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These AP 7th Class Science Important Questions 12th Lesson Soil and Water will help students prepare well for the exams.

AP Board 7th Class Science 12th Lesson Important Questions and Answers Soil and Water

Question 1.
What are the most important resources for the living things?
Answer:

1. The soil and water are the most important resources for living things.
2. There is no life without these resources.

Question 2.
What is soil? Name the branch of science that deals with the scientific study of soil?
Answer:

1. The upper most layer of earth’s crust is known as soil.
2. The scientific study of soil is called “Pedology”.

Question 3.
Why soil is so important for plants?
Answer:

1. Soil is a substratum in which plants get nutrients.
2. Soil is a habitat for plants and many animals.

Question 4.
What is the pleasant smell after rain is known as? Mention the reason for the pleasant smell of soil after rain?
Answer:

1. The pleasant smell after the rain is known as ‘Petrichor scent’.
2. It is because of the rising of a substance called geosmin from the soil into the air when it rains.
3. It is produced by the spores of actinomycetes bacteria.

Question 5.
Why soil is an important resource?
Answer:

1. Human beings depend on soil for their basic needs.
3. It has become an important part of our life.

Question 6.
What is Pedogenesis?
Answer:
The process of formation of soil from the parent rock by the process of weathering is called pedogenesis.

Question 7.
What is humus?
Answer:

1. Dead and decayed organic matter that mixes with soil is called humus.
2. Humus levels in the soil indicates the soil fertility.

Question 8.
What are the components of soil?
Answer:
The following are the components of soil.
1) Water , 2) air , 3) organic matter, 4) inorganic matter, 5) living organisms.

Question 9.
What is Edophology? What are edaphic factors?
Answer:

1. The science dealing with the influence of soil on organisms, especially on plants is called Edophology.
2. The factors that contribute to soil composition are called edaphic factors.

Question 10.
What is soil profile?
Answer:

1. The sequence of horizontal and various components, layers of soil at a place is called soil profile.
2. Each layer has a distinct colour, texture, depth and chemical composition. These layers are called horizons.

Question 11.
What are the crops grown in black soils?
Answer:
Farmers grow paddy, sugarcane and cotton crops in black soils.

Question 12.
Mention the crops grown in loamy soils?
Answer:
Most of the farmers practice aquaculture and grow flowers, vegetables, millets, tobacco and fruits.

Question 13.
What are the crops grown in Sandy soils?
Answer:

1. Farmers grow groundnuts and castor in some places.
2. Cotton, red’gram and tomatoes are also grown in sandy soils of Chitoor.

Question 14.
What are the crops grown in black soils with light clay?
Answer:

1. Farmers mostly grow cotton and chillies in black soils which have light clay.
2. These soils can be seen in Kadapa.

Question 15.
What are the crops grown in the loamy soils of Kurnool?
Answer:

1. Farmers grow paddy, jowar and bengal gram.
2. These loamy soils of Kurnool consists of sand also.

Question 16.
Name the crops grown in red sandy soils of Visakhapatnam?
Answer:
Farmers grow crops such as cashew, sugafedne arid paddy.

Question 17.
When do we celebrate the world water day?
Answer:
We celebrate the world water day on 22nd of March.

Question 18.
What is “Water Action Decade”? What is it’s aim?
Answer:

1. Recognizing the growing challenges of water scarcity UNO launched the Water Action Decade – 2018 to 2028 on 22nd March, 2018.
2. It’s aim is to mobilize action that will help and transform our views of management of water.

Question 19.
What happens if sewage and water from industries contaminate the water resources?
Answer:

1. Sewage contains the soluble and insoluble organic and inorganic impurities and disease causing microorganisms.
2. If this contaminated water mix up with drinking water it causes diseases such as diarrhoea, cholera, dysentery, typhoid and hepatitis.

Question 20.
How can we prevent contamination of water resources?
Answer:
Contamination of water resources can be prevented by treating sewage water properly before releasing it into water resources.

Question 21.
What would happen if same crop is cultivated continuously in the same field?
Answer:

1. It decreases the soil fertility.
2. Yield decreases in the next crop.

Question 22.
Write a short note on modern water purifiers?
Answer:

1. Modern water purifiers have a filtet unit and facilities to let the ultra-violet rays to pass through.
2. Ultra-violet rays are used instead of chlorine treatment to kill the germs.

Question 23.
Why should we use clay idols instead of idols made of plaster of paris?
Answer:

1. During festivals like Vinayaka Chavithi we use idols of Ganesh made of plaster of paris and chemical colours which causes severe damage to our environment.
2. Instead of these chemical idols we should use clay idols and celebrate festivals in an ecofriendly way.

Question 24.
For which purposes are we using fresh water?
Answer:
Fresh water has been the constant and essential companion of human beings throughout history. Water is used in great quantities in agriculture and industries.

Question 25.
Which type of soil is suitable for growing cotton?
Answer:

1. Black soil is suitable for growing cotton.
2. Black soil is sticky in nature. It retains water for a long time.
3. This soil is suitable for the growth of cotton, sugarcane and paddy.

Question 26.
Which type of soil is generally seen in our state?
Answer:
In our state we see the following types of soils.
а) Black soil b) Red soil c) Red sandy soil d) Alluvial soil e) Loamy Soil

7th Class Science 12th Lesson Soil and Water Short Questions and Answers

Question 1.
Soil is useful for us in many ways. What are they?
Answer:

1. Soil is needed for agriculture.
2. It is needed for construction of buildings.
3. It is needed for extraction of minerals from mines.
4. oil is very useful for making utensils and pottery.
5. For making toys and idols soil is useful.
6. Multani soil is used in making cosmetics.

Question 2.
Mention the different horizons in soil profile?
Answer:

1. O horizon (Surface litter)
2. A horizon (Top soil)
3. B horizon (Sub soil)
4. C horizon (Regolith)
5. R horizon (Bedrock)

Question 3.
What types of soils are there in your village?
Answer:

1. Types of soil differ from village to village.
2. For guidance a village in Krishna District is identified and details are given here.
3. There is black soil in the village. This soil can retain water for a long time.
4. Here farmers grow cotton, sugarcane and paddy.

Question 4.
What is weathering?
Answer:

1. In nature due to the action of various natural agents such as wind, water, sun and climate the bigger rocks (Parent rock) gradually breakdown and give small particles which forms the soil.
2. The process of formation of soil due to natural agents like wind, water and sunlight is called weathering.

