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AP State Syllabus AP Board 8th Class Physical Science Important Questions Chapter 5 Metals and Non-Metals

AP State Syllabus 8th Class Physical Science Important Questions 5th Lesson Metals and Non-Metals

8th Class Physical Science 5th Lesson Metals and Non-Metals 1 Mark Important Questions and Answers

Question 1.
What is meant by lustrous material?
Answer:
The material which show brightness on surface and reflect the light are called lustrous material.

Question 2.
What is malleability? Which materials have malleability?
Answer:
The property of material by which they can beaten into thin sheets is called malleability. Generally metals exhibit malleability property, e.g.: Iron, copper, etc.

Question 3.
What is ductility? Which materials show ductility?
Answer:
The property of drawing materials to make fine wires is called ductility. Generally metals show ductility, e.g.: Gold, copper, etc.

Question 4.
Have you observed materials used to make school bell or bells in temple ?
Answer:
Generally they are made up of metals.

Question 5.
Why do wooden bells not used in temple?
Answer:
Wood does not give a ringing sound when it is hit with a hammer. That means it does not show sonorous property. So wooden bells are not used in temple.

Question 6.
What is meant by sonorous?
Answer:
The ability to material to produce a particular sound when it is dropped on the hard surface is called sonorous.

Question 7.
Is ductility is the only property to use them as connecting wires in electric circuits?
Answer:
No, it is one of the cause. The other thing is metals are very good conductors of electricity. So they easily allows the passage of current. So they are used as connecting wires.

Question 8.
What does cooking appliances conduct?
Answer:
Cooking appliances conduct heat from heating device like gas stove or electric stove.

Question 9.
What is the nature of metallic and non-metallic oxides?
Answer:
Generally metallic oxides are basic in nature and non-metallic oxides are acidic in nature.

Question 10.
What happen when keep an iron rod in open place for one or two days?
Answer:
Rusting takes place on iron. The reason is iron react with air that contains oxygen and moisture forms a reddish brown coating (rust) due to formation of iron oxide.

Question 11.
Why do some metals do not get rust?
Answer:
Metal with very low reactivity do not react with air. So they do not get rust. They also called as noble metals, e.g.: Gold, platinum.

Question 12.
What happens when magnesium ribbon is exposed to air?
Answer:
It becomes dull when it is exposed to air due to formation of magnesium carbonate. That’s why magnesium ribbon should be cleaned with sand paper before any chemical reaction.

Question 13.
Why does silver objects and jewellery become black after sometime?
Answer:
Silver articles are black after sometime because they react with oxygen in air and form silver oxide.

Question 14.
Why statues and vessels made up of copper become dull green after certain time?
Answer:
The statues and vessels made up of copper became dull because they react with air and form copper hydroxide and copper carbonate which appears as dull green coating.

Question 15.
What happens when non-metals are added to water?
Answer:
They do not react with water.

Question 16.
How do you test hydrogen gas?
Answer:
If we place a burning match stick near a test tube containing hydrogen gas it puts out the match stick with pop sound and the gas burns with blue flame.

Question 17.
What happens when acids are added to non-metals?
Answer:
Non-metals do not react with acids.

Question 18.
What is a displacement reaction?
Answer: A more reactive metal displace a less reactive metal from its compound in aqueous solution is called displacement reaction.

Question 19.
Which metal has highest ductility?
Answer:
Gold. One gram of gold can be drawn into a wire of length one kilometre.

Question 20.
Why sodium and potassium are stored in kerosene?
Answer:
Sodium and potassium are highly reactive. They react vigorously with oxygen and water. A lot of heat is generated in the reaction. Therefore these metals are stored in kerosene.

Question 21.
Is all metals are hard?
Answer:
No. Sodium and potassium are soft. So they can be cut with a knife.

Question 22.
Which non-metal has lustrous surface?
Answer:
Iodine has lustrous surface.

Question 23.
Which non-metal is extremely hard?
Answer:
Diamond (allotrope of carbon) is extremely hard.

Question 24.
Why immersion rods for heating liquids are made up of metallic substances?
Answer:
Metals are good conductors of heat. So immersion rods for heating liquids are made
up of metals.

Question 25.
Why does copper cannot displace zinc from its salt solution?
Answer:
Copper is less reactive than zinc. So it cannot displace zinc from its salt solution.

Question 26.
Why does aluminium foils are used to wrap food items?
Answer:
It does not readily react with food items. So aluminium foils are used for wraping food items.

Question 27.
The doctor reported iron deficiency in my body. Where is iron in my body?
Answer:
Iron is present in haemoglobin. Which gives red colour to blood.

Question 28.
I heard that magnesium is found in plants. In what form is it found in them?
Answer:
Magnesium is present in chlorophill. It is in Mg(II) state.

Question 29.
Gold jewellery does not become dull. Why?
Answer:
Gold and platinum does not react with components of air. So, gold and platinum does not rust. So gold jewellery does not become dull.

8th Class Physical Science 5th Lesson Metals and Non-Metals 2 Marks Important Questions and Answers

Question 1.
What are physical properties of non-metals?
Answer:
Physical properties of non-metals:

1. They are non lustrous.
2. They are non sonorous.
3. They are soft.
4. They does not show malleability and ductility.
5. They are bad conductors of heat and electricity.

Question 2.
Is our body is a metal or a non-metal?
Answer:
Most of the human body is made of water (H₂O). It is not surprising that majority of a human body’s mass is oxygen. Carbon, the basic unit of organic molecules is the second. 99% of human body is made up of just six elements. Oxygen (65%), carbon (18%), hydrogen (10%), nitrogen (3%), calcium (1.5%), phosphorous (1%). Which shows our body has almost 97% of non-metals. So we may consider our body as non-metal.

Question 3.
Draw a diagram which shows metals are good conductors of electricity.
Answer:

Question 4.
Draw a diagram which show metals are good conductors of heat.
Answer:

Question 5.
Explain about ductility.
Answer:

1. Some materials cannot be drawn into wires.
2. Property of drawing a material to make fine wires is called ductility.
3. Most metals are ductile.

Question 6.
How do you appreciate the efforts of man to use the Metals in making tools?
Answer:

1. Early human beings made their tools from stone and wood.
2. Later they used the bones of animals.
3. Then they discovered metals like copper and iron.
4. Tools made of copper and iron are much stronger than tools made of stone and wood.
5. Metals had the advantage of not just being harder but they can be heated in a fire and moulder or cast into different shapes. So it became possible to make a wider range of tools with such metals.
6. Hence the efforts of man to use the metals in making tools appreciated.

Question 7.
You came to know that the Diamond is a hardest material and it is a non-metal and similarly Mercury is a soft material and it is a metal.Write down the questions raised in your mind.
Answer:

1. Are all metals hard?
2. Are there any non-metals hard like diamond?
3. Are there any metals soft like mercury?
4. What makes mercury so soft and diamond so hard?
5. Can we distinguish those metals and non-metals depending on their opposite properties like these examples?

Question 8.
Taking the example of magnesium and sulphur explain how metals and non-metals produce with different characteristics.
Answer:

1. Magnesium in the presence of oxygen burns to produce basic magnesium oxide. When it its added to water, it produces magnesium hydroxide, which turns the red litmus solution into blue.
2. Sulphur combines with oxygen, it forms acidic oxide. It get changed into sulphurous acid when react with water. This turns the blue litmus solutions into red.

Question 9.
What happens when
a) Dilute sulphuric acid is poured on a copper plate?
b) Iron nails are placed in copper sulphate solution?
Answer:
a) Copper sulphate is formed and hydrogen gas is released.
copper + dilute sulphuric acid → copper sulphate + hydrogen gas
b) Brown coating is deposited on the Iron nails. This is because of displacement of copper from copper sulphate solution by Iron.
Iron + Copper sulphate_(solution) → Iron sulphate_(solution) + Copper

8th Class Physical Science 5th Lesson Metals and Non-Metals 4 Marks Important Questions and Answers

Question 1.
What happens when magnesium, sulphur burnt in the presence of oxygen ? Write the word equation.
Answer:
When magnesium is burnt in the presence of oxygen it burns brilliantly and forms white ashes of magnesium oxide.

When sulphur is burnt in the presence of oxygen, it forms a yellowish gas called sulphur dioxide.

Question 2.
What are uses of various non-metals?
Answer:
Uses of non-metals:

1. Oxygen is essential for all living beings.
2. Nitrogen as fertilizer enhance the growth of plants.
3. Chlorine is used to purify the water.
4. Sulphur is used in making fire works, crackers, gun powder, match sticks and anticeptic ointments.
5. Activated carbon is used as decolourising agent and also in water purification systems.
6. Tincture iodine is used in medical purpose.

Question 3.
What are the uses of metals?
Answer:
Uses of metals:

1. Gold, silver, copper are used in making jewellery.
2. Silver foil is used in decoration of sweets.
3. Aluminium foil is used in inner packing of food materials and toffees.
4. Aluminium and copper mixture is used in currency coins, medals and statues.
5. Zinc and iron mixture is used in making of iron sheet.
6. Most of agricultural instruments are made by iron.
7. Electrical appliances, automobiles, satellites, aeroplanes, cooking utensils, machinery decorative materials are made by metals.

Question 4.
Prepare a table of various metals and non-metals used in our daily life and their usage.
Answer:

Metals/non-metals	Their usage
1) Gold	Jewellery
2) Silver	Jewellery
3) Copper	Jewellery, utensils, electrical appliances
4) Aluminium	Utensils, packing of food, aeroplanes, satellites
5) Iron	Utensils, electric appliances, agricultural tools
6) Iodine	Medical purpose
7) Chlorine	Purification of water
8) Nitrogen	Fertilizers
9) Sulphur	Gun powder, matchsticks, fire works, crackers, antiseptic ointments
10) Oxygen	Essential for all living things to live

Question 5.
The nature of oxides helps to identify the metals and non-metals conduct an experi-ment to prove this and record the observations.
Answer:
I) Aim: The nature of oxides helps to identify the metals.
Material required : Magnesium sample, spirit lamp, red litmus paper.
Procedure:

1. Take a small strip of magnesium and burn it and note the appearance after the reaction.
   Reaction: When we burn the sample of magnesium, it reacts with oxygen in air and form magnesium oxide.
   
2. Take magnesium oxide solution and place red litmus in it. Red litmus turns to blue indicates the solution is basic in nature.

Result: Metallic oxides solutions are basic in nature. So if the oxide solution is basic then the oxide is formed by a metal.

II) Aim: The nature of oxides help to identify the non-metals.
Material required: Sulphur sample, spirit lamp, blue litmus paper, deflagrating spoon. Procedure:

1. Take a small amount of sulphur powder in a deflagrating spoon and heat it.
2. As soon as sulphur starts burning, introduce the spoon into glass jar or tumbler.
3. Add small quantity of water into the tumbler and quickly replace the lid. Shake the tumbler well.
   Reaction: Sulphur burns and reacts with oxygen in air to give sulphur dioxide.
   
4. Place blue litmus paper in the prepared solution it turns to red indicates the solution is acidic nature.

Result: Non-metallic oxides solution are acidic in nature. So if oxide solution turns blue litmus into red then the oxide is formed by a non-metal.

Question 6.
Collect the information about metals which we Use in our daily life, and their uses. Write a report on it.
Answer:

1. The special properties of metals help us in many ways.
2. Metals are lustrous (shining). So, we make ornaments of gold and silver.
3. Metals are sonorous. So, we make school bells, temple bells, gongs, etc.
4. The malleability of metals help us to make sheets of iron, etc.
5. Ductility is the special character of metals which help us in making wires.
6. Metals conduct heat and electricity. Hence we make utensils for cooking and electrical wires etc.
7. Metals react with oxygen and produce oxides of basic nature.
8. Metals react with acids (dilute) and liberate hydrogen gas. So, in the preparation of hydrogen gas, metals come in use.
9. Non-metal like sulphur is used in making fire works, crackers, gun powder, matchsticks and antiseptic ointments.

Question 7.
Give reasons for the following.
a) Aluminium foils are used to wrap food items.
b) Immersion rods for heating liquids are made up of metallic substances.
c) Copper cannot displace Iron from its salt solution.
d) Sodium and potassium are stored in Kerosene.
Answer:
a) Aluminium has high malleability. So it is very easy to make aluminium foil compared other metals.
b) Because metals are good conductors of electricity.
c) Iron has more reactivity than copper. So copper cannot displace Iron from its salt solution.
d) Sodium and potassium have high reactivity with water and an even they burn in the presence of air and water. So these metals are stored in Kerosene.

