Pseudopodia are food collecting, organs in …………… .
34. Humans cannot digest …………… .
35. The digestive system consists Of the …………… and …………… .
36. The total length Of alimentary canal is about …………… meters.
37. Teeth in the human beings are of …………… types.
38. …………… is the hardest part of the human body.
39. …………… is the only asana that can be done on full stomach.
40. Damage of teeth due to acids is called …………… .
41. Carbohydrate digestion starts in …………… .
42. …………… is the common chamber for both digestive track and respiratory track.
43. Proteins digestions starts in the …………… .
44. …………… in the stomach kills Bacteria in the food.
45. Inner wall of the small intestine have thousands of finger-like outgrowths called …………… .
46. Villi absorb the …………… .
47 …………… absorbs water and minerals from the undigested food.
48. …………… is the storage;point for undigested food.
49. Fecal matter removed through …………… .
Answer:

1. bile
2. National Deworming Day
3. carbondioxide, oxygen
4. nutrition
5. autotrophic nutrition
6. heterotrophic nutrition
7. autotrophs
8. plants
9. Chloroplasts
10. chloroplast
11. Chlorophyll
12. Photosynthesis
13. starch.
14. photosynthesis
15. Iodine
16. Leaves
17. Chlorophyll
18. Sunlight
19. Sun
20. stomata.
21. Carbon dioxide
22. Oxygen
23. micronutrients
24. nitrogen
25. dead and decaying matter
26. saprophytic
27. Saprophytes
28. algae
29. parasitism.
30. parasite
31. host
32. Holozofc Nutrition
33. amoeba
34. cellulose
35. Tooth
36. Vajrasana
37. tooth decay
38. buccal cavity
39. Pharynx
40. stomach
41. Hydrochloric acid
42. villi.
43. digested food
44. Large Intestine
45. Rectum
46. anus.

III. Match the following

1.

Group – A	Group – B
A) Ingestion	1) Transfer of food to the blood.
B) Digestion	2) Absorbed food became the part of the body
C) Absorption	3) Preparing food inside the body
D) Assimilation	4) Removal of undigested food from the body.
E) Egestion	5) Conversion of food into simple soluble forms.
	6) Food is taken into the body.

Answer:

Group – A	Group – B
A) Ingestion	6) Food is taken into the body.
B) Digestion	5) Conversion of food into simple soluble forms.
C) Absorption	3) Preparing food inside the body
D) Assimilation	2) Absorbed food became the part of the body
E) Egestion	4) Removal of undigested food from the body.

2.

Group – A	Group – B
A) Autotrophs	1) Mouth
B) Saprophytes	2) Special roots
C) Parasite	3) Chlorophyll
D) Holozoic	4) Solution

Answer:

Group – A	Group – B
A) Autotrophs	3) Chlorophyll
B) Saprophytes	4) Solution
C) Parasite	2) Special roots
D) Holozoic	1) Mouth

3.

Group – A	Group – B
A) Buccal cavity	1) Removes fecal matter
B) Stomach	2) Absorbs water and minerals
C) Small intestine	3) Starts carbohydrate digestion
D) Large intestine	4) Preparing food inside the body.
E) Anus	5) Starts protein digestion
	6) Complete the digestion of food

Answer:

Group – A	Group – B
A) Buccal cavity	3) Starts carbohydrate digestion
B) Stomach	5) Starts protein digestion
C) Small intestine	6) Complete the digestion of food
D) Large intestine	2) Absorbs water and minerals
E) Anus	1) Removes fecal matter

4.

Group – A	Group – B
A) Utricularia	1) Ruminants
B) Venus fly trap	2) Others
C) Cuscuta	3) Bladderwort
D) Cows	4) Nourishment
E) Trophos	5) Dionaea
	6) Dodder plant

Answer:

Group – A	Group – B
A) Utricularia	3) Bladderwort
B) Venus fly trap	5) Dionaea
C) Cuscuta	6) Dodder plant
D) Cows	1) Ruminants
E) Trophos	4) Nourishment

Do You Know?