Question 5.
What are the common soil problems tested at soil testing centres?
Answer:
The common soil problems tested at soil testing centres include :

1. Low organic matter like carbon
2. Available minerals in soil – nitrogen, phosphorus and potassium.
3. Availability of micro nutrient levels
4. Poor drainage
5. Soil temperature
6. Soil moisture
7. Soil contamination
8. acidic or basic nature of soil (pH)

Question 6.
How can you say soil is a precious resource? Give reasons.
Answer:

1. Soil is a precious resource.
2. It is the basis for growth of plants.
3. It is habitat for micro organism, animals, reptiles etc.
4. Soil is used for various purposes.
5. Almost all the things in our surroundings directly or indirectly depend on soil.

Question 7.
Why is top soil more useful for us?
Answer:

1. The top organic layer of soil, made up mostly of leaf litter and humus (decomposed organic matter).
2. This layer is soft and porus. It contains nutrients which help in the growth of plants.
3. Top soil is capable of retaining water in it.
4. It is a good habitat for many living organism.

Question 8.
What do farmers do to preserve the fertility of the soil?
Answer:

1. It is very important to preserve the fertility of soil.
2. You know farmers can’t continue the same type of crops in their fields.
3. They know continuous cultivation of same agriculture crops reduce the soil fertility.
4. enerally, farmers cultivate pulses after completion of paddy.
5. This kind of rotation of crops retains soil fertility and productivity.
6. Conservation of soil is important factor in agriculture.

Question 9.
How is the formation of soil happened why are farmers and Engineers testing the soil?
Answer:
Soil Formation:

1. Soil is formed slowly as rock (the parent material) erodes into tiny pieces near the Earth’s surface.
2. Organic matter decays and mixes with inorganic material (rock particles, minerals and water) to form soil.
3. These days farmers test the soil in the field using soil technologies in order to grow suitable crops in the fields.
4. Engineers also test the soil profile before constructing multi storied buildings, bridges and dams.

Question 10.
How can the soil erosion be prevented?
Answer:

1. Our farmers grow big trees around the fields to stop winds.
2. They don’t keep the lands vacant.
3. Farmers generally use vacant lands to grow grass and other plants.
4. These grass plant roots hold the soil particles and prevent soil erosion during heavy rains.

Question 11.
‘Soil is a good habitat’ Explain the statement.
Answer:

1. Soil is a good habitat. We depend on it for agricultural and construction purposes, making utensils, toys etc.
2. We know that plants depend on soil for nutrients like mineral salts and water from the soil
3. Animal life such as burrows or eggs of insects are found in the soil.

Question 12.
Read the below table and answer the following questions.

a) What is the character of loam soil?
b) What is the difference between clay soil and sandy soil?
Answer:
a) When you try to make a cylinder, it can break. This is the light loam soil,

b) Clay Soil : It is very easy to roll into a ball.
Sandy Soil: It is not easy to roll into a ball.

Question 13.
What questions you would ask soil scientist to know the nature of soils?
Answer:

1. Why should we know the nature of soil?
2. Which type of soil is good for growth of the plants?
3. Are the soils same through out the world?
4. If the soil is spoiled, what would happen to plants and animals?

7th Class Science 12th Lesson Soil and Water Long Questions and Answers

Question 1.
How can we conserve the water resources?
Answer:
Conservation of water resources :
Conservation of water can be done using the 4R principle. They include Recharge, Reuse, Revive and Reduce.

Recharge:
The ground water can be recharged by collecting the rain water from the top of the buildings by the process of rainwater harvesting. Percolation tanks, Check dams and Contour trenches cdso help to recharge ground water.

Reuse:
The waste water treated in sewage treatment plants can be used for household activities such as washing vehicles, watering plants and for construction purpose.

Revive:
The practice of reviving the groundwater in drought prone areas is very familiar in olden days. At present the problem of water scarcity can be solved by renovating and reviving the step wells (Digudu Bavulu).

Reduce:
The use and wastage of water can be reduced through different measures. For example we can reduce the wastage of water in agriculture using modern methods of irrigation such as Drip irrigation.

Question 2.
What are the different stages in purification of water?
Answer:

1. Water in rivers, reservoirs and lakes may contain many impurities.
2. Under safe drinking water supply scheme, the water is purified through physical and chemical treatment which includes.
   a) Coagulation : Adding chemicals to bind with impurities in water forming heavy particles.
   b) Sedimentation : Making these heavy particles to settle at the bottom.
   c) Filtration: Passing the upper water through filters to remove remaining undissolved particles.
   d) Disinfection : Adding chlorine or bleaching powder to kill disease causing micro organisms.

Question 3.
What are the different stages involved in sewage water treatment? Explain with the help of a flow chart.
Answer:

1. Water consisting domestic and industrial wastes is treated at sewage or waste water treatment plant.
2. It involves 3 stages. They are
   a) Primary treatment (Physical process)
   b) Secondary treatment (Biological process)
   c) Tertiary treatment (Chemical process)
3. These processes can be explained with the help of the following flow chart.

Question 4.
Fresh water is scarce. What is your contribution to make your family members aware of the need to save water?
Answer:
I shall see that my family members follow the following methods of using water.

1. Pick up water that is required for drinking. Donot throw away the water left out in the glass.
2. Water used for cleaning rice and vegetables will be sent to the garden in the backyard.
3. For bath, required water is to be used
4. I suggest the members to use mild soaps as the water after bath can be sent to plants in the garden of the house.
5. No spill out of water from the tap must be seen by every family member.
6. ‘Think’ before you use every drop of water is the suggestion I put before the family members.

Question 5.
Prepare afleast 5 slogans on “Don’t waste water”.
Answer:
5 slogans on Don’t waste water’.

1. ‘Water is our currency. Use it with care’
2. ‘Water is our life. Save it’.
3. ‘Water is precious. Use it but do not throw it’.
4. ‘Save water. Never become a partner for its shortage’.
5. ‘Water is life. Life is not water’.

Question 6.
How can we conserve water? Write some practices that can be adopted.
Answer:
a) 1) We perform many activities in our daiiy life using water.
2) We can conserve water by adopting certain good practices.

b) Some practices that can be adopted:

1. Water is precious. We should not waste it.
2. Collect water in a bucket after cleaning rice, dal and vegetables in the kitchen which contains peels of vegetables.
3. We can use this water for our cattle.
4. We should not throw solid food remains, tea leaves and oily wastes down the drain.
5. We must make a channel so that the kitchen and bath room water flows to the coconut and banana plants in our garden.
6. We should use only mild soaps and detergents so that this water may not harm our plants.
7. Any leakage of water from any tap must be repaired immediately.