Question 8.
Give reasons for the following.
i) Silver is used in making mirrors.
ii) Aluminium is used to make electrical wires.
iii) Sour food substances should not be stored in aluminium utensils.
iv) Iron is used in constructing bridges and houses.
Answer:
i) Silver has high reflecting power.
ii) Aluminimum is good conductor of electricity.
iii) Sour substances contain acids which react with aluminimum utensils to form toxic substances.
iv) Iron is hard, strong and rigid material.

Question 9.
Give some differences with examples between metals and non-metals with reference to their properties. Give one exception in each case.
Answer:
a) Lustrous: Metals have shining surfaces. So they are called Lustrous. Whereas non-metals have dull surface so they are non Lustrous.
One of the form of carbon is diamond has most shining look.
Iodine a non-metal also has lustrous surface.
b) Malleability: Metals can be beaten into sheets and non-metals cannot be beaten into sheets. But mercury is a metal which breaks into pieces when hammered.
c) Ductility: Metals are drawn into wires. Non-metals cannot be drawn into wires. Mercury does not show ductility.
d) Conductivity: Metals are good conductors of heat and electricity and non-metals are bad conductors of electricity and heat. Graphite is a non-metal which is good conductor of heat and electricity.
e) Hardness: Metals are usually hard and non-metals are soft. But sodium and potassium are quite soft, they can be cut by using a knife. Diamond is a non-metal which is the hardest substance.

8th Class Physical Science 5th Lesson Metals and Non-Metals Important Questions and Answers

Question 1.
Predict the reason behind gold and platinum jewellery does not become dull.
Answer:
Gold and platinum does not react with components of air. So, gold and platinum does not rust. So gold jewellery does not become dull.

Question 2.
Write any two differences between electric conductors and insulators.
Answer:

Electric conductors	Electric insulators
1) Those substances through which electricity can flow are called conductors.	1) Those substances through which electricity cannot flow are called insulators.
2) Generally metals are conductors. Eg: Silver, copper	2) Generally non-metals are insulators. Eg: Rubber, plastic, glass

Question 3.
Write any four uses of metals in different situations.
Answer:
Uses of metals:

1. Gold, silver, copper are used in making jewellery.
2. Silver foil is used in decoration of sweets.
3. Aluminium foil is used in inner packing of food materials and toffees.
4. Aluminium and copper mixture is used in currency coins, medals and statues.
5. Zinc and iron mixture is used in making of iron sheet.
6. Most of agricultural instruments are made by iron.
7. Electrical appliances, automobiles, satellites, aeroplanes, cooking utensils, machinery decorative materials are made by metals.

Question 4.
Explain the reaction of metals with acids.
Answer:
Aim: To find the reactivity of metals with acids.
Apparatus: Test tube, dilute hydrochloric acid, magnesium ribbon, spirit lamp. Procedure:

1. Take a magnesium ribbon and rub with a sand paper.
2. Put this ribbon into a test tube containing dilute hydrochloric acid.
3. A gas is evolved from the test tube.
4. Now bring a burning match stick near the mouth of the test tube.
5. The gas puts off the match stick and produces a pop sound and gas burns with blue flame.
6. Which indicates hydrogen gas is released.
7. We will get same results with zinc, iron, copper also.
8. Conclusion: Metal reacts with acid and produce hydrogen gas.

Question 5.
Explain a procedure to do the experiment that magnesium ribbon allows the flow of current.
Answer:
Procedure:

1. Arrange ah electric circuit with a battery and bulb.
2. Close the circuit using a magnesium ribbon.
3. Observe whether the bulb is glow or not.

Observation: Bulb glows.
Conclusion: Magnesium ribbon allows the flow of current.

Question 6.
Suggest an activity to show that the magnesium ribbon reacts with Oxygen to form Magnesium Oxide, which is basic in nature.
Answer:
Aim: To know reaction of oxygen with metals.
Material required: Magnesium strip, spirit lamp or Bunsen burner and litmus papers, distilled water.
Procedure:

1. Take a small strip of magnesium.
2. Burn it with spirit lamp.
3. It burns brilliantly and produce white ashes of magnesium oxide due to reaction between magnesium and oxygen.
4. Collect the ash of magnesium in a watch glass and add some distilled water.
5. Test the solution with red litmus paper and blue litmus paper.

Observation: Red litmus paper turns into blue in colour.
Conclusion: Metallic oxide solutions are basic in nature.

Question 7.
Zinc, Copper, Sulphur, Carbon, Categories into these into metals and non-metals and write their uses.

S.No.	Name	Metal/Non-metal	Use
1. 2. 3. 4.

Answer:

S.No.	Name	Metal/Non-metal	Use
1.	Zinc	metal	sheets, batteries
2.	Copper	metal	electrical wires, jewellary, Utensils
3.	Sulphur	non-metal	Gun powder, fireworks, ointments
4.	Carbon	non-metal	Water purifiers, fuel

Question 8.
You are given copper sulphate, Iron sulphate, an iron nail and copper wire. How do you test the reactivity of metals iron and copper Explain through an activity.
Answer:
Activity:

1. Take two beakers ‘a’ and ‘b’.
2. Take 50 ml of water in each.
   
3. Dissolve some amount of copper sulphate in beaker ‘a’ and iron sulphate in beaker ‘b’.
4. Drop iron nails in beaker ‘a’ and copper wire in beaker ‘b’.
5. Leave the beakers for some hours.

Observations:
i) In beaker ‘a’ copper layer forms on the iron nails and blue colour of copper sulphate turns pale blue or white.
ii) No change in beaker ‘b’.
Conclusion:
i) Copper is displaced by iron in beaker ‘a’.
Copper Sulphate + Iron → Iron sulphate + Copper
ii) Iron is not displaced by copper in beaker ‘b’.
Hence iron reactivity is more than copper.

Question 9.
Draw a diagram of an activity of heat conduction by metals. Why iron, copper and aluminium are used to prepare in the manufacturing of cooking vessels?
Answer:

Iron, Copper and aluminium cooking vessels are preferred due to their high heat conductivity.

AP State Board Syllabus AP SSC 10th Class English Textbook Solutions Chapter 1A Attitude is Altitude Textbook Questions and Answers.

AP State Syllabus SSC 10th Class English Solutions Chapter 1A Attitude is Altitude

10th Class English Chapter 1A Attitude is Altitude Textbook Questions and Answers

Look at the pictures and answer the questions.

Question 1.
What qualities have made these persons great?
Answer:
The persons in the above pictures are Sudha Chandran, Stephen Hawking and Helen Keller.
Sudha Chandran is an accomplished Bharatanatyam dancer, Indian film and television actress, who showed great courage even though she had lost her leg in an accident.

Stephen Hawking is one of the famous scientists. Despite his debilitating illness, he has done ground-breaking work in physics.

Helen Keller overcame the adversity of being blind and deaf to become one of the 20th century’s leading humanitarians.
These three great persons showed that anything can be done, if one tries hard enough. From their lives, it is understood that one need not lose hope. Their lives show us that disability need not prevent one from reaching great heights. The qualities such as grit, determination, confidence, will power, dedication, discipline, etc. have made these persons great.

Question 2.
What qualities do you think a person requires to become successful ?
Answer:
The qualities a person requires to become successful are determination, dedication, discipline, grit, courage, faith, positive thinking, responsibility, hard work, commitment, desire, persistence, good character, etc. These qualities make a person highly successful.

Comprehension

I. Answer the following questions.

Question 1.
‘I call it my chicken drumstick,’ joked Nick. What does ‘it’ refer to? How does it help him ?
Answer:
‘It’ refers to the small foot that Nick has on his left hip. It helps him balance and enables him to kick. Nick uses his one foot to type, write with a pen and pick things up between his toes.

Question 2.
‘His parents decided not to send him to a special school.’ Was Nick happy about his parents’ decision? Why or why not? What do you think about this decision?
Answer:
Nick’s was not happy with his parents’ decision because there might be the risk of bullying. His companions at mainstream school might tease him.
But later, he realised that his parents’ decision was the best one. I think that this decision was the best one his parents could have made for him as he was able to achieve a degree in Financial Planning and Real Estate. The decision made him independent.

Question 3.
How did Nick’s parents help him to become independent?
Answer:
Right from the start Nick’s parents did their best to make him independent. His father put Nick in the water at 18 months and gave him the courage to learn how to swim. He encouraged Nick to get into football and skating. He taught Nick how to type with his toe at just six years old. Nick’s mother invented a special plastic device that meant Nick could hold a pen and pencil. Despite the risk of bullying, Nick’s parents insisted on his attending mainstream school.

Question 4.
Pick out the symptoms of Nick’s depression. Do you think his depression was normal or something unique about him? Give reasons for your opinion.
Answer:
Nick was deeply depressed when he was eight years old. When he was in depression, he went to his mother crying and told her that he wanted to kill himself. He felt cold and bitter. He hated God for doing this to him. He was terrified about his future without his parents. At age ten Nick tried to drown himself in the bath. These were the symptoms of Nick’s depression. I think his depression was normal. Any human being born like Nick might have the same depression.

Question 5.
Which incident in this text is funny? What makes it funny?
Answer:
Once Nick was in a car and a girl at traffic lights was looking at him interestingly. She could only see Nick’s head so he decided to do a 360 in the car seat to freak her out. When she saw the torso, she sped off really quickly. This is the funny incident in the text. The idea of Nick showing the girl his torso makes the scene funny.

Question 6.
What made Nick choose Bethany Hamilton as his teacher to learn surfing?
Answer:
Nick went to Hawaii in 2008 and met surfing master Bethany Hamilton. She had her arm bitten off by a shark when she was 12. Nick chose Bethany Hamilton as she too was a disabled person and still she performed surfing very well. Though she had no arm she did well. As a disabled person, she could know how a disabled person could learn how to surf. She could know the psychological condition of a disabled person.

Question 7.
Which aspect of Nick’s physical condition helps him to do a 360 degree spin?
Answer:
Nick has a very low centre of gravity so he has got pretty good balance. This condition helps Nick to do 360 degree spin.

Question 8.
What are the distinct features of this text? List them.
Answer:

1. It is an autobiography.
2. Varied sentences are used.
3. Ideas are arranged in a logical sequence.
4. Emotive and persuasive language is used.
5. Ideas are exemplified very well.
6. Cohesion is found in the text. The sentences are connected with proper linkers.
7. Unity of ideas is maintained for coherence. The sentences are connected in a clear and reasonable way.
8. Certain quotations and examples are given.
9. Proper introduction, development and conclusion are ensured.
10. The ideas are given formally and precisely.
11. As far as the content is concerned, it touches the emotions of a reader.
12. The content is message-oriented.
13. Physical description of the main character is given properly.
14. The main character’s attitudes, likes, dislikes, strengths and weaknesses are given effectively.

Question 9.
What do you learn from the life of Nick Vujicic?
Answer:
Nick Vujicic uses his life story to inspire people of all around the world. From the life of Nick, we learn that if we fail, we should try again and again until we succeed. Nick shows us that anything can be done, if we try hard enough. Undoubtedly, I feel that his life is a source of inspiration to everyone of us. He has been able to do all these because of his faith, hope, perseverance and strong will power. Nick proves that disability need not prevent one from reaching great heights. Hence I learn that we shouldn’t lose our faith and hope under any circumstances.

II. Given below are some of the statements made by Nick Vujicic. Which of these are substantiated by Nick’s life ?

• I realised why God had made us like this – to give hope to others.
• I wanted to concentrate on something good that / had.
• I tell people to keep on getting up when they fall and to always love themselves.
• If I can encourage just one person, then my job in this life is done.

Answer:
I think all the above statements are substantiated by Nick’s life.
i) I realised why God had made us like this – to give hope to others:
When Nick was 13, he read a newspaper article about a disabled man who had managed to achieve great things and help others. Nick was inspired very much by the disabled man mentioned in the article. He got a hope from him. Then he decided to use his life to encourage others and give them hope.

ii) I wanted to concentrate on something good that I had:
Nick was not discouraged with his disability. He knew that he had no arms and legs but he thought that they would never take away the beauty of his eyes. With his positive approach, he thought that his eyes were very good ones for him. He wanted to love his positive qualities such as faith, will power and perseverance. Further, he was quite satisfied with what he had, i.e. a small foot on his left hip. He said he would be lost with it.

iii) I tell people to keep on getting up when they fall and to always love themselves: If Nick fails, he tries again and again until he succeeds. When Nick was learning how to surf, he was terrified at first but later he did very well. Though he has no limbs, he always loves himself. I know this by his statement, “I decided to be thankful for what I do have, not get angry about what I don’t.”

iv) If I can encourage just one person, then my job in this life is done:
This statement was substantiated by Nick aptly. He encouraged many people in the world. He used his life story to inspire others. He made many people realise their inner beauty and personality. He was able to rise many people from the state of despair to the state of great hope.