→ Forests are green in colour. Isn’t it? Infact they are green as they have many trees. Trees are green as they have leaves. Leaves are green as they have chloroplasts. Chloroplasts are the special structures present only in plant cells and absent in animal cells.These chloroplasts consists of a green coloured pigment called chlorophyll in them,. This chlorophyll is responsible for all this greenery and play key role in preparation of food. You will learn about all these in your higher classes.

→ There are some plants that eat insects. Being green in colour, they can manufacture their own food. But as they grow in areas deficient in Nitrogen, they meet their Nitrogen requirements from insects. Leaves of these plants are specially modified to trap insects. Nepenthes, (pitcher plant) Droseras, Utricularia (bladderwort), Dionaea (Venus fly trap) are examples of some such insectivorous plants. These are also called as carnivorous plants.

→ Some plants of the Dal family (legume plants) possess a type of bacteria growing on their roots in nodules. The bacteria fixes nitrogen for the plant while it gets shelter in the roots of these plants. Such an association is beneficial to both groups and is called Symbiosis.

In organisms called lichens (litmus paper is obtained from lichens), a chlorophyll-
containing partner, which is an algae and a fungus live together. The fungus provides shelter, water and minerals to the algae and in return, the algae provides food for the fungus.

→ Every year February 10 and August 10 is observed as the National Deworming Day(NDD). The day aims at eradicating intestinal worms among children in the age group of 1-19 years. On this day. Albendazole tablet (deworming drug) is administered to children.

Digestion In Grass Eating Animals

→ Have you observed cows, buffaloes and other grass eating animals chewing continuously even when they are not eating? They have four chambers in stomach. They are rumen, reticulum,omasum and abomasum. Actually they quickly swallow the grass and store it in a, part of the stomach called rumen. In rumen, food gets partially digested and is called cud. But later the cud returns to the mouth in small lumps and animal chews it again. This process is called rumination and these animals are called ruminants.

The, grass is rich in cellulose, a type of carbohydrate. In ruminants, the cellulose of the food is digested by the action of certain bacteria present in the rumen of grass eating animals.Many animals including humans cannot digest cellulose due to the absence of such bacteria.

→ Normally Bacteria present in our mouth are not harmful to us. If we do not clean our teeth and mouth after eating, many harmful bacteria begin to live and grow in it. These bacteria breakdown the sugars present from leftover food and release acids. These acids gradually damage teeth. This is called tooth decay. If it is not treated in time, it causes severe toothache and in extreme cases results in tooth loss. Chocolates, sweets, soft drinks and other sugar products are the major causes of tooth decay

→ Vajrasana increases flow of blood into our stomach area, thus improving our bowel movements and relieving constipation. It also keeps us to get rid of gas and acidity. It is the only asana that can be done on full stomach.

These AP 7th Class Science Important Questions 2nd Lesson Nature of Substances will help students prepare well for the exams.

AP Board 7th Class Science 2nd Lesson Important Questions and Answers Nature of Substances

Question 1.
From which language does the word ‘Acid’ derived?
Answer:
The word acid came from the Latin word ‘acere’ means sour.

Question 2.
Give some examples for substances containing acids.
Answer:
Tamarind, Lemon, Tomato, Apple, Curd, Raw mango etc.

Question 3.
What is the chemical name of vitamin C?
Answer:
The chemical name of vitamin C is Ascorbic acid.

Question 4.
Name some substance in which vitamin C is available.
Answer:
Vitamin C is available in citrus fruits and in amla (usiri).

Question 5.
What will happen when carbon dioxide is added to water?
Answer:
When carbon dioxide is added to water, it become carbonic acid/soda.

Question 6.
How are bases to touch?
Answer:
Bases are slippery to touch.

Question 7.
Which base is used to prepare bath soap?
Answer:
Bath soap is prepared using potassium hydroxide.

Question 8.
Which base is used to prepare detergent soap?
Answer:
Detergent soap for washing clothes is prepared using Sodium hydroxide.

Question 9.
What are the main components in the tooth paste?
Answer:
Main components in the tooth paste are calcium carbonate, aluminum hydroxide and sodium bi carbonate. All these chemicals are bases.