Question 7.
Give reasons for low percolation rate of clayey soil as compared to sandy soil.
Answer:

1. Clayey soil mainly contains clay.
2. Only small percentage of sand and slit are present in the clayey soil.
3. Humus is also present in this soil.
4. The components having good percolation capacity are not present in the clayey soil in the desired proportion.
5. So clayey soil has low percolation rate as compared to sandy soil.

Question 8.
Describe the soil profile.
Answer:
The sequence of horizontal and various components, layers of soil (horizons) at a place is known as Soil profile. Each layer has a distinct colour, texture, depth and chemical composition.These layers are called Horizons.

O Horizon (surface litter) –
is the uppermost, thin horizon, made up of leaf litter and decomposing organic matter.

A Horizon (Top Soil) –
is generally dark consisting dead, decomposed organic matter (humus) mixed with mineral particles. It is soft, porous and retains water hence seeds germinate easily. Plants and many other living organisms get shelter in this fertile layer.

B Horizon (Subsoil) has a lesser amount of humus but consists of clay and more amounts of minerals hence it is harder and more compact. d C

Horizon (Regolith) consists of broken rocks with very little organic matter.

R Horizon (Bedrock) is made up of un weathered rock (bedrock) which is hard and difficult to dig with a spade.

AP Board 7th Class Science 12th Lesson 1 Mark Bits Questions and Answers Soil and Water

I. Multiple Choice Questions

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

1. This is a good habitat for many small organisms.
A) Soil
B) Air
C) Water
D) Fire
Answer:
A) Soil

2. Which of the following soil is used for making utensils and pottery?
A) Shadu soil
B) Multani soil
C) China clay
D) Sandy soil
Answer:
C) China clay

3. Which of the following soil is use in cosmetics?
A) Shadu soil
B) Multani soil
C) Terracotta soil
D) China clay
Answer:
B) Multani soil

4. Which of the following soil is used for making toys and idols?
A) Shadu soil
B) Multani soil
C) Terracotta soil
D) China clay
Answer:
A) Shadu soil

5. The forming process of soil is known as
A) Pedology
B) Weathering
C) Pedogenesis
D) Sedimentation
Answer:
B) Weathering

6. Dead and decayed organic matter that mixes with soil is called …………
A) Soil profile
B) Horizons
C) Humus
D) Particles
Answer:
C) Humus

7. The sequence of horizontal and various components, layers of soil at a place is known as
A) Soil profile
B) Horizons
C) Humus
D) Particles
Answer:
A) Soil profile

8. This type of soil ball can be easily made into a cylinder and a ring.
A) Sandy soil
B) Loamy soil
C) Clayey soil
D) All of the above
Answer:
C) Clayey soil

9. This figure shows
A) Sandy soil
B) Loamy soil
C) Clayey soil
D) All of the above
Answer:
B) Loamy soil

10. Which of the following soil is well aerated and drains quickly?
A) Deltaic alluvial soil
B) Sandy soil
C) Loamy soil
D) Clayey soil
Answer:
B) Sandy soil

11. Deltaic alluvial soil is found in the following districts.
A) Krishna and Nellore
B) East and West Godavari
C) Prakasam and Kurnool
D) Visakhapatnam and Vijayanagaram
Answer:
B) East and West Godavari

12. Black soil is found in the following districts
A) Krishna and Nellore
B) East and West Godavari
C) Prakasam and Kurnool
D) Visakhapatnam and Vijayanagaram
Answer:
A) Krishna and Nellore

13. The percentage of ground and surface water is
A) 1%
B) 2%
C) 3%
D) 97%
Answer:
A) 1%

14. The percentage of fresh water is
A) 1%
B) 2%
C) 3%
D) 97%
Answer:
C) 3%

15. The percentage of marine water is
A) 1%
B) 2%
C) 3%
D) 97%
Answer:
D) 97%

16. The process of entry of water into the ground is
A) Ground water
B) Percolation
C) Infiltration
D) Water table
Answer:
C) Infiltration

17. The absorption and downward movement of water through the soil layers is
A) Ground water
B) Percolation
C) Infiltration
D) Water table
Answer:
B) Percolation

18. The wells, tube wells and hand pumps get water present in the
A) Infiltrations
B) Water tables
C) Aquifers
D) Soil profiles
Answer:
C) Aquifers

19. Adding chemicals to bind with impurities in water, forming heavy particles is
A) Coagulation
B) Sedimentation
C) Filtration
D) Disinfection
Answer:
A) Coagulation

20. Adding chlorine or bleaching powder to kill disease causing micro organisms is
A) Coagulation
B) Sedimentation
C) Filtration
D) Disinfection
Answer:
D) Disinfection

21. Digudu Bavulu is an example for this conservation of water resources.
A) Recharge
B) Reuse
C) Revive
D) Reduce
Answer:
C) Revive

22. Percolation tanks, check dams and contour trenches help to this conservation of water resources
A) Recharge
B) Reuse
C) Revive
D) Reduce
Answer:
C) Revive

23. Drip irrigation is an example for this conservation of water resources.
A) Recharge
B) Reuse
C) Revive
D) Reduce
Answer:
D) Reduce

24. Assertion (A) : Soils can be classified on the basis of proportions of particles of various sizes present in them.
Reason (R) : In loamy soil the proportion of large and fine particles is almost same.
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’.

25. Assertion (A) : Soil is formed by weathering of rocks.
Reason (R) : The process of breaking down of rocks by the action of wind, water, sun and climate is called weathering.
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’ isdalse.
D) ’A’ is false but ‘R’ is true.
Answer:
A) Both A’ and ’R’ are true and ‘R’ is the correct explanation of ‘A’.

26. Statement (i) : Paddy and sugar cane grow very well in sandy soil.
Statement (ii) : Capacity to hold water is much in sandy soil than clayey soil.
Statement (iii) : Clayey soil has poor air circulation.
A) Statement (i) and (iii) are incorrect while (ii) is correct.
B) Statement (i) and (ii) are incorrect while (iii) is correct.
C) All statements are correct.
D) All statements are incorrect.
Answer:
B) Statement (i) and (ii) are incorrect while (iii) is correct.

27. Assertion (A) : Cleaning of water is a process of removing pollutants before it enters a water body.
Reason (R) : The process of cleaning of water and removal of pollutants from it is called “sewage treatment”.
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’.