Vocabulary

I. Look at the list of adjectives in the box. Which of them describe Nick Vujicic. Tick (✓) them.

Answer:

Explanation:

1. positive: hopeful and confident
2. negative: harmful, unpleasant or not wanted
3. optimistic: believing that good things will happen In the future
4. pessimistic: expecting that bad things will happen in the future
5. generous: willing to give money, spend time, etc. in order to help people or give them pleasure
6. nervous: worried or frightened about something
7. confident: sure that something will happen in the way that you want or expect
8. smart: fashionable, clever
9. sociable: friendly and enjoys being with other people
10. cowardly: not at all brave
11. courageous: brave
12. reliable: dependable
13. Independent: confident and able to do things by oneself in ones own way
14. dependent: needing someone or something in order to exist, be successful, be healthy, etc.
15. obedient: always doing what one is told to do
16.  trusting: willing to believe that other people are good and honest
17. valiant: very brave in difficult situation
18. self-centred: paying so much attention to oneself that one doesn’t notice what is happening
19. arrogant: behaving in an unpleasant or rude way
20. sarcastic: saying things that are the opposite of what one means, in order to make an unkind joke
21. quarrelsome: one who quarrels a lot with people
22. rude: not polite and annoys others
23. creative: good at using imagination to make things
24. stubborn: determined not to change one’s mind when people think one is being unreasonable
25. lazy: not making any effort to do anything
26. pompous: trying to seem magnificent or very important; fond of display, acting too proudly, self-important.
27. level-headed: sensible in making judgements

Pick out from the text the examples that support these attributes.

Attribute	Example from the text
1. Positive	In spite of his disability he has become great.
2. Optimistic	He always thinks, “If I fail, I try again, and again, and again. If I can encourage just one person, then my job is done.”
3. Generous	He spends most of his time delivering motivational speeches all over the world.
4. Confident	Though he has no limbs, he gains faith and hope and tries to give them to others.
5. Smart	He appears to be smart and shows his cleverness in learning things.
6. Sociable	He enjoys being with others by delivering speeches, playing football, golf, surfing, etc.
7. Courageous	Despite the absence of his limbs, he didn’t get discouraged. With great courage, he tries again and again and becomes a football player, a swimmer and a surfer.
8. Reliable	He is the most reliable person. As an Evangelical Christian he has faith and gives the same to others with his motivational speeches. The people believe his reliability and are attracted towards him.
9. Independent	He independently has done the things what he has wanted to do. e.g.: Playing football and golf, swimming, surfing, delivering speeches, etc.
10. Obedient	He seems to be obedient in accepting the unlucky birth.
11. Valiant	With great determination, he has reached a great position in his life. He becomes an international symbol of triumph over adversity.
12. Creative	He also plays golf with a club tucked under his chin.
13. Level-headed	He judges well when he says, “The challenges in our lives are there to strengthen our convictions. They are not there to run us over.”

II. Given below are words that describe the positive or negative attitude of a person. Discuss them with your partner and put a tick (✓) against the positive qualities and a cross (✕) against the negative qualities.

Answer:

Explanation:

1. sullen: angry and silent (negative quality)
2. sneaky: doing things in a secret and dishonest way (negative quality)
3. exuberant: happy and full of energy and excitement (positive quality)
4. bossy: always telling other people what to do in a way that is annoying (negative quality)
5. cautious: careful to avoid danger or risk (positive quality)
6. aggressive: behaving in an angry threatening way (negative quality)
7. competitive: determined or trying very hard to he more successful than other people (positive quality)
8. finicky: too concerned with unimportant details and small things that you like or dislike (negative quality)
9. imaginative: good at thinking of new and interesting ideas (positive quality)
10. observant: good or quick at noticing things (positive quality)
11. enthusiastic: showing a lot of interest and excitement about something (positive quality)
12. outgoing: someone who Is outgoing likes to meet and talk to new people (positive quality)
13. haughty: behaving in a proud. unfriendly way (negative quality)
14. intrepid: willing to do dangerous things; fearless, brave (positive quality)
15. malicious: very unkind and cruel and is trying to do harm to others (negative quality)
16. meticulous: very careful about small details and always makes sure that everything is done correctly (positive quality)
17. slovenly: lazy untidy and careless (negative quality)
18. obnoxious: very offensive, unpleasant or rude (negative quality)
19. stingy: not generous. especially with money (negative quality)
20. Idealistic: believing that one should live according to high standards and principles, even when they are very difficult to achieve (positive quality)
21. affable: friendly and easy to talk to (positive quality)
22. logical: reasonable and sensible (positive quality)
23. mean: cruel (negative quality)
24. cultured: intelligent, polite and interested in art, literature, music etc. (positive quality)

III. Tick (✓) the word/expression which is nearest in meaning to the word underlined in each sentence given below.

1. Water sports aren’t Nick’s only thing – he also plays golf with a dub tucked under his chin.
a) kept
b) pulled
c) covered
d) tied
Answer: a

2. His distraught mother couldn’t bring herself to hold him until he was four months old.
a) angry
b) careless
c) shy
d) anxious
Answer: d

3. Despite the risk of bullying, his parents insisted on Nick’s attending mainstream school.
a) discrimination
b) humiliation
c) negligence
d) failure
Answer: b

4. Nick, who was teased and bullied, had an electric wheelchair for mobility, and a team of carers to help him.
a) socialising
b) movement
c) travel
d) safety
Answer: b

5. Nick managed to pull through to become an international symbol of triumph over adversity.
a) disability
b) poverty
c) difficulties
d) opposition
Answer: c

6. The challenges in our lives are there to strengthen our convictions.
a) feelings
b) practices
c) beliefs
d) characters
Answer: c

IV. Read the following descriptions about persons and fill in the blanks with the words that match with these descriptions.

1. Ashok is a very unpleasant and rude fellow. I don’t talk to him. He is ———–.
2. Srinu is very confident, elegant and polite. But sometimes he does not appear to be sincere. He is ———–.
3. Sujatha is quiet and calm. She doesn’t like to spend time with others. She is interested in her thoughts and feelings. So she is an ———–.
4. Ramesh is very sensitive. He always shows sympathy for people who are suffering. He is ———–.
5. My neighbour is such a person that he has a feeling of hatred for others. He desires to hurt others’ feelings. He is ———–.
6. My father pays careful attention to every detail. He makes thorough planning for everything in our home. He is ———–.
7. Prem is an extremely unpleasant person. He always tries to offend people. He is ———–.
8. My mother is very calm and peaceful. She doesn’t get excited or irritated easily. She is ———–.
9. Rahul is a very lively and confident person. He enjoys being with his friends. He is an ———–.
10. Sridhar is always afraid of speaking in the class. He is ———–.
Answers:
1. boorish
2. suave
3. introvert
4. compassionate
5. malicious
6. meticulous
7. obnoxious
8. placid
9. extrovert
10. timid

GRAMMAR

I. Read the text again and identify some more Defining and Non-defining Relative Clauses.

1. —————————————————————
2. —————————————————————
3. —————————————————————
4. —————————————————————
5. —————————————————————
Answer:
1. Nick has a small foot, which helps him balance. (Non-defining Relative Clause)
2. Nick, who was born in Melbourne, now lives in Los Angeles. (Non-defining Relative Clause)
3. I read about a disabled man who had managed to achieve great things and help others. (Defining Relative Clause)
4. I decided to give people the courage that the article had given me. (Defining Relative Clause)
5. Nick, who later achieved a degree, says this. (Non-defining Relative Clause)

II. Read the following sentences and circle the Non-defining Relative Clauses and put a comma/a hyphen wherever necessary.

1. The meeting which was held in the town hall was a great success.
2. The people who live in glass houses must not throw stones.
3. The teachers who have taught Abhiram say that he is an exceptionally creative student.
4. Napoleon who won the French honour died at St. Helena.
5. The silk sarees which are made in Banares are popular all over the world.
Answer:
1. The meeting which was held in the town hall was a great success. (Defining Relative Clause)
2. The people who live in glass houses must not throw stones. (Defining Relative Clause)
3. The teachers who have taught Abhiram say that he is an exceptionally creative student. (Defining Relative Clause)
4. Napoleon, who won the French honour, died at St. Helena. (Non-defining Relative Clause)
5. The silk sarees which are made in Benares are popular all over the world. (Defining Relative Clause)

III. Complete the sentences with Defining or Non-defining Relative Clauses.

1. This is the peaceful place __________________________ .
2. The Mahaprasthanam’ is a popular book __________________________ .
3. Suresh ____________________________ has left the school just now.
4. Is this the street _______________________________________________ ?
5. The express __________________________________ has just arrived.
6. The place ___________________________ has been closed to traffic.
7. This is a famous engineering college _____________________________ .
8. My sister_______________ has secured ajob as an engineer in BHEL.
9. The theatre _____________________________ was designed by Mr Rao.
10. Viswanath is one of the outstanding directors in Telugu film industry______________________ .
Answer:
1. This is the peaceful place that is liked by every naturalist.
2. The Mahaprasthanam’ is a popular book which I have bought in Hyderabad.
3. Suresh, who is mv cousin, has left the school just now.
4. Is this the street where meat is sold?
5. The express which runs between Delhi and Chennai has just arrived.
6. The place which is behind our house has been closed to traffic.
7. This is a famous engineering college that is founded by Mr. Yashwanth.
8. My sister, who has completed her education in Bengaluru, has secured a job as an engineer in BHEL.
9. The theatre which was built in 2012 was designed by Mr. Rao.
10. Viswanath is one of the outstanding directors in Telugu film industry which produces a number of creative directors.

WRITING

I. Writing a biographical sketch

A biographical sketch is an account of the life and activities of an individual. It includes information about the person’s name, place of residence, education, occupation, life and activities and other important details. It is written by another person. If a person writes an account of his/her own life, it is called an autobiography.

Given below in the table is the biographical information about Stephen Hawking. Based on this information write a biographical sketch.

Points to be covered	Details of the person
Date and place of birth	January 8,1942, Oxford, England
Information about the family	Eldest one of four sons Mother: Isobel Hawking Father: Frank Hawking, a medical researcher with a speciality in tropical diseases
Important events in life	Early academic life: recognized as a bright student High school years: third from the bottom of his class Pursuits outside of school: loved board games, constructed a computer out of recycled parts at the age of 16, solved rudimentary mathematical equations Marriage: married Jane Wilde Health: Suffered from Amyotrophic Lateral Sclerosis Research: on black holes Discovery: Hawking Radiation
Awards, prizes, honours	Fellow of the Royal Society at the age of 32 Albert Einstein Award. The Pius XI- Gold Medal for Science from Pope Paul VI in 1975
Contribution to his field and society	Contributed to the advancement of science and research

Answer:

Biographical Sketch of Stephen Hawking

Stephen William Hawking is one of the greatest scientists of the world. He was born at Oxford in England on 8 January, 1942 to Isobel Hawking and Frank Hawking. He was the eldest of four sons. His father, Frank Hawking, was a medical researcher with a speciality in tropical diseases.

Hawking was recognised as a bright student. But he was not initially successful academically. During his high school years, Stephen stood the third from the bottom of his class.

Hawking used to remain with a close group of friends with whom he enjoyed board games, the manufacture of fireworks, model aeroplanes and boats. With the help of the mathematics teacher, Dickran Tahta, Hawking and his companions built a computer from clock parts, an old telephone switchboard and other recycled components when he was 16. Hawking solved rudimentary mathematical equations.

He married Jane Wilde on 14 July, 1965. The first years after their marriage were hectic. Hawking has achieved many things in the field of science in spite of his prolonged illness. He has been suffering from an incurable disease, Amyotrophic Lateral Sclerosis (ALS) which has weakened his muscles since he was 17 years old.

Stephen Hawking is known for his work regarding black holes and for authoring several popular science books. In 1974, Hawking’s research turned him into a celebrity within the scientific world when he showed that black holes are not the information vacuums that scientists had thought they were. In simple terms, Hawking demonstrated that matter, in the form of radiation, can escape the gravitational force of a collapsed star. Thus Hawking Radiation was invented.

As a mark of his eminence, Professor Hawking obtained twelve honorary degrees which he deserved. He was named a Fellow of the Royal Society at the age of 32, and later earned the prestigious Albert Einstein Award. In 1975, Hawking journeyed to Rome, where he was honoured with the Pius XI – Gold Medal for science from Pope Paul VI in 1975.