Question 10.
What are alkalis?
Answer:
Bases that can dissolve in water are called alkalis.

Question 11.
Give some examples for alkalis.
Answer:
Some examples of alkalis are sodium hydroxide, potassium hydroxide and calcium hydroxide.

Question 12.
What are neutral substances?
Answer:
The substance which is neither an acid nor a base is known as neutral substance.

Question 13.
Give examples for neutral substances.
Answer:
Distilled water, salt solution, sugar solution etc are example for neutral substances.

Question 14.
Who gave the most modern definition of acids and alkalis?
Answer:
Svante Arrhenius Swedish physical chemist gave the most modern definition of acids and alkalis.

Question 15.
What are indicators?
Answer:
Substances which are used to test acids or bases are called acid base indicators.

Question 16.
From what does litmus extracted?
Answer:
Litmus is extracted from lichens.

Question 17.
What are olfactory indicators?
Answer:
Substances which change their smell when mixed with acid or base are known as olfactory indicators. Ex: onion, vanilla and clove oil.

Question 18.
What happens when a metal piece is dropped in an acid?
Answer:
If you drop a metal piece in an acid it reacts with acid and releases hydrogen gas.

Question 19.
How can you test hydrogen gas?
Answer:
Hydrogen gas make the flair e to put off with a pop sound.So we can test it by introduc¬ing a incense stick into the mouth of the container having gas.

Question 20.
Why does balloon fill with hydrogen gas fly?
Answer:
Hydrogen gas has less weight than air. So balloon fill with hydrogen gas flies high.

Question 21.
How can you test carbon dioxide gas?
Answer:
Carbon dioxide gas put off the fire. So we can test it by introducing a lighting match stick into the mouth of the container having gas.

Question 22.
What is neutralization reaction?
Answer:
Reaction of an acid and a base is called neutralization reaction.

Question 23.
What are the substances formed in neutralization reaction?
Answer:
The substances formed in neutralization reaction are water and salt.

Question 24.
What do antacids contain?
Answer:
Antacids contain bases, eg: aluminum hydroxide, milk of magnesia.

Question 25.
Why do we get pain and itching, when an ant bites us?
Answer:
When an ant bites us, it injects formic acid into our skin. It causes pain and itching.

Question 26.
What is Acid rain?
Answer:
Rain water with slight acidic nature is called Acid rain.

Question 27.
All alkalis are bases but all bases are not alkalis. Give one example in support of this statement.
Answer:
Zinc hydroxide is a base but not an alkali. It doesn’t dissolve in water.

7th Class Science 2nd Lesson Nature of Substances Short Questions and Answers

Question 1.
Mention some food items containing acids and write the name of the acid present in them.
Answer:

Food item	Acid present
Lemon	Citric acid
Tamarind	Tartaric acid
Apple	Malic acid
Tomato	Oxalic acid
Amla	Ascorbic acid

Question 2.
What are mineral acids? Give examples.
Answer:

1. Some acids are prepared artificially from minerals which are extracted from the earth. Such acids are known as mineral acids or synthetic acids.
2. Hydrochloric acid, sulphuric acid and nitric acids are examples for mineral acids.

Question 3.
Mention any four daily life situations where acids are being used.
Answer:

1. Hydrochloric acid is used for bath room cleaning.
2. Sulphuric acid is used in batteries.
3. Soda water and cool drinks contain carbonic acids.
4. Fatty acids are used in manufacturing of soaps.
5. Citric acid, tartaric acid, acetic acid etc, are used in the preparation and preserva¬tion of some foods.

Question 4.
Mention any four daily life situations where bases are being used.
Answer:

1. Bath soap is prepared using potassium hydroxide.
2. Detergent soap for washing clothes is prepared using Sodium hydroxide.
3. Aluminium hydroxide is used in the preparation of tooth paste.
4. Aluminium hydroxide and milk of magnesia are used in preparation of antacids.
5. Quick lime and Potassium hydroxide are used to treat acidic soils.