28. World water day is on
A) 22nd March
B) 20th March
C) 22nd April
D) 20th April
Answer:
A) 22nd March

29. Micro organisms in water cause the disease.
A) Cold
B) Fever
C) Body Pains
D) Cholera
Answer:
D) Cholera

30. Chemical used to disinfect water.
A) Oxygen
B) Chlorine
C) Fluorine
D) Nitrogen
Answer:
B) Chlorine

31. Essential for metabolic activity.
A) CO₂
B) Rain
C) Water
D) Minerals
Answer:
C) Water

32. Chlorine passing into water is called
A) Aeration
B) Chlorination
C) Purification
D) Filteration
Answer:
B) Chlorination

33. Pumping of water into air for purification is called
A) Chlorination
B) Purification
C) Aeration
D) Filteration
Answer:
C) Aeration

34. Which of the following is the top most layer of soil?
A) “O” Horizon
B) “R” Horizon
C) “A” Horizon
D) “B” Horizon
Answer:
A) “O” Horizon

35. Waste water released by different users are collectively called
A) Mud
B) Sewage
C) Sludge
D) None of these
Answer:
B) Sewage

36. Sewage contain
A) suspended impurities
B) dissolved impurities
C) disease causing bacteria
D) all of these
Answer:
D) all of these

37. The process involved in treatment of sewage water
A) physical process
B) chemical process
C) biological process
D) all of these
Answer:
D) all of these

38. Which gas kills harmful disease causing organisms in waste water?
A) Fluorine
B) Chlorine
C) Oxygen
D) Bromine
Answer:
B) Chlorine

39. How much percentage of precipitated water exist in glaciers?
A) 1%
B) 2%
C) 3%
D) 7%
Answer:
B) 2%

40. Sita collects the water that used after cleaning rice, dal and vegetables in the kitchen and uses it to water the garden. This can be called ___
A) Stagnation of water
B) Reuse of water
C) Storing of water
D) Recovering of water
Answer:
B) Reuse of water

41. Soil is a good
A) habitat
B) material
C) source for plant
D) living place for snails
Answer:
A) habitat

42. Soil contains
A) Waste material
B) Humidity
C) Rocks
D) Minerals
Answer:
D) Minerals

43. This soil layer is made up of humus
A) R Horizon
B) A Horizon
C) B Horizon
D) C Horizon
Answer:
B) A Horizon

44. Soil is formed from
A) Rocks
B) Sand
C) Clay
D) Pebbles
Answer:
A) Rocks

45. Percolation rate of water is highest in
A) Rocky soil
B) Black soil
C) Sandy soil
D) Clayey soil
Answer:
C) Sandy soil

46. Percolation rate of water is lowest in
A) Black soil
B) Sandy soil
C) Clayey soil
D) All the above
Answer:
C) Clayey soil

47. Water holding capacity of soil depends on
A) Soil type
B) Rain
C) Place
D) None
Answer:
A) Soil type

48. Below the ‘O’ Horizon and above the ‘B’ Horizon this is found
A) B Horizon
B) A Horizon
C) C Horizon
D) R Horizon
Answer:
B) A Horizon

49. Percolation rate is highest in
A) Sandy soil
B) Clayey
C) Loamy
D) All
Answer:
A) Sandy soil

50. Removal of top soil by wind, water is called
A) soil profile
B) soil fertility
C) percolation
D) soil erosion
Answer:
D) soil erosion

51. Wheat, gram, and paddy are grown In
A) Sandy soil
B) Black soil
C) Clayey and loamy
D) All
Answer:
C) Clayey and loamy

52. This is called regolith
A) R Horizon
B) C Horizon
C) A Horizon
D) O Horizon
Answer:
B) C Horizon

53. This is called sub soil
A) B Horizon
B) C Horizon
C) R Horizon
D) O Horizon
Answer:
A) B Horizon

54. Study of soil is called
A) Morphology
B) Pedology
C) Biology
D) Ecology
Answer:
B) Pedology

55. Cotton is grown in
A) sandy
B) clayey
C) sandy loam
D) heavy loam
Answer:
C) sandy loam

56. The factors responsible for soil erosion
A) wind
B) water
C) deforestation
D) all of these
Answer:
D) all of these

57. It is also called top soil
A) A-horizon
B) B-horizon
C) C-horizon
D) R-horizon
Answer:
A) A-horizon

58. Animals plants and microbes activities are more in this horizon
A) A-horizon
B) R-horizon
C) C-horizon
D) 0-horizon
Answer:
A) A-horizon

59. The right sequence of horizons of the soil from top to bottom is
A) A, B, C, O, R
B) O, A, B, C, R
C) C, A, B, O, R
D) R, C, B, A, O
Answer:
B) O, A, B, C, R

60. Read the statements:
P : Water percolation rate is more to sandy soil.
Q : Water percolation rate is more to loamy soil.
A) Only P is correct
B) Only Q is correct
C) P & Q are correct
D) P & Q are wrong
Answer:
A) Only P is correct

II. Fill in the mlanks

1. The scientific study of soil is called …………….. .
2. The upper most layer of earth’s crust is …………….. .
3. The pleasant smell after the rain is known as …………….. .
4. The substance responsible for petrichor scent is …………….. .
5. Geosmin is produced by …………….. .
6. The breakdown of parent rock into small particles by the action of wind, water, heat and climate is known as …………….. .
7. The process of formation of soil from weathering is known as …………….. .
8. Natural weathering takes a time period of …………….. .
9. Dead and decayed organic matter that mixes with soil is called …………….. .
10. The factors that contribute to soil composition are called …………….. .
11. The science dealing with the influence of soil on organisms, especially on plants is called …………….. .
12. In soil profile, bed rock is present in …………….. horizon.
13. In soil profile, surface litter is present in …………….. horizon
14. …………….. horizon consists of broken rocks with very little organic matter.
15. …………….. soil is less aerated and water held longer.
16. …………….. soil has good aeration, water held but drains slowly.
17. …………….. soil is well aerated and drains quickly.
18. The ratio of the mass of water held in the soil is called …………….. .
19. Paddy is grown in …………….. soil.
20. Cotton is grown in …………….. soil.
21. Cashew is grown in …………….. soil.
22. …………….. is very useful to the farmers to know about the current health of the farm’s soil and how to improve it.
23. Preventing the degradation of soil is known as …………….. .
24. The loss of fertile top soil due to heavy winds and floods is known as …………….. .
25. Water action decade is …………….. .
26. The process of entry of water into the ground is called …………….. .
27. The upper level at which water stands in the ground is called …………….. .
28. The percentage of water present in seas and oceans is …………….. .
29. The percentage of fresh water present on earth is …………….. .
30. The wells, tube wells and hand pumps get water from …………….. .
31. Indiscriminate digging of bore wells leads to …………….. .
32. During purification of water, …………….. chemicals are used for disinfection.
33. Percolation tanks, check dams and contour trenches are helpful in …………….. .
34. Digudu Bavulu are very helpful in …………….. .
35. Best method to prevent soil erosion is …………….. .
Answer:

1. Pedology
2. soil
3. petrichor scent
4. geosmin
5. the spores of Actinomycetes
6. weathering
7. Pedogenesis
8. 500 -1000 years
9. Humus
10. edaphic factors
11. Edaphology
12. R
13. O
14. C
15. Clayey
16. Loamy
17. Sandy
18. moisture content
19. clayey
20. black
21. sandy
22. Soil testing
23. soil conservation
24. Soil erosion
25. 2018-2028
26. infiltration
27. Water table
28. 97%
29. 3% only
30. Aquifer
31. depletion of ground water table
32. chlorine and bleaching powder
33. recharge ground water
34. reviving of ground water
35. planting trees

III. Match the following.

1.

Answer:

2.

Answer:

3.

Answer:

4.

Answer:

5.

Answer:

Do You Know?

→ The pleasant smell ‘after the rain’ is known as petrichor scent. It is due to raising of substance called Geosmin from the soil into the air, when it rains. It is produced by the spores’of by Actinomycetes bacteria.

→ The science dealing with the influence of soil on organisms, especially on plants is called Edaphology. The factors that contribute to soil composition are called edaphic factors.

→ Engineers test the soil profile before constructing multi-storeyed buildings, bridges and dams. They conduct environmental site assessment and make predictions on long term effect of soil on the constructions and give necessary suggestions.

→ Water action decade 2018-2028 :
The UN General Assembly announced that the world will face 40 percent shortfall in fresh water resources by 2030 coupled with a rising world population the world is rushing towards a global water crisis. Recognizing the growing challenge of water scarcity UNO launched the Water Action Decade ( 2018-2028) on 22 March 2018, to mobilize action that will help and transform our vision of management of water.

→ Do you know how modern water purifiers work? Modern Water purifiers that are used to purify water at home have a filter unit and facilities to let Ultra Violet rays to. pass through. Ultra Violet rays are used instead of chlorine treatment to kill the germs.

These AP 7th Class Science Important Questions 10th Lesson Changes Around Us will help students prepare well for the exams.

AP Board 7th Class Science 10th Lesson Important Questions and Answers Changes Around Us

Question 1.
What is a natural change?
Answer:
The change that is brought about by nature itself is called a natural change.

Question 2.
What are man made changes? Give two examples.
Answer:

1. Changes which are taken place by the involvement of human beings are called man made changes.
2. Examples for man made changes are cooking of rice, construction of buildings, preparation of laddu.

Question 3.
What are fast changes? Give examples.
Answer:

1. Changes which occur in short duration of time are called fast changes.
2. Burning of paper, cutting of piece of cake, firing of crackers, spinning of a top are the examples of fast changes.

Question 4.
What are the slow changes? Give examples.
Answer:

1. Changes which take longer duration of time to happen are called slow changes.
2. Examples for slow changes are growing of plant from seed to a tree, developmental changes in the child, rusting of iron, changes of season, formation of mountain etc.

Question 5.
What are reversible changes? Give examples.
Answer:

1. The changes in which the formed substance can be converted into their original substance are called reversible changes.
2. Example for reversible changes are melting of wax, magnetizing a needle using bar magnet etc.

Question 6.
What are irreversible changes? Give examples.
Answer:

1. Changes in which we cannot get the original substance by reversing the experimental conditions are called irreversible changes.
2. Examples are burning of wood, burning of diwali crackers, ripening of fruits, rusting of iron etc.

Question 7.
What are periodic changes? Give examples.
Answer:

1. The changes which are repeating at regular intervals of time are called as periodic changes.
2. Formation of the full moon and new moon, occurrence of seasons in every year at regular intervals, the heart beats of human beings are examples for periodic changes.

Question 8.
What are non-periodic changes? Give examples.
Answer:

1. Changes which do not occur at regular intervals of time and which can not be predicted are called non-periodic changes.
2. Examples are pattern of rainfall, storms in seas, volcanic erruptions etc.

Question 9.
“In a physical change, the chemical properties of a substance do not change.” Do you agree with this statement? How?
Answer:

1. Yes, I agree with this statement.
2. Why because, when a piece of gold is melted, it’s chemical composition remains the same in the solid form and also in the liquid form.

Question 10.
“A physical change is usually temporary and reversible in nature” – Do you agree with this statement? State the reason.
Answer:

1. I absolutely agree with this statement.
2. It is because, when water is heated, water vapours are formed. Once water vapours are cooled water can be obtained again.

Question 11.
“In a physical change, change in physical properties such as colour, shape and size of a substance may under go a change”. Do you support this statement? Why?
Answer:

1. I support this statement.
2. In cutting of vegetables changing physical properties, such as colour, shape and size of a substance.

Question 12.
What is galvanization?
Answer:
The process of deposition of a layer of zinc on iron is called “Galvanization.”

Question 13.
What is a chemical change? Give one example.
Answer:

1. Changes that occur with the formation of new substance with different chemical composition or transformation of a substance into another substance with the evolution or absorption of heat or light energy are called as chemical changes.
2. Example when Magnesium burns in the presence of oxygen, it forms magnesium oxide in the form of powdered ash.
   Magnesium + oxygen → Magnesium oxide

Question 14.
What is rusting?
Answer:

1. When ron reacts with atmospheric oxygen and moisture it forms a new substance called Iron oxide as rust on iron articles made of iron.
2. This process is known as rusting.
   Iron + oxygen (from air) + water → rust (iron oxide)

Question 15.
What are the reasons for global warming?
Answer:

1. Global warming is due to drastic increase in the emission of carbondioxide by the burning of fossil fuels.
2. Deforestation.

Question 16.
What are the reasons for acid rains?
Answer:

1. When coal and oils are burnt, they release acidic gases like NO₂ and SO₂.
2. They mix up with the water vapour and come down as acid rains.