Attitude is Altitude Summary in English

This is the story of a great person, Nicholas James Nick Vujicic, who stands as an inspiration to other people with his great qualities-faith, will power and perseverance- even though he is a disabled person. His disability has not stopped him from doing what he has wanted to do. Nick Vujicic was born on 4 December 1982 in Melbourne, Australia with a rare disability called Phocomelia characterised by the absence of all four limbs. Despite the absence of his limbs, he plays football and golf, swims and surfs. He is an Australian Christian evangelist and motivational speaker. As a child, he struggled mentally and emotionally as well as physically. It was a shock to Nick’s parents that he was born without limbs. His mother was a nurse and his father was a computer programmer and accountant. His parents did their very best when they decided to send him to mainstream school despite the risk of humiliation.

Nick has a small foot on his left hip. It gives him balance and enables him to kick. With his foot, he writes with a pen and picks things up between his toes. He also plays golf with a heavy stick tucked under his chin. He is a huge fan of the English Premier League. His parents did their best to make him independent from the start. His father gave him the courage to learn how to swim by putting him in water at 18 months. His mother invented a special plastic device to enable him to hold a pen and pencil.

At age eight, Nick was deeply depressed and went to his mother crying. He told her that he wanted to kill himself. When he was ten years old, he decided to end his life by drowning himself in a bathtub but luckily he was unsuccessful in his attempt. When Nick was 13, he was inspired when he read about a disabled man who had managed to achieve great things and helped others. He understood that God had given him the life to give hope to others and so he decided to use his life to encourage other people and give them the courage. He believes that challenges strengthen our opinions. With the help of his religion, friends and family, Nick becomes an international symbol of triumph over adversity. Nick won the Australian Young Citizen of the Year award in 1990 for his bravery and perseverance. His persistence made him achieve a degree in Financial Planning and Real Estate. He went to Hawaii in 2008 and was trained in surfing by Bethany Hamilton. Nick was on the cover of Surfer magazine with his feat of doing the 360 degree spins. He is able to do this feat because of his low centre of gravity.
Nick and Kanae Miyahara, whose mother was a Mexican and father was a Japanese, got married on February 12, 2012 and on February 13, 2013 they were blessed with the birth of a healthy baby boy with full body.

Nick has travelled to over 24 countries speaking to groups of up to 110,000 people. He keeps telling the people to keep on getting up when they fall and to always love themselves. He spreads his messages of faith and hope around the world.

Nick uses his story to inspire and inform people all around the world. Nick presents values, principles, attitudes and perspectives that challenge and equip people from all walks of life to overcome their adversities.

Attitude is Altitude Glossary

stretch (v): to straighten one’s arms, legs or body

wrap (v): put ones arms around something

skateboard (n): a short narrow board with small wheels at each end, which you stand on and ride as a sport

torso (n): the main part of the body, not including the head, arms or legs

surf: to take part in the sport of riding on waves on a surfboard

despite (pre): In spite of

limb (n): an arm or leg

hip (n): one of the two parts on each side of one’s body between the top of one’s leg and one’s waist

chicken drumstick (n): the lower part of the leg of a chicken or other bird that is cooked and eaten as food

faith (n): belief or trust in God

virgin (n): someone who has never had sex

modest (adj): shy about attracting sexual interest

publicist (n): someone whose job is to make sure that people know about a new product, film, book, etc.

club (n): a heavy stick with one end thicker than the other

tuck (v): to put something into a space

distraught (adj): so upset and worried

bully (v): to threaten to hurt someone or frighten them

bullying (n): humiliation

carer (n): someone who looks alter an old or ill person at home

wall-mounted (adj): attached to a wall

pump-action (adj): a pump-action piece of equipment is operated by pulling or pressing a part in or out. so that the contents come out in short bursts

drown (v): to die from being under water for too long time

lack: to not have something that one needs

triumph (n): an important success or victory

adversity (n): a difficulty or unpleasant situation

Inspirational (adj): providing encouragement or new ideas for what one should do

conviction (n): a very strong belief or opinion

run over (phr.v.): to hit someone or something with something (a vehicle, challenge, etc.) and drive over them

perseverance (n): the quality of continuing to try to achieve a particular aim despite difficulties

give somebody the eye (n.phrase): to look at someone in a way that shows one thinks they are sexually attractive

freak out (phr.v.): make someone very anxious. upset or afraid

amazing (adj): (here) very good

spin (n): an act of turning around quickly

centre of gravity (n.phrase): the point in any object on which it can balance

AP State Board Syllabus AP SSC 10th Class English Textbook Solutions Chapter 2A The Dear Departed Part 1 Textbook Questions and Answers.

AP State Syllabus SSC 10th Class English Solutions Chapter 2A The Dear Departed Part 1

10th Class English Chapter 2A The Dear Departed Part 1 Textbook Questions and Answers

Look at the pictures and answer the questions.

Question 1.
What do you understand from the picture?
Answer:
The rat is pointing a pistol at the cat and intimidating him. I understand that it is a funny picture. One can easily open one’s lips without knowing to smile on seeing this unusual picture.

Question 2.
Can you recall anything comic associated with these animals?
Answer:
The most popular comic Tom and Jerry’ is associated with them.
‘Tom and Jerry’ is a series of animated cartoon films. We find humour with the rivalry between a cat (Tom) and a mouse (Jerry), Tom’s chasing Jerry and slapstick scenes. “Tom’s making numerous attempts to capture Jerry which leads to destruction” – it creates fun. The scenes such as slicing Tom in half, shutting his head in a window or a door, stuffing Tom’s tail in a mangle, kicking him into a refrigerator, plugging his tail into an electric socket, sticking matches into his feet and lighting them, etc. amuse all the viewers.

(Or)
Yes. I can recall an incident which happened a long time ago in my old house. We used to see many mice in our old house because we stored paddy bags in the house. One day our pet cat jumped on a little mouse which was eating the paddy grains. The little mouse began running. Our cat ran after it. The funny thing was that the mouse did not run away from the place. It began running around the paddy bags. After some time both the cat and the mouse stopped running as they were tired much. At that stage 1 interfered and drove the cat away to save the life of the rat.

Question 3.
Can you imagine, what may be the conversation between the rat and the cat?
Answer:
Conversation between the rat and the cat:
Rat : Hands up!
Cat : Don’t shoot me. I will not eat you.
Rat : No, I don’t believe you. You are cruel.
Cat : Believe me. I decided not to eat rats.
Rat : I don’t believe you. You ran after me yesterday, didn’t you?
Cat : Yes. But not to kill you.
Rat : Then, why?
Cat : I just wanted to tell that I would not kill you thereafter.
Well, how did you get the pistol?
Rat : I stole it from the owner of the house last night.
Cat : Ok. Do you know how to shoot with it?
Rat : I will not tell you.
Cat : Ok. Bye.
Rat : Bye.

Comprehension

Answer the following questions.

Question 1.
What qualities of Mrs. Slater have you noticed?
Answer:
Mrs. Slater is unscrupulous, greedy, deceitful, dishonest, selfish, impolite and insensitive. She unfairly claims her father s things. This shows her unscrupulous and dishonest manner. She has shifted her father’s bureau and clock from his room before her sister’s arrival. Hence 1 can say Mrs. Slater is greedy. She wants to deceive her sister by pinching their father’s things. 1 can say that she is impolite and insensitive as she doesn’t even wait for her father s funeral and has started dividing things between them (the two sisters).

Question 2.
Why does Mrs. Slater decide to shift the bureau from her father’s room before the arrival of the Jordans? How does Henry react to the suggestion?
Answer:
Mrs. Slater wants to own her father’s bureau as he likes it very much. After her father’s death, she decides to shift the bureau to sitting room before the arrival of the Jordans. She thinks that her sister will lay a claim to it. At first, Henry is shocked at her decision. He feels that the two sisters should amicably divide their father’s things. Henry suggests her that it is not a good thing pinching her father’s things in an unfair way. Moreover, Henry is worried about the arrival of the Jordans while they are shifting the bureau.

Question 3.
Why do the Jordans take a long time to get to the house of the Slaters? What does it show about the two sisters’ attitude towards each other?
Answer:
I think the Jordans are late as they have bought mourning dresses to wear before they come to Slater’s house. They are not sorrowful at their father’s death but they are worried about their appearances and how they can come out to each other. In their relationship, we don’t find any kind of emotions and sisterly love.

Question 4.
Ben appreciates his father-in-law saying, ‘It’s a good thing he did’. Later, he calls him a ‘drunken old beggar’. Why does he change his opinion about his father-in-law?
Answer:
Ben appreciates his father-in-law saying it’s a good thing he did’ when he comes to know from Mrs. Slater that the old man has gone out to pay his insurance premium on the day of his death. Later, he comes to know that he has not paid the premium and therefore calls him a drunken old beggar’. Ben has changed his opinion about his father-in-law when be realises that he hasn’t paid premium because, now after his death, they can t claim the insurance company.

Question 5.
What made Mr.Henry feel shocked to hear Victoria say ‘Are you planning to pinch it ?’?
Answer:
When Victoria asked Slaters “Are you planning to pinch it ?”, Mr. Henry felt shocked. He thought that Victoria was innocent. But when she asked him the above question, Mr. Henry came to know that Victoria had wisdom beyond her age. He actually didn’t expect that question from his little daughter.He came to know that she was a precocious girl and had the ability to distinguish between good and bad.

The Dear Departed Part 1 Summary in English

The one-act play “The Dear Departed” by William Stanley Houghton is a satirical play that explores family relationships and the falsehood and hypocrisy and greed that often lie beneath it. The story exposes the sad fact that human beings often become dehumanized in the face of greed and minor material gains. This play satirizes the degradation of moral values in respect and care within the members of the family itself. This story clearly reveals how elderly people are mistreated. Stanley Houghton uses various literary devices to criticize basic human characteristics in his play. He uses irony, sarcasm, humour and a twist in the plot to criticize human traits. He tries to bring out the qualities of the two daughters called Mrs. Slater and Mrs. Jordan towards their father. He tries to show how the sisters are interested in the property of their father rather than to show true care and affection towards their father.

The story begins with Mrs. Slater telling her daughter, Victoria to change her dress before the arrival of her sister (Slater’s sister) Elizabeth and Elizabeth’s husband, Ben. Mrs. Slater’s husband, Henry has sent them a telegram with the message of the death of his father-in-law and Elizabeth and Ben are coming to talk over the old man’s affairs. Henry wonders if they would come at all because Elizabeth has said that she would never set foot in their house again. But Mrs. Slater says that her sister will come fast enough after her share of what their father has left. Mrs. Slater asks her husband to wear the new slippers of her father. She also suggests that they should replace their shabby old chest of drawers with the valuable bureau of her father which is in his bedroom. He agrees to do it after some hesitation. Mrs. Slater wants to do it before their arrival.

Mrs. Slater fastens the door and she and her husband carry the old chest of drawers upstairs. Henry is shocked when Victoria asks him if they are pinching grandpa’s bureau. He replies that grandpa has given it to her mother before his death. Mrs. Slater carries a handsome clock and puts it on the mantelpiece. Mrs. Slater and her husband carry the pretty old-fashioned bureau downstairs and put it in the place of the chest of drawers. At the same time Victoria ushers in Mrs. Jordan and Ben. Mrs. Jordan goes straight to Mrs. Slater and kisses her and the men shake hands. Mrs. Jordan remarks that their father has gone at last. Mrs. Slater replies that he is seventy-two a fortnight the previous Sunday. She tells them that the old man has been merry that morning and has gone out to pay his insurance. Ben and Mrs. Jordan remark that it is a good thing on his part.

According to Mrs. Slater, their father is found dead when she takes up a bit of something for him on tray.
Ben and Mrs. Jordan don’t want to look at the old man ; they prefer to have tea and so Mrs. Slater gets tea ready. They think of publishing the announcement of the death of the old man in the papers. Then they decide to look through the old man’s things and make a list of them. Mrs. Jordan tells that the old man has promised his gold watch to their Jimmy. Then Victoria tells them that grandpa hasn’t paid his insurance. Ben calls him “the drunken old beggar”. Both the sisters complain that they have to put up with their father for all those years. Then Mrs. Slater asks Victoria to go and bring the bunch of keys from grandpa’s room. Victoria is afraid to go but she does. After some time, she gets back very scared and tells them that grandpa is getting up. They are transfixed with amazement. The vigorous and well coloured old man Abel Merry weather comes in.