Question 5.
Is it possible to test all the acids and bases simply by tasting or touching them? Why?
Answer:

1. No, It is not possible to test all the acids and bases simply by tasting or touching them.
2. Some acids like hydrochloric acid, sulphuric acid, nitric acids and bases like so¬dium hydroxide, potassium hydroxide are very harmful and strong.
3. We cannot test them by touch or taste.
4. We should use indicators to test them.

Question 6.
How to prepare turmeric indicator?
Answer:

1. Take a table spoon of turmeric powder in a plate.
2. Add little water and make it into a paste.
3. Take a white paper and apply the paste over it on both sides and let it dry.
4. After drying, cut the paper into strips.
5. Now turmeric paper strips are ready for use as indicator.

Question 7.
Do the turmeric strip act as a indicator? How?
Answer:

1. Yes, turmeric strip act as a indicator.
2. This is because turmeric is a natural indicator.
3. The colour of turmeric strip will change into reddish brown in basic solutions.
4. It remain yellow in acidic solutions.

Question 8.
How can you identify acids and bases using hibiscus indicator?
Answer:

1. Hibiscus is a natural indicator that changes its colour in acids and bases.
2. It changes its colour from violet to pink in acids.
3. It changes its colour from violet to green in bases.
4. Thus it can be used to identify acids and bases.

Question 9.
Mention the colours of different indicators in acidic and basic mediums.
Answer:

Indicator	In acid	In base
1. Blue litmus	Red	–
2. Red litmus	–	Blue
3. Methyl orange	Red	Yellow
4. Phenolphthalein	–	Pink
5. Turmeric	–	Reddish brown
6. Hibiscus	Pink	Green

Question 10.
Magicians bring blood out of a lemon when they cut it with a knife. How is it pos-sible?
Answer:

1. It is simply a science trick.
2. Magician prepares a knife by applying an indicator like methyl orange or hibiscus solution on it.
3. Then he cut the lemon before us.
4. Due to the reaction the lemon juice (acid) turns red and we are made to believe that blood is coming out of the lemon.

Question 11.
Who introduced pH scale? How is it used?
Answer:

1. pH scale was introduced by Sorensen.
2. Strength of acid or base solution is measured in pH scale.
3. The range of pH scale is from 0 to 14.
4. pH of acids is less than 7, pH of bases is more than 7 and pH of neutral substance is 7.
5. Strength of acids decreases from 0 to 7 and strength of bases increases from 7 to 14.

Question 12.
Classify the following in to strong acid, weak acid, strong base, weak base.
Hydrochloric acid, Acetic acid, oxalic acid, Sodium hydroxide, Sulphuric acid, Po-tassium Hydroxide, Nitric acid, Ammonium hydroxide,Citric acid.
Answer:

Question 13.
Pickles are not stored in aluminum or steel or copper vessels. Why?
Answer:

1. Pickles contain acids.
2. These acids react with metal containers and releases toxic substances.
3. So, we should store them in metal containers.
4. Generally, they are stored in ceramic or glass containers which do not react.

Question 14.
How can you prove carbon dioxide releases when acid reacts with calcium carbonate?
Answer:

1. Take some crushed egg shells in a test tube and pour dilute sulphuric acid until the egg shells completely sink. Egg shell is made of calcium carbonate.
2. We will observe that a gas being released.
3. Bring a lighting match stick near the mouth of test tube.
4. The gas that put off the lighting match stick indicating that the gas is carbon diox¬ide.
5. This confirms that carbon dioxide releases when acid reacts with calcium carbon¬ate.

Question 15.
What is neutralization? Give examples for neutralization reaction from day-to-day life.
Answer:

1. Neutralization is a chemical reaction where acid and base react with each other to form salt and water.
2. The bases in the antacids neutralize gastric juice and give us relief from acidity.
3. When an ant bites, it injects formic acid into the skin. It causes pain and itching. We can neutralize the acid by rubbing the paste of baking soda on the place of bite. Baking Soda is a base and it neutralizes the formic acid.
4. When soil becomes too acidic, farmers neutralize it by adding basic substances like quick lime (sunnam), potassium hydroxide etc,.
5. When soil becomes too basic they neutralize it with organic substances like com¬post which release acidic substances into the soil.