Question 17.
The changes like chicks came out of eggs, blossoming flowers etc. are very pretty to see. List out such changes around you feel happy on observation.
Answer:

1. Swarming of honeybees
2. Rainbow formation
3. Clouds passing across the mountains.
4. Rows of birds flying in the sky.

Question 18.
Give examples for metals that do not rust.
Answer:

1. Metals like gold, silver, zinc do not rust even though they are exposed to moist air.
2. Zinc is used in Galvanization process to prevent rusting of iron articles.

Question 19.
How can you say that rusting is a chemical change?
Answer:

1. When the metals are exposed to air, they form metal oxides.
2. Hence, as new substances are formed, rusting is a chemical change.

Question 20.
Observe the following changes and decode weather they are physical or chemical changes? Mention the reason, a) Preparation of tea b) Making dough for roti.
Answer:
a) This is a chemical change. Water + Milk + Tea powder + Sugar → Tea Here tea is a new substance. Hence it is a chemical change,

b) Making dough for roti is a physical change as there is no formation of new substance.

Question 21.
How is an iron gate prevented from rusting?
Answer:

1. Iron gate when exposed to moisture and air gets rusted.
2. To prevent rusting of Iron gates it should be painted with a paint.

7th Class Science 10th Lesson Changes Around Us Short Questions and Answers

Question 1.
What are the examples for natural changes?
Answer:

1. Formation of day and night
2. Changes of weather.
3. Developmental changes of a child into an adult. ‘
4. rowth of a seed into a plant.

Question 2.
How can we prevent browning of cut fruits and vegetables?
Answer:

1. By keeping the cut vegetables in cold water, we can prevent browning of them.
2. Cold water prevents the outer surface of the potato and brinjal from colouring.
3. Small quantities of acids like vinegar or lemon juice in water will also prevent browning of vegetables.
4. We can also rub the surface of cut fruits with juices of citrus fruits like lemon to avoid from browning.
5. Ascorbic acid can also be used to prevent browning.

Question 3.
What is the reason for browning of vegetables in our daily life?
Answer:

1. Some fruits and vegetables like potato and brinjal, when they cut react with oxygen in air.
2. The process of reaction with oxygen is called oxidation.
3. Due to this oxidation process, brown layer is formed on the surface of fruits and vegetables.

Question 4.
What are the harmful physical and chemical changes in environment?
Answer:

1. Plastic decomposition
2. Acid rains
3. Global warming
4. Oil spills in seas and rivers
5. Earthquakes and
6. Floods are some of the harmful physical and chemical changes in environment.

Question 5.
What changes might have we noticed in our daily life?
Answer:

1. The colour ,of tender leaf changing from red to green.
2. Hard raw fruit becoming soft ripen fruit.
3. Colour changes observed in slices of brinjal and apple after being cut.
4. Change of milk into the curd.
5. Ash produced on burning paper.
6. Raw rice becoming soft after cooking etc.

Question 6.
What questions would you pose to your teacher about changes around us?
Answer:

1. Why changes occur around us?
2. Why would we depend on changes in the nature?
3. What would happen if changes do not occur?
4. How changes in the nature influence us?

Question 7.

What type of change is it? Is itreversible? If so, how?
Answer:

1. Ice slowly melts and becomes water.
2. On further heating water changes to steam.
3. This is a physical change.
4. No new substance is formed.
5. The change is reversible. If we reduce the temperature the water vapour changes back to water when the temperature is further reduced, it changes to ice.
   

Question 8.
What are the characteristics of a physical change?
Answer:

1. No new substances are formed.
2. It is usually temporary and reversible in nature.
3. The chemical properties of a substance do not change.
4. Change in physical properties such as colour, shape and size of a substance may undergo a change.

Question 9.
What are the characteristics of a chemical change?
Answer:

1. During chemical change new substance are formed.
2. It is a permanent change and irreversible in nature.
3. Chemical composition of the substances changes.
4. Heat, light may be released or absorbed.
5. A colour change may take place and sound may be produced.

Question 10.
Where do you see the iron pilar that is not rusted for thousands of years? What are the reasons for that?
Answer:

1. We can see an iron pillar at the Qutub complex in Delhi which is not rusted. It is 1600 years old.
2. It is made by 98% wrought iron, a special type of iron that has 1% of phosphorous.
3. It don’t have Sulphur and Magnesium.
4. More over, the pillar is covered by a thin layer of compound called Misawitea.
5. So, rusting of this iron pillar is too slow and it will take thousands of years to get rusted.

Question 11.
What is so special about Lonar Lake?
Answer:

1. The Lonar lake in Buldhana district of Maharashtra was created by plummeting meteor about 5200 years ago.
   
2. The water of Lonar lake turned into pink colour recently due to Haloarchaea microbes present in the salty water.
3. But the colour is not permanent.
4. When the biomass of the microbes settled at the bottom, then the water again becomes transparent.

Questions 12.
Anurag appreciates the changes in ripe mango as “How nice its colour and taste are”? Give some examples of changes that makes you feel happy, or wonder.
Appreciate them in your own words.
Answer:

1. When mango ripens, the contents present in the fruit gives good taste. The change in colour indicates that the fruit is ripend.
2. Similar situations we experience with many fruits like banana, guava, papaya, pine apple … etc.
3. In fact fruits are a gift to human beings as they give instantaneous energy when eaten.
4. Nature is so kind to us to provide such ready made safe foods.

7th Class Science 10th Lesson Changes Around Us Long Questions and Answers

Question 1.
What is rust and rusting? Why does iron rust? What type of a change is this?
Answer:

1. When iron nails, iron gates, iron benches or pieces of iron are left is the open ground for a long time, we find a brown layer on the surface of iron articles.
2. This is called rust’ and process of forming this layer is called rusting.
3. When iron is exposed to air for a long time, the Oxygen present in air reacts with it in the presence of moist air and forms a new substance called iron oxide as rust on iron articles. This process is known as rusting.
   Iron + Oxygen (from air) + Water → rust (Iron oxide)
4. As a new substance is formed in this change, we call it a chemical change.

Question 2.
Answer the following questions.
The gas we use in kitchen is in the form of liquid in the cylinder. When it comes out from the cylinder it becomes a gas (step-I), then it burns (step-II).
Choose the correct statement from the following.
a. Only step – I is a chemical change.
b. Only step – II is a chemical change.
c. Both steps – I & II are chemical changes.
d. Both steps – I & II are physical changes.
Answer:
a) Step -1 – is a physical change (not a chemical change)
b) Step – II – is a chemical change (It is correct)

c) Both steps I & II – are chemical changes.
This is not correct.
Step – I – Physical change and
Step – II – Chemical Change is correct.

d) Both steps I & II – are physical changes – This is not correct.
Step I – Physical change
Step II – Chemical change.