The Dear Departed Part 1 Glossary

lay (v): (here) to put the cloth, plates, knives, forks etc. on a table, ready for a meal

vigorous (adj): using a lot of energy and strength or determination

plump (adj): slightly fat in a fairly pleasant way

vulgar adj): rude and offensive

get her own way (idiom): persuade other people to allow you to do what you want

D’ye: Do you (used in awkward situations)

amazed (adj): very surprised

ages (n): long time

stooping (adj): bent towards and down

drooping (adj): hanging or bending down

come after (phr.v.): to look for someone to get something from them

worn out (adj): too old or damaged to be used

break down (phr.v.): stop working in a successful way

trifle (n): something unimportant or not valuable

precocious (adj): Intelligent/gifted/talented

bureau (n): a writing desk with drawers

drive a liard bargain (idiom): work hard to negotiate agreements in on&s own favour

startled (v): made someone suddenly surprised or slightly shocked

stupefied (adj): so surprised, tired or bored thai one cant think clearly

daft (adj): stupid/silly

shabby (adj): untidy and bad

fasten (v): to firmly close a window, door etc. so that it will not open

pinch (w): steal

mantelpiece (n): a shelf projecting from the wail over the fireplace

usher (v): lead/show the way/welcome

appeal: be attractive

stagger (v): to walk or move unsteadily, almost falling over

complacent (adj): sell-satisfied/unconcerned

mourning (n): feeling of sadness to miss someone after they have died

fortnight (n): two weeks

chirpily (adv): cheerfully and actively

snug (adj): warm and comfortable

wipe (v): to rub a surface with something in order to remove liquid, dirt, etc.

look through (phr.v.): look for something

overdue (adj): not paid by the expected time

annoy (v): to make someone feel slightly angry and unhappy about something

put up with (phr.v.): to accept an unpleasant situation or person without complaining

swindling (v): cheating somebody for property or money

reluctantly (adv): unwillingly

AP State Syllabus AP Board 8th Class Physical Science Solutions Chapter 12 Stars and the Solar System Textbook Questions and Answers.

AP State Syllabus 8th Class Physical Science Solutions 12th Lesson Stars and the Solar System

8th Class Physical Science 12th Lesson Stars and the Solar System Textbook Questions and Answers

Improve Your Learning

Question 1.
What is your local noon time?
Answer:
The time when the shortest shadow of a vertical object occurs in a particular place is called local noon time at that place.

Question 2.
Where do you find moon at night?
a) 2 days before Poumami
b) 2 days after Amavasya
Answer:
a) Couple of days (2 days) before full moon day (Pournami), a crescent is seen in the west just after sunset.
b) Couple of days (2 days) after the new moon day (Amavasya), a crescent is seen in the west just after sunset.

Question 3.
Why doesn’t eclipse occur on every full moon day or on every new moon day?
Answer:
Lunar eclipse can happen during a full moon and only when the moon and earth and sun are directly in line and the moon passes through the earth shadow. Most of the time the moon is slightly out of line and that is why we don’t have a Lunar eclipse every full moon.

Question 4.
Where do you find the pole star?
Answer:
The pole star lies on the line joining the two outer stars of the constellation great bear. Pole star directly above the north pole of earth.

Question 5.
What Is the difference that you find between pole star and other stars?
Answer:
If we observe the position of various stars constantly. We will notice that they are not in a fixed position because as the earth rotates about a fixed axis, the position of stars with respect to earth changes. But the position of pole star does not change with respect to earth.

Question 6.
Why does polestar seem to be stationary?
Answer:
The polestar is situated in the direction of the earth’s axis and that is why it does not appear to move even though all stars appear that they are moving because of ie rotation of earth. So pole star seems to be stationary.

Question 7.
Name some constellations.
Answer:
Names of some constellations:

1. Great bear (Saptarishi)
2. Cassiopeia (Sharmistha)
3. Orion
4. Leo (Simha)
5. Corona
6. Borealis

Question 8.
How many planets are there in our solar system? What are they?
Answer:
There are 8 planets in our solar system. They are:

1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus and
8. Neptune.

Question 9.
Look at the below table and name the smallest and the biggest planets in our solar system.

Answer:
From the table the biggest planet is Jupiter and the smallest planet is Mercury.

Question 10.
Among all 8 planets what is the special thing about earth?
Answer:
The special thing about earth is it is the only planet in the solar system on which life is exist.

Question 11.
How do day and night occur?
Answer:
The day and night occur due to rotatory motion of earth.

Question 12.
Do the stars appear moving? How can you say?
Answer:
Yes, stars are appear moving. Our galaxy like all other spiral galaxies is rotating. The stars move on orbits around the centre of the galaxy. It was the motions of stars in external galaxies that lead to the idea of dark matter in the universe. Stars also have some random motions. They do not orbit galaxy in exact circles. As observers we see this motion of the stars as what is called proper motion, the projection of their velocity on to the plane of the sky is radial motion.
Normal Answer : Alternate answer is No. All the stars appears that they are moving because of rotation of earth.

Question 13.
Is it possible to see the polestar for the people who live in the southern hemisphere of the earth? Why?
Answer:
A pole star is a visible, preferably a prominent one, that is approximately aligned with the earth’s axis of rotation. The term polestar refers to polaris which is the current northern pole star also known as the north star. So the people in southern hemisphere unable to see this pole star.

Question 14.
What is the use of artificial satellites in our daily life?
Answer:
Artificial satellites have many uses in daily life.

1. They are used for forecasting weather.
2. They are used for transmitting television and. radio signals.
3. They are also used for telecommunication.
4. They are used in aviation and military (these satellites are called remote sensing which will collect information from a distance).

Question 15.
Why is Venus the brightest planet?
Answer:
Venus is very bright that’s partly because sunlight easily reflected by acidic clouds that blanket the planet atmosphere and also it is closest planet to earth.

Question 16.
Are you curious about going to the moon? Why?
Answer:
Yes, I am curious about going to moon. Because I want to find answers raised in my mind.

1. Is it true there is no life on moon?
2. If it does not have atmosphere, how it look like?
3. How earth look like from moon?
4. Whether there are any mountains on moon or not?
5. There may be any creators on moon or not?
6. Whether there is any form of water exists on moon?
7. Whether we able to walk on moon as freely as on earth surface?

Question 17.
While observing the shadow of a stick from morning to evening, some questions arose in Ramya’s mind. What may be those questions?
Answer:

1. Why sun is changing its position from morning to evening?
2. How does the length of the shadow change with time?
3. Why we are getting longest shadows in the morning and evening?
4. Why the shadow in the noon is shortest?
5. Do all the days at noon have same size of shadow?

Question 18.
What are the questions that engage your mind when you look at night sky?
Answer:

1. Is stars collide with each other?
2. Where does the stars go in the morning?
3. Whether stars daily travel in the same path?
4. Why night sky is black and early morning sky is blue?
5. Whether we can count stars in the sky?
6. Why stars grouped to form constellations?

Question 19.
Even though we do not have clock, we can know the time by observing some shadows in daytime. Think and discuss with your friends how we can know the time at night?
Answer:
We can know the time by position of moon and stars or with reference to pole star. Estimation of time by using position of moon:

1. If the moon is full do the experiment stop if it is new moon.
2. Imagine the moon is divided into 12 vertical strips. First hour at right edge and last hour at left edge. It can vary by season or location.
3. Read the moon from left to right following an imaginary horizontal half line.
   Look for where the line intersects the boarder between light and dark. Make a note of which strip that intersection is in.

For example:
The instruction is at 8 pm and transition from right to left is from light to dark. This tells us the moon will set in the west at 8 pm.
This moon will set at about 7-8 hours after sunset. If sunset is at 8 pm. You can expect moon time is at 3-4 am.

Question 20.
How can you find north – south direction at your place?
Answer:
This experiment should be performed on a day when the sky is clear, preferably between nine in the morning and four in the evening.

Pick a spot in open ground away from buildings and trees. The spot should be as flat as possible.
Take a stick which is a little over a meter long and fix it vertically in the ground. Ensure that exactly one meter of stick remains above the surface of ground. Build a fence around your stick as shown in figure.
Make your first observation at nine in the morning, Make a mark with a nail or peg at the point where the tip of the shadow falls on ground. Measure the length of the shadow.
Then, make similar observations for every half an hour throughout the day till four in the evening.
Find the direction of shortest shadow cast by vertical object on the ground. That gives the north-south direction.

Question 21.
In which direction (towards north or south) is the sun moving day by day when you read this lesson?
Answer:
From December 21 to till June 21 the sun appears to shift northward. From June 21 to December 21 the sun appears to shift southward.
(Basing on this information we have to give the answer suppose you have read the lesson in the month of February the sun is moving towards north direction).

Question 22.
What are the planets you have seen in the sky? When do you observe those planets?
Answer:
The two planets observe in the sky are

1. Venus: Sometimes Venus appears in the eastern sky before sunrise. Sometimes it appears in the western sky just after sunset. Therefore it is often called a morning or an evening star.
2. Mars: It appears slightly reddish and therefore, it is also called red planet. It appears in the east.

Question 23.
What is the duration of a day and night today? Collect the information about duration of day and night for the past 7 days from the newspapers, analyze it and say whether summer or winter is going to come.
Answer:
Students have to collect the information from newspaper and other resources.
(Hint: If sun is shifting towards south the upcoming season is winter if it is shifting towards north the upcoming season is summer).

Question 24.
What are the other districts on the same latitude as your district ?
Answer:
I am residing at Krishna district. The latitudes of Krishna district are 16. The other districts which have same latitude are West Godavari, Mahaboobnagar.
(You should write the latitude of your district and you have to find out the districts which lie in that latitude from table -1 on page 163 of textbook.)

Question 25.
Collect the information about cosmic dust (wastage) from newspapers, internet and make a poster on your school panel board about the consequences of cosmic dust.
Answer:
Cosmic dust: Cosmic dust is a type of dust composed of particles in space which are a few molecules to 0.1 mm in size.
Consequence of cosmic dust:
The orbit of space junk could deteriate resulting in the junk falling to earth. If it survives and reaches the earth’s surface it would cause the same damage as equally sized meteorite, including damaging or destroying structures in the area killing people, etc.
The earth receives hundreds of tonnes of space dust, rocks, etc every week. If you were to get whole load of it in one place and try and breathe it in it probably would be harmful. However natural concentrations are so low that it possess no risk.

Question 26.
Make a sundial. Explain how you made it.
Answer:
Making of sundial:
Cut a right angled triangle ABC from a sheet of cardboard. Angle C of the triangle should equal to the latitude of your city or town and angle A should be 90° as shown in figure.

Fix cardboard triangle vertically in the middle of a rectangular wooden board. Glue strips of paper along both edges of BC and the wooden board to make the triangle stand erect.
Place your board with the triangle on level ground in an open space which gets sunlight throughout the day. Base BC of the triangle should be placed in the north- south direction, with B pointing to the north.
At nine in the morning, draw a line along the shadow of side AC on the wooden board. Write the time along side of the line. Draw lines of the shadow of side AC at one hour intervals through the day till sunset and mark the time for each line. The sundial is now ready.

Question 27.
Draw the different phases of moon. Arrange them in an order from poumami to amavasya.
Answer:

Question 28.
Draw the location of polestar showing the direction from Great Bear.
Answer:

Question 29.
Draw the diagram of the solar system.
Answer:

Question 30.
How do you appreciate the construction of knowledge about the universe by our ancestors?
Answer:
They study of our universe changed from time to time from earth is flat to higgs bosan particles. All these secrets about our universe are revealed due to constant afforts of our ancestors. That is due to construction of knowledge about the universe by our ancestors. So the afforts of our ancestors should be thoroughly appreciated.

Question 31.
We launched so many artificial satellites around our earth for different purposes. What do you think about the impact of artificial satellites and their radiation on bio-diversity?
Answer:
Effect of radiation released from artificial satellites on biodiversity:
I. Animals and humans:

1. Killing certain enzymes in the body can simply make sick.
2. If radiation damages DNA, the body may not repair it. It increases the chances of both animals and humans developing cancer.

II. Marine animals: High level of radiation cause a reduction and reproduction capabilities of marine animals.
III. Plants: Weaking of seeds and frequent mutations. Excess of radiation killing plants.

Question 32.
Among eight planets of our solar system, earth is the only planet supporting life. Explain how we should protect our earth and its environment.
Answer:
Steps to be taken to protect earth and environment:

1. Reduce pollution by reducing air, water and land pollution.
2. Recycle resources by sending the degradable like paper and non degradable like plastic and glass objects to recycling factory.
3. Save resources by using them carefully. E.g.: Water, trees, wood, paper.
4. Stop burning fossil fuels (Coal, oil and natural gas) for that do not waste electricity.
5. Plant lot of trees.

8th Class Physical Science 12th Lesson Stars and the Solar System InText Questions and Answers

8th Class Physical Science Textbook Page No. 160

Question 1.
What are the celestial objects that we can see in the sky?
Answer:
Stars, Planets, Moon (Satellite), Comets, Meteors and Meteorites are the celestial objects that we can see in the sky.