Question 16.
What is acid rain? How is it caused?
Answer:

1. Rain water with slight acidic nature is called Acid rain.
2. Air pollution is a major cause of acid rains.
3. Fuels like coal and petroleum emissions have sulphur dioxide and nitrogen dioxide etc. which react with rain water droplets and form sulphuric acid and nitric acid.
4. These acids come along with rain water to cause acid rain.

Question 17.
Bhasker said that some plants help us to find out the nature (pH)of the soil. Do you support his statement?
Answer:

1. Yes, I support his statement.
2. Hydrangea plants have different colours of flowers based on the pH of the soil.
3. If the pH of the soil is below 5.5 it gives blue flowers.
4. If the pH of the soil is below 6.5 it gives pink flowers.
5. Thus, they helps us to find the nature (pH) of soil.

Question 18.
Why do Neem/ miswak/ kanuga sticks are used as chew sticks from olden days?
Answer:

1. Neem, miswak, kanuga sticks are used as chew sticks (pandupulla) from olden days.
2. Because they have basic substances.
3. The bases in these sticks neutralizes the acids released by the bacteria in our mouth.
4. Thus they protect our oral health.

Question 19.
Write some acids and there uses in our daily life in the form of a table.
Answer:

Name of the acid	Uses
Vinegar (Acetic acid)	Preservation of pickles and other food substances
Citric acid	Food preservation and in soft drinks
Nitric acid and sulphuric acid	Manufacture of chemical fertilizers, paints,  dyes etc.
Sulphuric acid	Automobile battery
Tannic acid	Production of ink and leather

Question 20.
Write some bases and their uses in our daily life in the form of a table.
Answer:

Name of the Base	Uses
Calcium hydroxide	neutralize the acidity of soil, white washing
Magnesium hydroxide (milk of magnesia)	antacid and laxative
Ammonium hydroxide Sodium hydroxide	windows cleaner, cleaning agent manufacturing of paper, soaps and detergent
Potassium hydroxide	manufacturing of soaps and batteries

Question 21.
What is soap? How is it prepared?
Answer:

1. Soap is a salt with basic nature.
2. It is prepared by adding fatty acids like coconut oils to alkalis like Sodium hydroxide or Potassium hydroxide.
3. Detergent soap used to wash cloths contains Sodium hydroxide.
4. Bath soap contains Potassium hydroxide.

Question 22.
What are the precautions to be taken while handling chemicals?
Answer:

1. Do not taste and smell. Do not let it fall on the body.
2. Use a dropper while transferring acid from bottle.
3. While adding water to make dilution, pour small quantities of acid slowly into water taken in a beaker.
4. Use a holder to hold a test tube.
5. Read the precautions given on the containers of substances.

Question 23.
What precautions should be taken if the body burns due to chemicals?
Answer:

1. Start first aid immediately.
2. Remove contaminated clothes from the person.
3. Wash the affected area with plenty of water.
4. Don’t pierce the blisters.
5. Shift the person to hospital.

7th Class Science 2nd Lesson Nature of Substances Long Questions and Answers

Question 1.
Write the properties of Acids.
Answer:

1. Acids are sour to taste.
2. They turn blue litmus to red colour, methyl orange to red colour, hibiscus indicator to pink colour.
3. They don’t change the colour of phenolphthalein and turmeric indicators.
4. pH of acids is less than 7.
5. Acids react with metals and release hydrogen gas.
6. Acids react with calcium carbonate to release carbon dioxide.
7. Acids react with base to form water and salt. This reaction is called neutralisation reaction.
8. Hydrochloric acid, sulphuric acid and nitric acid are examples for acids.