Question 3.
What are periodic changes? Explain briefly.
Answer:

1.  If we observe that every change mentioned is the table repeats after some period of time.
2. Such changes are known as periodic changes.
3. The events which repeat at regular intervals of time are called periodic events.

Question 4.
What is Galvanisation? Explain its importance.
Answer:

1. Some articles made up of iron, don’t get rusted even they are exposed to air.
2. To prevent iron articles from coming into contact with oxygen in air or water or both, we deposit a layer of a metal like Chromium or Zinc on them.
3. This process of depositing a layer of zinc or Chromium on Iron is called Galvanisation.
4. Generally we use Zinc for such type of coatings.
5. We find in our house that water pipe lines are without rust on them.
6. If we observe carefully, we notice that there is some metallic coating on these pipes to prevent rusting.
7. They do not get rusted even after a long time since they are galvanized.
8. The process of depositing one metal on another metal is called galvanisation.

Question 5.
Write the environmental issues due to physical and chemical changes.
Answer:
Physical and chemical changes occur all around us. These changes are essential parts of our daily lives. However a few of the physical and chemical changes that occur daily are harmful to the environment.

For example

1. Plastic decomposition, global warming, effects of acid rain and oil spills, earthquakes, floods etc.
2. Plastic waste is a widely recognised source of pollution. Most plastics are non- biodegradable. They take hundreds of years to decompose. Hence their disposal causes pollution.
3. Global warming is due to drastic increase in the emission of carbon dioxide by the burning of fossil fuels. The climate change affects not only the atmosphere and living things on land but also creatures of ocean.
4. Acidic gases are produced when fossil fuels such as coal and oil are burned in power station, factories and homes.
5. Oil spills occur when liquid petroleum is released into the environment by human interference causing damage to creatures of ocean.
6. Changes are quite common in nature. Human beings are misusing the natural re-sources for their needs.
7. But we should take care that our needs should not bring drastic changes that causes harm to the nature and mankind.

AP Board 7th Class Science 10th Lesson 1 Mark Bits Questions and Answers Changes Around Us

I. Multiple Choice Questions

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

1. Change in the shape of balloon is done by bibwing air into it. This is a……
A) manmade change
B) natural change
C) chemical change
D) periodic change.
Answer:
A) manmade change

2. Which of the following is not a man made-change?
A) preparation of bricks
B) making of paper
C) weaving of clothes
D) growing of nails
Answer:
D) growing of nails

3. Which of the following is not a fast change?
A) burning of paper
B) firing of crackers
C) making of a cake
D) spinning of a top
Answer:
C) making of a cake

4. The change happens in less time is.
A) slow change
B) fast change
C) periodic change
D) non periodic change.
Answer:
B) fast change

5. Which of the following is not reversible?
A) Weight suspended from a spring
B) Water changed to water vapour
C) Inflating of a balloon
D) Burning of a coal
Answer:
D) Burning of a coal

6. On …………… ice converts to water
A) heating
B) cooling
C) freezing
D) evaporating
Answer:
A) heating

7. some changes we cannot regain the original substance, these are.
A) manmade change
B) natural change
C) irreversible change
D) reversible change
Answer:
C) irreversible change

8. Limewater
A) Calcium Hydroxide
B) Sodium hydroxide
C) Potassium hydroxide
D) Carbonic acid
Answer:
A) Calcium Hydroxide

9. Which of the following is an irreversible change?
A) burning of wood
B) burning of Diwali crackers
C) ripening of fruits
D) all
Answer:
D) all

10. Which gas is released when lemon juice reacts with baking soda?
A) oxygen
B) carbon dioxide
C) nitrogen
D)water vapour
Answer:
B) carbon dioxide

11. These changes are repeating at regular intervals of time.
A) slow change
B) fast change
C) periodic change
D) non periodic change.
Answer:
C) periodic change

12. Changes which do not occur at regular intervals of time and which cannot be predicted are called
A) slow change
B) fast change
C) periodic change
D) non periodic change
Answer:
D) non periodic change

13. Crystallization requires
A) heating
B) cooling
C) evaporating
D) A or C
Answer:
A) heating

14. In crystallization….
A) no new substances are formed.
B) new substances are formed.
C) no heating is required
D) none
Answer:
A) no new substances are formed.

15. Crystallization is
A) chemical change
B) physical change
C) periodic change
D) non periodic change
Answer:
B) physical change

16. Choose correct answer.
S: Crystallization is a Physical Change.
R: In crystallization no new substances are formed.
A) S and R are correct.
B) S and R are incorrect.
C) S is correct and R is incorrect.
D) S is incorrect and R is correct.
Answer:
A) S and R are correct.

17. Which change takes place when ice cube melts?
A) colour
B) phase
C) chemical
D) all
Answer:
B) phase

18. When a piece of gold is melted?
A) no new substances are formed.
B) new substances are formed.
C) chemical composition changes
D) none
Answer:
A) no new substances are formed.

19. When a piece of gold is melted, its chemical composition in the Solid form and also in the liquid form.
A) changes
B) varies
C) remains same
D) different
Answer:
C) remains same

20. In physical change ……….. changes.
A) shape
B) colour
C) size
D) all
Answer:
D) all

21. It is not a characteristic of a physical change…
A) No new substances are formed
B) Temporary and reversible in nature.
C) The chemical properties of a substance do not change.
D) It is a periodic change.
Answer:
D) It is a periodic change.