Question 2.
Are the stars moving?
Answer:
Yes, the stars are moving.

Question 3.
Do you see the same stars at night and early in the morning?
Answer:
No, we do not see the same stars at night and early in the morning.

Question 4.
Do you see the same stars during summer and winter nights?
Answer:
Yes, it is due to the change of axis of rotation of the earth.

Question 5.
What is the shape of the moon? Why does it change? Why doesn’t the sun change its shape daily like the moon?
Answer:
The actual shape of the moon is approximately spherical.
But it changes everyday.
The sun does not change its shape like the moon due to its size and the distance it is away from the earth. Moreover the shadow of the earth falls on one side of the moon partially or fully. This makes the changes in its shape. Also the moon does not have its own light to make the shadow of the earth to fall on the huge sun.

Question 6.
Where exactly is the sun situated in the sky at noon?
Answer:
Above our head (vertically above) (Really the sun does not revolve around the earth but due to the rotation and revolution of the earth we feel / imagine that the sun moves around the earth.)

Question 7.
Why does the shadow of a tree change from morning to evening?
Answer:
Due to the rotation of the earth we find the sun at different positions in the sky which brings the tree the different shadows from morning to evening.

8th Class Physical Science Textbook Page No. 168

Question 8.
Will we be able to hear any sound if we were on the moon? Why?
Answer:
Sound required a medium for its propagation. There is no atmosphere (medium) on moon. We know sound cannot travel in vacuum. So we unable to hear any sound if we were on the moon.

Question 9.
Can any life exists on the moon? Why?
Answer:
Moon does not have air (oxygen) and water which are essential for existence of life. So there is no life exists on moon.

8th Class Physical Science Textbook Page No. 169

Question 10.
Why does lunar eclipse occur only on a full moon day?
Answer:
Lunar eclipse occur only on a full moon day because lunar eclipse happen when the earth’s shadow falls on the moon, hiding it from the sun’s light. For this to happen, the moon must be on the opposite side of the earth from the sun. So the full half of the moon that is lit by the sun is visible from earth that is full moon day.

Think and Discuss

8th Class Physical Science Textbook Page No. 161

Question 1.
Look at the nails or pegs you have fixed on the ground to keep track of the shadow of the stick throughout the day. From their positions, can you tell how the position of the sun changes in the sky from sunrise to sunset?
Answer:
The position of sun changes from slanting to vertical and then vertical to slanting.

8th Class Physical Science Textbook Page No. 163

Question 2.
Why does the sun appears to travel towards north or south? Try to find the answer by reading your social studies chapter “Earth movements anti seasons” along with this lesson.
Answer:
The earth’s tilt is constant 23.5 degree perpendicular. The earth position relative to sun changes, not the tilt itself during orbit. The sun is moving towards north throughout summer because the north pole is tilted 23.5 degree towards sun and we are in northern hemisphere. During the winter the south pole is tilted 23.5 degree so the sun appear to travel towards south.

8th Class Physical Science Textbook Page No. 168

Question 3.
Scientists are planning to build settlements on moon and are trying to make arrangements to live there. You know that there is no air on moon. How will it be possible to live on the moon then?
Answer:
Oxygen is essential for humans. Unless we built special structures and buildings on the moon and put oxygen into them, we would not able to live on the moon without wearing oxygen tanks all the time.

8th Class Physical Science Textbook Page No. 178

Question 4.
The diameter of the sun is 13,92,000 Km. The diameter of the earth is 12,756 Km. The diameter of the moon is 3,474 Km. The distance from the sun to earth is 15,00,00,000 Km. The distance from the earth to moon is 3,84,399 Km.
Take the scale as 1 lakh km = 1 cm, and imagine how the arrangement of sun, earth and moon is in our universe. Can you make this arrangement on your school ground?
Answer:
Yes, we can do it in our play ground. Placing sun at the middle. Rotating earth around sun and rotating moon around earth by measuring diameters in cm.

8th Class Physical Science 12th Lesson Stars and the Solar System Activities

Activity – 1

Question 1.
Observing the changes in the length of shadow.
This experiment should be performed on a day when the sky is clear, preferably between nine in the morning and four in the evening.

Pick a spot in the open ground away from trees and buildings.
The spot should be as flat as possible. Take a stick which is a little over a meter long and fix it vertically in the ground. Ensure that exactly one meter of stick remains above the surface of ground.
Make your first observation at nine in the morning. Make a mark with a nail or peg at the point where the tip of the shadow falls on ground. Measure the length of the shadow.
Then, make similar observations for every half an hour throughout the day till four in the evening.
Use a clock to fix the time for making your observations. Enter the measurements of the length of the shadow and the time of measurement in a table making two columns, one for time and another for length of shadow.

Time	Length of the shadow
9.00 am	1.75 m
9.30 am	1.7 m
10.00 am	1.6 m
10.30 am	1.5 m
11.00 am	1.1 m
11.30 am	0.8 m
12.00 noon	0.7 m
12.30 pm	0.81 m
1 pm	1.12 m
1.30 pm	1.3 m
2.00 pm	1.5 m
2.30 pm	1.75 m
3.00 pm	1.84 m
3.30 pm	2.2 m
4.00 pm	2.5 m

(These values are changes from place to place and with seasons)
a) Look at your table and figure out the time of the day of shortest shadow.
Answer:
I observed at 12 noon.

b) When did you observe the longest shadow in your activity?
Answer:
At 4 pm.

c) How does the length of the shadow change with time? Illustrate your answer with the help of some diagrams. Draw the diagrams of the stick and its shadow for 5 different times, that is, at 9am, 1 lam, 12noon, 2pm and 4pm.
Answer:
The size of the shadow decreases and reach a minimum and then increases (It has minimum value at 12 noon)
(Students have to draw the diagrams of the stick and its shadow at 9 am, 11 am, 12 noon, 2 pm and 4 pm by doing this activity)

d) If you continue your activity from sunrise to sunset, at what times do you think the shadow would be the longest?
Answer:
At sunrise and at sunset.

e) Where is the sun situated in the sky at noon? Where does the shadow of stick is fall at that time? Think about how your own shadow will be at that time.
Answer:
Almost in line with the stick. It will falls in north-south direction. My own shadow is also in north-south direction.

f) Do you think that your shadow length will be the same on all the days at noon?
Answer:
Yes, the shadow will be same on all the days (with in two weeks).

g) In which direction does the shortest shadow of the stick fall in your activity?
Answer:
The shortest shadow falls in the north-south direction.
Continue your observations.

h) Observe on the next day whether the shadow of the stick falls at the same spots at the same times throughout the day.
Answer:
Yes, it falls on the same spot.

i) Can you use your stick as a clock (sundial) to tell the time? If your answer is ‘yes’, explain how this is possible.
Answer:
Yes, due to movement of sun from east to west.

j) Two weeks later, once again check to see whether the stick’s shadow falls at the same spots at the same times during the day.
Answer:
It fall on the same spot. But length of shadow change.

k) If the shadow does not fall on the same spot, what could be the possible reason?
Answer:
The position of the sun in the sky changes during the day.

l) If you continue the experiment the position of shadow changes or not ?
Answer:
No, it does not change. The position of sun changes from day to day as well.
That is, the position of the sun at 10.00 am today will be different from its position two weeks later at the same time. If you choose a particular time every week and mark the position of the sun with a peg at that time, you can build a calendar for the full year.

m) During a period of two weeks you had made an observation that the length of the shadow at a particular time is changing day by day. Did it become longer or shorter?
Answer:
Yes, it is changing day by day. During summer it is shorter day by day and during winter it is larger day by day.

n) By observing the direction of shadows, can you guess the arrival of summer or winter?
Answer:
Yes.

Activity – 2

Question 2.
Understanding the north-south movement of the sun.
Fix a spot near your home from where you can observe the sunrise. You may have to go to the terrace of a RCC building or go to an open field for the purpose. Choose a tree or an electric pole or some other stationary object as a reference point.

Over the next 10 to 15 days, note the spot at which the sun rises daily, keeping in mind your reference point. Make a daily sketch of the rising sun as well as your reference point in your notebook during this period.
a) Does the spot of sunrise change? If it does, in which direction does it seem to move?
Answer:
It may moves towards south of the sky if it is Dakshinayanam or it may moves towards north of the sky if it is Uttarayanam.
(So answer based upon Uttarayanam or Dakshinayanam)

b) Was the sun appear travelling towards south or north during the time you made your observations?
Answer:
It is travelling towards north.

c) Do you think that is the reason for the change in the length of the shadow of the stick day by day in activity 1 ?
Answer:
Yes, that is the reason.

d) Assuming that you did not have any calendar and knowledge of months and seasons, can you use movement of the sun to predict the arrival of winter or summer?
Answer:
Yes, if it is moving towards north, the coming season is summer (in the above case it is summer) and if it is moving towards south, the coming season is winter.

Activity – 3

Question 3.
Make your own sundial.
Answer:
First of all, you will need to cut a right angled triangle ABC from a sheet of cardboard. Angle C of the triangle should equal to the latitude of your city or town and angle A should be 90° as shown in figure.

A list of latitudes of districts of Andhra Pradesh is given below in table.

Fix your cardboard triangle vertically in the middle of a rectangular wooden board. Glue strips of paper along both edges of BC and the wooden board to make the triangle stand erect.
Place your board with the triangle on level ground in an open space which gets sunlight throughout the day. Base BC of the triangle should be placed in the north- south direction, with B pointing to the north.
At nine in the morning, draw a line along the shadow of side AC on the wooden board. Write the time along side the line. Draw lines of the shadow of side AC at one hour intervals (use a clock to check the time) through the day till sunset and mark the time for each line. Your sun-dial is ready.

Activity – 4

Question 4.
Observing phases of the moon.
a) Have you ever observed the movement of moon in the sky?
Answer:
Yes.

b) Does the moon appear at same point at a particular time everyday?
Answer:
Yes.

c) s the shape of the moon same on everyday?
Answer:
No, it changes.

Now note the date of the day after new moon day (amavasya), when the moon first appears in the sky.
Also note the time at night when the moon sets (goes down in the western sky). In the same way everyday locate the moon in the sky at the time of sunset or immediately after sunset.
Record the date and time of the moon set and draw a picture of the moon as you see it on that day in your notebook as shown in figure.
Continue making observations for as many nights as possible.
Observe the moon a few days before full moon day (Pournami) to a few days after it. Locate the position of moon in the sky at the time of sunset before Pournami and note the time and position of moon in the sky at that time.
After Pournami, note the time at which the moon rises (comes in the eastern sky) and also note the date. Draw pictures of the shape of the moon each of these days.

d) Can you calculate the number of hours between one moon rise and the next moon rise or the number of hours between one moon setting and the next moon setting, with help of these observations?
Answer:
It is about 24 hours and 50 minutes.

e) How many hours lapse between one sunrise to the next, or one sunset to the next?
Answer:
It is about 24 hours.

f) Is the time period same for sun and moon to appear at selected position after completing a cycle in the sky every day?
Answer:
No, they are different.

g) Does the moon appear at the same point every day during the time of the sunset?
Answer:
No.

h) What is the shape of the moon? Is it same every day?
Answer:
It is changing day by day.

i) You might have observed that the shape of the moon changes night after night. What is the name given to these changes in appearance ?
Answer:
These changes in its appearance are called the phases of the moon.

j) Can you guess why the shape of the moon changes?
Answer:
The time period taken by sun to complete a cycle in the sky and come to the selected position is almost same everyday and it is about 24 hours i.e., 1 day. Whereas moon takes about 50 minutes more than a day to complete the cycle and which results in the phases of moon.

Activity – 5

Question 5.
A Moon-shaped lemon.
Answer:
Choose a day one week after the new moon day when the moon is visible in the sky during the day time.
Take a yellow lemon or a whitewashed clay ball and pivot it on a long needle or on a spoke of bicycle. Hold it up towards the moon as shown in figure.

Ensure that you are standing in the sun¬shine when you do this activity.
Observe the shape formed by the sunlight on the surface of the lemon. Is there some similarity between the shape formed and the shape of the moon?
It forms one of the phase of moon.

Activity – 6

Question 6.
Why does the shape of the moon change ?
(Do this activity around 4p.m.)
Wrap a ball tightly with a white hand-kerchief or with a piece of white cloth.
Assume this is the moon. Hold this ball in front of your eyes in bright sunshine as shown in figure and turn around yourself slowly. Observe how the shape of the illuminated part of the ball changes.

a) Does sunlight fall on half the ball at all times while you turn around?
Answer:
Yes.

b) Is the shape of the illuminated part on the ball viewed by you same in all positions during your rotation?
Answer:
No, they are different.

c) Why does this happen?
Answer:
To understand this look at figure.

c) Why does this happen?
Answer:
To understand this look at figure.