Question 2.
Write the properties of Bases.
Answer:

1. Bases are bitter to taste.
2. They are slippery to touch.
3. They turn red litmus to blue colour, methyl orange to yellow colour, phenolphtha- lein to pink and hibiscus indicator to green colour.
4. They change the colour of turmeric indicator to reddish brown.
5. pH of acids is more than 7.
6. Bases like sodium hydroxide react with metals and releases hydrogen gas.
7. Bases react with acid to form water and salt. This reaction is called neutralisation reaction.
8. Sodium hydroxide, magnesium hydroxide, potassium hydroxide and calcium hy-droxide are examples for bases.

Question 3.
How can you demonstrate the neutralisation reaction in the laboratory?
Answer:
Aim: To demonstrate the neutralisation reaction.

What you need:
1) Conical flask, 2) Dropper, 3) Sodium hydroxide solution, 4) Hydro-chloric acid, 5) Phenolphthalein indicator

How to do:
Take sodium hydroxide solution in a conical flask and observe its colour. Now add 2-3 drops of phenolphthalein indicator to it. Now observe the colour. It is pink in colour. Using a dropper add dilute hydrochloric acid drop by drop to this solution, and stir gently.

What you see:
The pink colour of the solution disappears. On crystallisation water evaporates from this solution leaving the salt in the flask.

What you learn:
In this reaction acid and base reacts with each other to form salt and water. Such reactions are called neutralisation reactions.
Hydrochloric acid + sodium hydroxide → sodium chloride + water

Question 4.
Take the following solutions in to test tubes. Test them with a) red litmus, b) blue litmus, c) methyl orange and d) phenolphthalein indicators. Tabulate your results. 1)Dilute hydrochloric acid, 2) Sodium hydroxide, 3) Acetic acid, 4) Salt solution, 5) Sugar solution and 6) Soap water
Answer:

Question 5.
How can you prove that hydrogen gas releases when acid reacts with metals?
(or)
How can you produce hydrogen gas in the laboratory?
Answer:
Aim: Acid reacts with metals and produces hydrogen gas.

Materials required:
Conical flask, hydrochloric acid, zinc pieces, incense stick, match box.

Procedure:
Take 5g of zinc metal pieces in a conical flask. Pour 20 ml of dilute hydro-chloric acid into it. Now, observe what happens.

Observation:
The zinc pieces reacted with the hydrochloric acid and releases a gas. Test for hydrogen gas

Now, introduce a incense stick into mouth of the conical flask. The flame of burning stick will put off with a pop sound. This is a test for hydrogen gas. Hydrochloric acid reacts with zinc metal and forms zinc chloride, releases hydrogen gas. This reaction can be written as a word equation,
Zinc + hydrochloric acid → zinc chloride + hydrogen

Conclusion:
Hence, we can conclude that acids react with metals and release hydrogen gas.

AP Board 7th Class Science 2nd Lesson 1 Mark Bits Questions and Answers Nature of Substances

I. Multiple Choice Questions

1. Table salt contains
A) Sodium chloride
B) Sodium bicarbonate
C) Potassium chloride
D) Sodium hydroxide
Answer:
A) Sodium chloride

2. Baking soda contains
A) Sodium chloride
B) Sodium bicarbonate
C) Potassium chloride
D) Sodium hydroxide
Answer:
B) Sodium bicarbonate

3. Gastric juice means
A) Sulphuric acid
B) Citric acid
C) Antacid
D) Hydrochloric acid
Answer:
D) Hydrochloric acid

4. Sulphuric acid reacts with eggshell and releases
A) Carbondioxide
B) Hydrogen
C) Oxygen
D) None
Answer:
A) Carbondioxide

5. Substance/s formed in a neutralization reaction is/are
A) Water
B) Salt
C) A and B
D) Hydrogen
Answer:
C) A and B

6. Which of the following does not contain acid?
A) lemon
B) Bitter gourd
C) Amla
D) Tomato
Answer:
B) Bitter gourd

7. This acid is present in cool drinks
A) Sulphuric acid
B) Hydrochloric acid
C) Carbonic acid
D) Vinegar
Answer:
C) Carbonic acid

8. Bath soap is prepared using
A) Sodium hydroxide
B) Aluminum hydroxide
C) Calcium carbonate
D) Potassium hydroxide
Answer:
D) Potassium hydroxide