22. In curdling of milk is
A) a physical change
B) reversible change
C) chemical change
D) temporary change
Answer:
C) chemical change

23. When magnesium burns in the presence of oxygen, it forms magnesium oxide
A) magnesium oxide
B) magnesium chloride
C) carbon dioxide
D) none
Answer:
A) magnesium oxide

24. Magnesium Hydroxide is…..
A) an acid
B) a base
C) a neutral
D) none
Answer:
B) a base

25. Characteristic of a chemical change
A) During chemical change new substances are formed.
B) It is a permanent change and irreversible in nature.
C) Chemical composition of the substance changes.
D) All
Answer:
D) All

26. In chemical change which is not happens.
A) Heat, light may be released or absorbed.
B) A colour change may take place and sound may be produced.
C) Original substances may be formed on reversing the process
D) None
Answer:
C) Original substances may be formed on reversing the process

27. Rusting of iron requires
A) moisture
B) air
C) both
D) none
Answer:
C) both

28. Rust is…
A) iron oxide
B) calcium chloride
C) iron peroxide
D) above all
Answer:
A) iron oxide

29. Oxidization is observed in
A) iron articles
B) apples
C) brinjal
D) none
Answer:
D) none

30. Which of the following is used to prevent browning of the outer surface of the potato and brinjal?
A) cold water
B) lemon juice
C) ascorbic acid
D) above all
Answer:
D) above all

31. Which of the following is used in galvanizing?
A) zinc
B) chromium
C) A & C
D) none
Answer:
C) A & C

32. This process of deposition of a layer of zinc on iron is called
A) oxidation
B) galvanization
C) crystallization
D) none
Answer:
B) galvanization

33. Due to this process of brown layer is formed on the surface of fruits and vegetables.
A) oxidation
B) galvanization
C) crystallization
D) none
Answer:
A) oxidation

34. Which of the following is a useful change?
A) global warming
B) acid rain
C) plastic decomposition
D) fermentation
Answer:
D) fermentation

35. Which of the following occurs due to drastic increase in the emission of carbon dioxide by the burning of fossil fuels
A) global warming
B) floods
C) earth quakes
D) fermentation
Answer:
A) global warming

36. Ice converting to water, water converting to steam are ………. changes.
A) reversible
B) chemical
C) periodic
D) all
Answer:
A) reversible

37. Ripening of fruits is ………….. change.
A) reversible
B) physical
C) periodic
D) irreversible
Answer:
D) irreversible

38. The change occurs only in Size, colour and shape of the substance and no change in chemical composition are called ………….. changes
A) chemical
B) physical
C) periodic
D) irreversible
Answer:
B) physical

39. ………. change occurs with the formation of new substance in different chemical composition.
A) Reversible
B) Physical
C) Periodic
D) Chemical
Answer:
D) Chemical

40. The process of depositihg zinc on iron metals is called
A) oxidation
B) galvanization
C) rusting
D) crystallization
Answer:
B) galvanization

II. Fill in the blanks.

1. The changes which were taken place by the involvement of human beings are called ………………. change.
2. Changes which occur in ………………. duration of time are called fast changes.
3. Changes which takes longer duration of time to happen are called ………………. Change.
4. Changing of vegetable to curry : slow reaction:: changing of acid into vapour ………………. .
5. On ………………. water converts to ice.
6. The changes in which the formed substance can be converted into their ………………. are called reversible changes.
7. ………………. changes Limewater into milky white.
8. Vinegar + Baking Soda → Sodium acetate + ………………. + water
9. ………………. + Lime water → Calcium carbonate + water
10. Changes in which we cannot get the original substance by reversing the experimental conditions are called ………………. Changes.
11. ………………. changes are repeating at regular intervals of time .
12. The process of separating a soluble solid from the solution by heating or evaporating is called ………………. .
13. A ………………. is usually temporary and reversible in nature.
14. The substances which undergo change in colour or state or size or shape are ………………. .
15. When a Magnesium ribbon burns it gives ………………. light leaving a powdery substance behind.
16. ………………. + Water → Magnesium Hydroxide
17. Changes that occur with the formation of new substance with different chemical composition or transformation of a substance into another substance with the evolution or absorption of heat or light energy are termed as ………………. .
18. Iron + Oxygen (from air) + Water → ……………….
19. Apply a coat of paint or grease on iron articles. Prevents ………………. .
20. To prevent iron articles from coming contact with oxygen in air and water, a layer of another metal like ………………. is coated on them.
21. The process of deposition of a layer of zinc on iron is called ………………. .
22. Browning is not only observed on iron articles but also on cut fruits and ………………. .
23. Rubbing of the surface of cut fruits with ………………. to avoid from browning.
24. The process of reaction with ………………. is called oxidation.
25. ………………. waste is a widely recognized source of pollution.
26. ………………. gases are produced when fossil fuels such as coal and oil are burned in power station, factories and homes.
27. Oil spills occur when ………………. is released into the environment.
28. Formation of day and night, occurrence of seasons are ………………. changes.
29. Curding of milk : useful changes :: ………………. : harmful change.
Answer:

1. 1. man-made
2. short
3. slow
4. fast reaction
5. cooling
6. original substance
7. Carbon dioxide
8. carbon dioxide
9. Carbon dioxide
10. irreversible
11. periodic changes
12. crystallization
13. physical change
14. physical changes
15. brilliant white dazzling
16. Magnesium Oxide
17. chemical change
18. rust (Iron oxide)
19. rusting of iron
20. chromium or zinc
21. Galvanization
22. vegetables
23. juices of citrus fruits
24. oxygen
25. Plastic
26. Acidic
27. liquid petroleum
28. periodic
29. global warming

III. Match the following.

1.

Answer:

2.

Answer:

3.

Answer:

4.

Answer:

5.

Answer:

Do You Know?

→ Belum caves are naturally formed caves located near Kolimigundla mandal of Kurnool district. These are the second largest caves in Indian subcontinent after Meghalaya state caves. The name is derived from Bilum” Sanskrit word for caves. The caves reach its deepest point (120 feet from entrance level) at the point known as “Paathalaganga” only 1.5 km is open to tourists. In 1988 Andhra Pradesh Tourism , Development Corporation (APTDC) declared them protected and developed the caves as a tourist attraction in February 2002. Borra Caves are also famous natural caves located at Visakhapatnam District.

→ The Lonar lake in Buldhana district of Maharashtra was created by plummeting meteor about 5200 years ago. The water of Lonar lake turned into pink colour recently due to Haloarchaea microbes present in the salty water. But the colour is not permanent. When the biomass of the microbes settled at the bottom, then the water again becomes transparent.

→ The Iron pillar at Delhi :
Amazingly there is an iron that did not rust! There is an iron pillar at the Qutub complex in Delhi which is more than 1600 years old. Even after such a long period, the iron pillar kept in open space has hot rusted at all. Do you know how? It is made by wrought iron which contains more amounts of phosphorus than usual. The main reason for rust resistance is due to the formation of Iron hydrogen phosphate on its surface. So its takes more time to rest. That’s why still the iron pillar at Delhi did not get rust.

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:

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:

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.

Answer:

Question 40.
Fill in the table with suitable answers.

Answer:

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:

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.

Answer:

2.

Answer:

3.

Answer:

4.

Answer:

5.

Answer:

6.

Answer:

7.

Answer:

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.