The large circle in the middle of figure is the earth and the smaller circles around it represent the moon in different positions. We can see the phases of the moon on different days in the figure. The sunrays falling on the moon illuminate half its surface in all the positions. However, we cannot see the entire illuminated surface in all the positions. In some cases we see the entire illuminated surface while in others we see only part of it. In one particular position, we cannot see the illuminated surface at all.
The shape of the moon we see is the shape of the illuminated portion visible to us.
In figure, the day of the new moon is called day 0 or day 28 (position 1). In this position, the illuminated surface is not visible from earth, so the moon cannot be seen from earth.
Four days later, when the moon is in position 2, a small part of its illuminated surface is not visible from earth. On day-7, the moon is in position 3, so more of its illuminated part is visible from earth.
After fourteen days (at position 5) the entire illuminated surface of the moon is visible from earth. This is the day of the full moon.
Subsequently, the moon appears smaller with each day as it passes through positions 6 (day-18), 7(day-21) and 8(day- 25). After 28 days, the moon is once again in position 1.
Try to duplicate position 1 with the ball. For this, you will have to hold the ball towards the sun (between your eyesight and the sun).

d) In this position, which half of the ball is illuminated?
Answer: Although half the surface of the moon is illuminated everyday, we cannot see the moon on new moon day since the illuminated surface is on the side opposite to the point of observation on the earth. On a full moon day, the situation is reversed. The illuminated half of the moon faces the point of observation, so we see a full moon.

e) Where is the position of sun and moon on new moon day and full moon day?
Answer:
The sun and moon must be on the same side of the earth on a new moon day and they are on opposite sides of the earth on a full moon day.

f) Can you now state as to in which direction the moon will rise on a full moon day?
Answer:
The moon will rise from west on full moon day.
While we observe moon in clear sky on a full moon day, we think about the spots those are visible on the moon. In olden days people are curious about the spots. This led to creation of a lot of stories.

e) Do you know any such story?
Answer:
One popular story to account for the dark spot on the moon is that Ganesha, once filled with food, fell from his mouse and broke his stomache. Chandra laughed at this, at which Ganesha injured him by breaking off and throughing one of his tusks and cursed him.

Activity – 7

Question 7.
Observing the movement of constellations (stars).
Take a 20cm x 20cm square sheet of paper and make a 1cm diameter hole in its center. Mark a cross ( X ) on one side of the sheet of paper as shown in figure.

Hold the sheet in front of your eyes with the ‘X’ mark at the bottom and look for the pole star through the hole. Once you have located the pole star, check in which direction the Great Bear and Cassiopeia lie.
Write ‘G’ for Great Bear and ‘C’ for Cassiopeia on the paper in the directions in which you see each of the constellations. Mark the timing at which you made your observation in both cases.
Choose a nearby tree or house as a reference point. Draw a picture of your reference point on the paper sheet taken, clearly indicating its location. Repeat your observations at one hour intervals. Ensure that you are standing on the same spot each time you look at the stars.
Write G, C in the direction of the position of the great bear and Cassiopeia during each observation and note the time of the observation next to the letters G and C.
Using the tree or house you have chosen as your reference point, check whether the position of the pole star has changed or not. If it has changed, note the changed position.
Repeat this activity as many times as possible, the minimum being four times. But ensure that the ‘X! mark on your sheet of paper remains at the bottom during all your observations.

a) Do the positions of the stars change with time?
Answer:
Yes, they will change.

b) Does the position of the pole star also change with time?
Answer:
No, it will not change with time.

c) Does the shape of the great bear and Cassiopeia change with time or does the position of the entire constellations in the sky change?
Answer:
The position of entire constellation changes.

d) What kind of path do these constellations trace in the sky?
Answer:
They traced in northern sky.

Activity – 8

Question 8.
Why does the pole star appears fixed at one point?
Take an umbrella and open it. Make about 10-15 stars out of white paper. Paste one star at the position of the central rod of the umbrella and others at different places on the cloth near the end of each spoke.

Now rotate the umbrella by holding its central rod in your hand. Observe the stars on the umbrella.
a) Is there any star which does not appear moving? Where is this star located? Is it located where the rod of the umbrella holds the cloth of the umbrella?
Answer:
Yes, it is located where the rod of the umbrella holds the cloth of the umbrella.

b) On similar lines, if there were a star located where the axis of rotation of the earth meets the sky, could this star is also be stationary?
Answer:
Yes, that is the reason pole star does not move even though all stars appear that they are moving because of rotation of earth.

AP State Board Syllabus AP SSC 10th Class English Textbook Solutions Chapter 3A The Journey Textbook Questions and Answers.

AP State Syllabus SSC 10th Class English Solutions Chapter 3A The Journey

10th Class English Chapter 3A The Journey Textbook Questions and Answers

Look at the picture and read the following excerpt from the diary of a 72-year-old man. Answer the questions that follow.

As I sit here alone and waiting
I gaze at people passing me by.
I try to smile and reach out to them
But no one notices; no one waits.
They look to me like I am nothing
Are they afraid to be seen saying “Hi”
to an old man like me?

Question 1.
What is the excerpt about?
Answer:
The excerpt is about an old man’s inner feelings. He feels sorry for himself. Through this excerpt, he tries to tell the readers about his pathetic condition. He feels that he is totally neglected.

Question 2.
How do people respond to the old man’s smile?
Answer:
When the old man tries to smile and reach out to others, no one notices and no one waits. They look to him like he is nothing. The old man feels that they are afraid to be seen saying “Hi” to an old man like him.

Question 3.
How should old people be treated so that they do not feel neglected?
Answer:
The old people should be treated equally. They should be respected and treated with honour. They should not be bullied or laughed at. We should share our feelings with them. We should give value to their feelings. We should obey them and try to follow their pieces of advice. If we treat the old people as mentioned above, they don’t feel neglected.

I. Answer the following questions.

Question 1.
‘After spending a leisurely Sunday at home, the very thought of returning to work on Monday is tiring.’ Do you agree? Have you ever felt so?
Answer:
Yes, 1 agree to the above statement. After spending a leisurely holiday at home, the very thought of returning to work on the next day is tiring to anyone. I have felt so many a time. I felt so after Dussehra holidays, Pongal holidays and summer vacation previously. It would be a difficult day for me going to school on the very first day after the holidays are over.

Question 2.
The last sentence of the first paragraph and the first sentence of the second paragraph appear to contradict each other. What could be the reason for the change in the decision?
Answer:
The last sentence of the first paragraph says that the author didn’t want to go but the first sentence of the second paragraph says that the author decided to go finally. Both the sentences contradict each other. At first he didn’t want to go as he had got married. He didn’t want to leave behind his newly-wed wife. But, when he remembered his increased responsibilities because of his marriage and his debts, he decided to return to work.

Question 3.
‘Why did the author get into debt? Think of some possible reasons.
Answer:
The author felt that he had got into debt after his marriage.
The possible reasons are :
i) The author might have met his marriage expenses.
ii) He spent leisurely at home for about six months without going to work.
iii) The increased expenses for the new couple.
iv) The author might have bought new furniture.
v) He might have bought a new flat.
vi) He might have bought a number of sarees for his newly-wed wife.
vii) He might have spent money carelessly.
viii) He might have given money to his old parents.

Question 4.
Why was the author reluctant to carry his own luggage? What would you do if you were in the author’s place?
Answer:
The author was reluctant to carry his own luggage as he had the feeling that if he carried the luggage, the whole world would laugh at him. He thought that his education had made him shun physical labour. In fact, the author looked for someone’s help. He felt that his guilt, shame, self-consciousness and pride might have stopped him from carrying the luggage. If I were in the author’s place, I would not do like he did. I would myself carry the luggage without looking for others’ help.

Question 5.
The author feared that the whole world would laugh at him if he carried the trunk. Was the fear imaginary or real? Give reasons for your answer.
Answer:
The author feared that the whole world would laugh at him if he carried the trunk. I think his fear was imaginary. No one laughs at us when we do our work. In fact, carrying the trunk should not have been such a worry for him. For a young man like the author it should not have been an issue to carry his luggage on his back. Actually the others will praise his modesty, if he carries his luggage himself.

Question 6.
Choose one sentence from the story that best expresses the author’s false prestige. Support your answer with details from the story.
Answer:
“Somehow, I had the feeling that if 1 carried the luggage, my father and my people, in fact the whole world would laugh at me and I would be belittled,” – this sentence expresses the author’s false prestige. He thought that his education had made him avoid physical labour. As a government officer, he didn’t accept the idea of people seeing him carry his own luggage. He was of the opinion that it was through him that his parents had earned a greater degree of admiration and respect from the villagers. He felt that his father would not like to see him carrying a trunk on his back and would be very hurt if he did so. These are all the facts which show the author’s false prestige.

Question 7.
What does the phrase ‘opposite directions’ in the last sentence suggest?
Answer:
When the bus started moving, the author saw his father gradually receding into the distance. The author felt that their journeys started in two opposite directions, with him seated in the luxurious seat of a bus and father walking back with tired legs on the pebble-strewn road. The phrase ‘opposite directions’ suggests that both their directions were different. Actually, the son and the father had to travel in opposite directions to reach their destinations. In the other sense, the writer’s way was a luxurious one as he was an educated one and a government officer. He didn’t need to lead such a hard and laborious life like his father used to lead. When compared with his life, his father’s life was much harder one.

Question 8.
How was the story told? Were the events narrated in the order in which they had happened? Spot the sentences where the course of narration changed its direc¬tions. How effective was it?
Answer:
‘The Journey’ is a beautiful narrative by Yeshe Dorjee Thongchi. Most of the events were narrated in the order in which they had happened. Here and there we find that the narration changed its directions.
The sentences where the course of narration changed its directions:
a) “I did not have much to carry byway of luggage – just a trunk. Ours is a hilly terrain
Here the author tried to give the reason. Then he explained the purpose of his coming to his place. Thus, the course of narration was changed.
b) “Nobody had time to spare for me. In fact, carrying the trunk should not have been such a worry”
The course of narration was changed after the first sentence when the author tried to tell us about his inner feelings.
c) “We were walking up a narrow hilly road and neither of us uttered a word as if we were strangers who spoke different languages. I did not know what was going on in his mind.”
When we observe the two sentences given above, the first one changed its direc¬tion when the author tried to present his thoughts.
d) “Father wanted to say something but the bus started moving.” Later the narrative was changed its course when the author tried to think about his way in comparison with his father’s.
A reader could understand very well about the author’s inner thoughts by this way of narration. He too would try to think in his own way imagining that if he were in the author’s place. Thus it was effective in provoking the thoughts.

II. Write the number of the paragraph that gives the stated information in each of the following sentences.

1. The author enjoyed his married life.
Answer:
Paragraph 1 (The first paragraph)

2. The author tried to convince himself that he had not done anything wrong.
Answer:
Paragraph 11.

3. The author was ashamed of making his father carry his trunk.
Answer:
Paragraph 10.

4. The author looks at himself and his father as two travellers taking two different roads.
Answer:
Paragraph 16 (The last paragraph).

III. The following statements are false. Correct them.

1. The author offered to carry the trunk for some time.
2. The author could decide on whether to allow his father to carry the trunk or not.
3. The author took unpaid leave.
4. The father was not happy with the old shoes his son gave him.
Answer:
Corrections:

1. The author didn’t carry the trunk at all throughout the story. His father carried it all the way.
2. The author decided that it would be better to let his father carry the trunk.
3. The author initially thought of taking unpaid leave but later he decided against it.
4. The father was happy with the old shoes his son gave him. His face lit up with content-ment when he noticed the author taking out his pair of shoes from the trunk.

Vocabulary

I. Look at these words from the story :

1. newly-wed wife
2. bus stop
3. forehead

They are all compound words. A compound word is a union of two or more words to convey a unit idea or special meaning that is not as clearly or quickly conveyed by separated words. As shown above, compound words may be hyphenated, written open (as separate words), or written solid (closed). The use of compounding in English is an evolving process. As expressions become more popular or adopt special meanings, they follow a gradual evolution from two or more separate or hyphenated words to single words.

audio visual	audio-visual	audiovisual
copy editor	copy-editor	copyeditor
wild life	wild-life	wildlife

The words in the first, second and third columns are called ‘open compounds’, ‘hyphenated compounds’ and ‘closed compounds’ respectively. In this unit we focus on hyphenated compounds.

A hyphenated compound is a combination of words joined by a hyphen or hyphens. Here, the hyphen aids understanding and readability and ensures correct pronunciation. Words are hyphenated mainly to express the idea of a unit and to avoid ambiguity.