9. Olfactory indicator from the following
A) Hibiscus
B) Phenolphthalein
C) Clove oil
D) Methyl orange
Answer:
C) Clove oil

10. lichens are used in the preparation of
A) Litmus
B) Methyl blue
C) Phenolphthalein
D) Olfactory indicators
Answer:
A) Litmus

11. Phenolphthalein shows colour change with
A) Acids
B) Bases
C) both A & B
D) Neutral substances
Answer:
B) Bases

12. Which of the following is a strong acid?
A) Citric acid
B) Acetic acid
C) Sulphuric acid
D) Malic acid
Answer:
C) Sulphuric acid

13. This gas is lighter than air
A) Hydrogen
B) Nitrogen
C) Oxygen
D) Carbon dioxide
Answer:
A) Hydrogen

14. Product of neutralisation
A) Salt
B) Water
C) Both A & B
D) Acid
Answer:
C) Both A & B

15. Example for salt
A) Common salt
B) Antacid
C) Tooth paste
D) Clove oil
Answer:
A) Common salt

16. Acid produced in stomach
A) Sulphuric acid
B) Hydrochloric acid
C) Nitric acid
D) Carbonic acid
Answer:
B) Hydrochloric acid

17. This can be used to treat ant bite
A) Baking soda
B) Common salt
C) Vinegar
D) Turmeric
Answer:
A) Baking soda

18. pH of bases
A) 0-14
B) 7
C) more than 7
D) less than 7
Answer:
C) more than 7

19. This is responsible for acid rains
A) Sulphur dioxide
B) Nitrogen dioxide
C) Both A & B
D) Oxygen
Answer:
C) Both A & B

20. Flowers that change their colour according to the nature of soil
A) Hydrangea
B) Marigold
C) Hibiscus
D) Jasmine
Answer:
A) Hydrangea

II. Fill in the blanks.

1. Rain with slight ………….. nature is called acid rains.
2. Wash the affected burning area on skin with ………….. .
3. ………….. will be prepared by adding fatty acids to alkalis.
4. ………….. are used in making soaps.
5. ………….. are used to test the nature of substances.
6. ………….. acid is also called as Vitamin C.
7. ………….. acid is used for bath room cleaning.
8. ………….. acid is used in batteries.
9. Soda water and cool drinks contain ………….. acids.
10. Bases are ………….. to taste.
11. Bath soap is prepared using ………….. .
12. Detergent soap is prepared using
13. Bases that can dissolve in water are called ………….. .
14. The substance which is neither an acid nor a base is known as ………….. .
15. Purewater is a ………….. substance.
16. Substances which are used to test acids or bases are called ………….. .
17. Indicators obtained from natural sources are called as ………….. .
18. The most commonly used natural indicator is ………….. .
19. The colour of turmeric strip will change into ………….. in soap water.
20. Soda water turns into ………….. on adding hibiscus indicator.
21. Soap solutions turns ………….. on adding hibiscus indicator.
22. An indicator prepared from artificialsources is known as ………….. .
23. Methyl orange turns in acids and ………….. in bases.
24. Phenolphthalein turns ………….. in bases, but ………….. in acids.
25. Substances which change their smell when mixed with acid or base are known as ………….. .
26. ………….. is a mixture of different indicators and shows different colours in different solutions.
27. ………….. can show the strength of acid or alkaline substance.
28. Strength of acid or base solution is measured in ………….. scale.
29. pH of acids is ………….. .
30. pH of bases is ………….. .
31. pH of neutral substance is ………….. .
32. Natural acids are ………….. acids.
33. Acids react with metals and release gas.
34. Acids react with ………….. and release carbon dioxide gas.
35. Reaction of an acid and a base is called ………….. reaction.
36. The substances formed in neutralization reaction are ………….. and ………….. .
37. Antacids contain ………….. .
38. When an ant bites, it injects acid into the skin.
39. When soil becomes too acidic, farmers treat it by adding
40. When soil becomes too basic,farmers treat it with
41. Rain water with slight acidic nature is called
42. ………….. acid is used in the preservation of pickles and other food substances.
43. ………….. acid is used in the production of ink and leather.
44. Base used in windows cleaner is ………….. .
45. Magnesium hydroxide is used in ………….. and ………….. .
Answer:

1. acidic
2. plenty of water
3. Soap
4. Bases
5. Indicators
6. Ascorbic
7. Hydrochloric
8. Sulphuric
9. carbonic
10. bitter
11. potassium hydroxide
12. Sodium hydroxide
13. alkalis
14. neutral substance
15. Neutral
16. acid base indicators
17. Natural indicators.
18. litmus
19. reddish brown
20. pink
21. green
22. Synthetic indicator.
23. red, yellow
24. pink, does not change
25. olfactoryin dicators.
26. Universal indicatoris
27.  Universal indicator
28. pH
29. less than 7
30. more than 7
31. 7
32. weak
33. hydrogengas.
34. calcium carbonate
35. neutralization reaction.
36. water, salt
37. bases.
38. formic
39. quick lime/ potassium hydroxide.
40. compost.
41. Acid rain.
42. Acetic
43. Tannic
44. Ammonium hydroxide
45. antacid and laxative

III. Match the following

1.

Group – A	Group – B
A) Blue litmus in acid	1) Yellow
B) Methyl orange in base	2) No change
C) Hibiscus in acid	3) Red
D) Phenolphthalein in acid	4) Brown
E) Turmeric in base

Answer:

Group – A	Group – B
A) Blue litmus in acid	3) Red
B) Methyl orange in base	1) Yellow
C) Hibiscus in acid	5) Pink
D) Phenolphthalein in acid	2) No change
E) Turmeric in base	4) Brown

2.

Group – A	Group – B
A) Hydrangea plants	1) Air pollution
B) Neem	2) pH of the soil
C) pH scale	3) Chew sticks
D) Nitric acid	4) Manufacture of fertilizers
E) Acid rain	5) Automobile battery
	6) Sorensen

Answer:

Group – A	Group – B
A) Hydrangea plants	2) pH of the soil
B) Neem	3) Chew sticks
C) pH scale	6) Sorensen
D) Nitric acid	4) Manufacture of fertilizers
E) Acid rain	1) Air pollution

3.

Group – A	Group – B
A) Antacid	1) Formic acid
B) Ant	2) Salt and water
C) Neutralisation	3) Bases that can dissolve in water
D) Olfactory indicator	4) Stomach
E) Alkalis	5) Hibiscus
	6) Clove oil

Answer:

Group – A	Group – B
A) Antacid	4) Stomach
B) Ant	1) Formic acid
C) Neutralisation	2) Salt and water
D) Olfactory indicator	6) Clove oil
E) Alkalis	3) Bases that can dissolve in water

Do You Know?

Arrhenius
→ Svante Arrhenius Sweadish physical chemist gave the most modern definition of acids and alkalis. He got Noble prize in 1903 for his contribution in chemistry.

BLOOD IN LEMON…!
→ You might have seen the trick by magicians … blood coming out from a lemon when cut with a knife. This is made possible by applying an indicator like Methyl orange or hibiscus flower solution on the knife before cutting the lemon. The indicator reacts with lemon juice to give out red coloured juice. Next time you see such a trick reveal the secret.

→ Hydrangea plants have different colours of flowers based on the pH of the soil. If the pH of the soil is below 5.5 it gives blue flowers. If the pH of the soil is below 6.5 it gives pink flowers. This may helps us to find the nature of soil.

→ Neem, miswak, kanuga sticks are used as chew sticks (pandu pulla) from olden days.
Do you know why? Because they have basic substances. The bases in these sticks neutralizes the acids released by the bacteria in our mouth.

→ Soap is a salt with basic nature. It is prepared by adding fatty acids like cocohut oils to alkalis like Sodium hydroxide or Potassium hydroxide. Detergent soap is used to wash cloths contains Sodium hydroxide where as bath soap contains Potassium hydroxide. Zinc hydroxide is a. base but not an alkali. This is used in cosmetic products. All alkalis are bases but all bases are not alkalis. Discuss with your friends.