A. Pick out all the compound words from the story and group them under the head-ings as explained above.

Open compounds	Hyphenated compounds	Closed compounds
1. bus stop	1. newly-wed	1. anyone
2. government officer	2. far-off	2. someone
3. tea shop	3. 20-kilo	3. forehead
4. each other	4. home-made	4. moreover
5. bare feet	5. matter-of-fact	5. myself
	6. self-consciousness	6. anyway
	7. white-collar	7. childhood
	8. pebble-strewn	8. useless
		9. anything
		10. somehow

B. Fill in the blanks to make hyphenated compound words. Refer to a dictionary and get the meaning. Write a few sentences using them appropriately.

1.	20	kilo	chest
		rupee	note
		inch cake	tin
2.	newly	wedded	wife
		formed	association
		constructed	building
		discovered	particle
3.	flood	hit	area
	home	made	wine
	flood	hit	villages
	pebble	strewn	road
	kind	hearted	people
	well	mannered	man
4.	white	collar	job
	pink	card	holder
	new	tradp	union

Own Sentences:
1. a) He can easily lift a 20-kilo chest.
b) My father gave me a 20-rupee note.
c) We ordered a 20-inch cake tin and it has just been delivered.

2. a) Mr. Prakash came to his native place along with his newly-wedded wife.
b) The newly-formed association held an important meeting yesterday.
c) Theirs is a newly-constructed building.
d) The scientists declared that it was a newly-discovered particle-
e) The CM has visited the flood-hit area.

3. a) They served the home-made wine in the party.
b) The officials listed out the flood-hit villages.
c) I have to walk over pebble-strewn road to reach the temple.
d) They are kind-hearted people; they have made their contribution in building this hospital.
e) Mr. Rajan is a well-mannered man; he always tries to be friendly with others.

4. a) Mr. Ravi Teja was offered a white-collar job.
b) Mr. Bharat is a pink-card holder, who is eligible to take all the fair-price goods.
c) Yesterday, they formed a new-trade union.

C. Fill in the blanks with the missing parts of compound words.

Kedarnath lived in Uttarakhand. Due to heavy rains, his village was hit by floods. His newly ____(1) ____ house fell down and he became ______(2)_____ less. The Chief Minister visited all the _____ (3) ____ hit villages and announced immediate help. However, Kedarnath lost his self ____(4) ____ and tried to commit suicide by jumping into the flooded river. Some brave and ____(5) ____ hearted people rescued him risking their lives. They told their stories too. Someone had lost his ____(6) ____ wedded wife, and someone else had lost all his family members. One of them offered him a ____(7) ____ collar job. It required him to carry rice bags. But he could not carry even a 20 ____(8) ____ bag, so he asked for a ____(9) ____ job. But no such jobs were available. One of them suggested ____(10) ____ employment scheme. But Kedarnath had no money. One day as he was walking on the pebble ____(11) ____ road, he found some ____(12) ____ plated idols and jewellery in a box.
Answer:

1. built (newly-built)
2. home (homeless)
3. flood (flood-hit)
4. confidence (self-confidence)
5. kind (kind-hearted)
6. newly (newly-wedded)
7. blue (blue-collar)
8. kilo (20-kilo)
9. white-collar
10. self (self-employment)
11. strewn (pebble-strewn)
12. gold (gold-plated)

II. Look at the word ‘dilly-dally from the text. This is a reduplicative word. The words super-duper and bye bye are also reduplicative words. But they belong to different categories shown below:
1. Duplicative type :
Here, the first part of the word is repeated without any change.
e.g.: bye bye

2. Alliterative type :
Here, the two parts have the same consonants but different vowels.
e.g. : dilly-dally, chit-chat

3. Rhyming type :
Here, the second word starts with a different consonant but rhymes with the first part.
e.g. : super-duper

A. Look at the following reduplicatives carefully and put them under proper headings in the table given below.

Answer:

Duplicative	Alliterative	Rhyming
aye-aye	ding-dong	bow-wow
chuk-chuk	ping-pong	easy-peasy
bang-bang	zig-zag	okey-dokey
chop-chop	see-saw	hodge-podge
tata	hip-hop	helter-skelter
papa	chit-chat	itsy-bitsy
ha ha	pitter-patter	nitty-gritty
boo-boo	tip-top	hanky-panky
hush-hush	tick-tock	teeny-weeny
night-night	mish-mash	hurly-burly

Reduplicatives are used in a variety of ways. Some simply imitate sounds: ding- dong, bow-wow. Some suggest alternative movements: flip-flop, ping-pong. And some intensify meaning: teeny-weeny(very small), tip-top(very good).

Find the meanings of the words you like and use them in your own sentences. You will find similar words in your language too. For example, in Telugu, we have words like chi-chi, pho-pho, kaadu-kaadu, tara-tama, taado-pedo, pilla-jella, auto-ito. Give some examples from your language. Don’t they sound musical?

Reduplicative Words in Telugu

B. Answer each of the following questions using a reduplicative word.

1. What does the clock say? ____________________
2. What does the school bell say? ____________________
3. How does the rain drop? ____________________
4. What does the dog say? ____________________
5. How do you laugh? ____________________
Answer:

1. tick-tock
2. ding-dong
3. pitter-patter
4. bow-wow
5. ha ha

Grammar

I. In this story the author used past perfect tense (had + past participle) in many sentences. If you observe the following sentences from the story and the rules given under them, you will understand why and how the past perfect tense is used.’

1. It was 10.20 My father had already left, (para 6)
Answer:
When an action takes place before a point of time in the past, the action is expressed in the past perfect tense. (Sometimes the point of time can be understood from the earlier sentences and other contextual clues.)

2. Finally we reached Dirang. The bus from Tawang had not yet reached Dirang. (para 11)
Answer:
When two actions in the past are clearly separated by time, the earlier action is expressed in the past perfect tense.

3. I quickly sat down on a rock. My father laughed at my plight, (para 7)
Answer:
When two actions in the past happen simultaneously, both of them are expressed in the past tense.

4. a) Sunitha never saw a bear before she was transferred to Maredumilli. (not from the story)
b) Shindh closed the doors because she heard loud noises from outside.
c) I never met him after I left India.
Answer:
Normally, when the time relation is unambiguous, (by the use of before, after, because, etc.), the simple past (past perfect is optional) is used to refer to both past actions.

Comment on the use of the simple past tense/past perfect tense (as illustrated above) in the following sentences. Identify the tense and give reasons for the use of the tense used.

1. I had come home this time round for a special purpose: to get married. My parents had arranged my marriage according to the customs of our tribal society.
Answer:
In both the sentences, the part perfect tense is used as those two actions had already completed before his narration, (had come, had arranged)

2. Time flew, and five months into my marriage I realized it.
Answer:
In the above sentence both the verbs are in the simple past tense as the time relation is unambiguous and those two occur in the past simultaneously.

3. But after some dilly-dallying I finally decided against it because marriage had increased my responsibilities and I had got into debt.
Answer:
“Marriage had increased my responsibilities and 1 had got into debt.” – These two actions occurred before “I finally decided against it.” Hence, in the earlier two actions the past perfect tense is used while the simple past tense is used in the latter.

4. On my way home from the bus stop my trunk had been carried by a porter, (para 3)
Answer:
The above action occurred before his narrating the story. Hence, the past perfect tense (had been carried) is used.

5. A large crowd gathered at our place the day I was to leave. People had come to wish me luck, (para 6)
Answer:
A large crowd gathered at our place the day I was to leave. → In this sentence the simple past tense is used as it occurred later.

People had come to wish me luck. → In this sentence the past perfect tense is used as it occurred earlier.

People had come and then the large crowd gathered. Hence, the two tenses are used.

6. Father was quiet for some time. He thoughtfully looked at the sun for a moment, and then his eyes fell on the can of home-made wine that I was carrying, (para 9)
Answer:
The actions in the above sentences occurred in the past simultaneously. Hence, the simple past tense is used in all the actions except the last part of the second sentence. ” ……….. that I was carrying.” Here the past continuous tense is used as it was going on at the time of narrating.

7. I gave him the can of wine. He poured himself a mug and handed me the can. He drank all of it at one go. He then arranged the belt that was attached to the trunk carefully on his forehead. (para 10)
Answer:
All the actions are in the simple past tense as they all occurred in the past simultaneously and also the time relation is unambiguous.

8. I had never got used to physical labour having stayed in hostels right from my childhood. (para 11)
Answer:
“I had never get used to …………”
Here the past perfect tense is used as the author while narrating, went intq the past and told. Hence, the past perfect tense is used.

9. His feet had developed cracks and somehow resembled those of an elephant. (para 14)
Answer:
When two actions in the past are clearly separated by time, the earlier action is expressed in the past perfect tense. “His feet had developed cracks” …. This action took place before “his feet resembled those of an elephant.” Hence, the earlier action is expressed in the past perfect tense and the latter is expressed in the simple past, (had developed, resembled)

10. I noticed this for the first time. 1 hadn’t noticed that the road was uneven, (para 14)
Answer:
“I noticed this for the first time.”
Here the simple past tense is used as it is the author’s narration.
“I hadn’t noticed that …….. ”
This action might have occurred if the author did it but this action didn’t take place. Hence, the past perfect tense (+ not) is used.
” the road was uneven.” The condition of the road was mentioned here. It was
the condition of the road when he narrated. Hence, the simple past tense is used.

11. I checked my wallet and saw I still had around Rs.40 with me. (para 14)
Answer:
Both the actions in the above sentences occurred in the past simultaneously. Hence, the simple past tense is used in both the contexts.

12. I then took out my pair of leather shoes from the trunk, and noticed my father’s face lighting up with contentment, (para 15)
Answer:
The above two actions occurred in the past simultaneously and the time relation is unambiguous. Hence, the simple past tense is used, (took, noticed)

13. I saw that the road we had come by looked like a giant motionless rope, (para 16)
Answer:
“I saw that ” — Here the past tense is used to refer to the past action as it is the writer’s narration.
” ………… we had come by looked …………”
— Here the past perfect tense is used as this action had completed before his narration.
” …………… looked like a giant motion rope.” — Here the simple past tense is used to refer to the action as it is the writer’s narration.

14. He stopped his business after he became old.
Answer:
In this sentence both the verbs ‘stopped’ and ‘became’ are in the past tense as the time is unambiguous.

15. I never ate ‘haleem’ before I visited Hyderabad.
Answer:
In this sentence the verbs ’ate’ and ‘visited’ are in the past tense as the time is unambiguous.

II. Adverbial Clauses

Study the following examples from the story.
1. As I had to do a bit of catching up, I walked fast.
2. As I was going to take my first sip. 1 heard father’s voice.
3. He decided to go to his work place because he got into debts.

In all the above sentences there are two clauses. The underlined part is the adverbial clause.
There are several types of adverbial clauses.

Combine the pairs of sentences by using the words given in brackets.
1. There was nobody in the village to carry the author’s luggage. Everbody was engaged in some important work, (because)
2. The roads were not good. He preferred less luggage, (as)
3. He wanted to stay at home for some more days. He wanted to apply for leave, (since)
4. You may not attend the class. You don’t want to come again, (if)
5. The boy was about to come down the stairs. Then it crumbled down, (when)
Answer:

1. There was nobody in the village to carry the author’s luggage because everybody was engaged in some important work.
2. As the roads were not good, he preferred less luggage.
3. Since he wanted to stay at home for some more days, he wanted to apply for leave.
4. If you want to come again, you have to attend the class.
5. Whan the boy was about to come down the stairs, it crumbled down.

More about Adverbial Clauses :

1. Adverbial Clauses of Time :
Adverbial Clauses of Time are introduced by the subordinating conjunctions when-ever, since, after, before, while, as, etc.
e.d.:
1) As Bayaji came home, his children returned.
2) As soon as the bell rang, the children came out crying.
3) While Sachin was batting, there was a heavy noise all over the stadium.

2. Adverbial Clauses of Place :
Adverbial Clauses of Place are introduced by the subordinating conjunctions where and whereas.
e.g.:
1) You can go wherever you like.
2) I want to live where you live.

3. Adverbial Clauses of Reason :
Adverbial Clauses of Reason are introduced by the subordinating conjunctions because, that, as, since.
e.g.:
1) Because he was ill, he didn’t come.
2) He was very happy that his son had passed.
3) As she was absent from school, the teacher punished her.

4. Adverbial Clauses of Manner :
Adverbial Clauses of Manner are introduced by the subordinating conjunctions like, as, as if.
e.g.:
1) He finished the work as she requested.
2) He is acting like he doesn’t like her.
3) They talked as if they had read.

5. Adverbial Clauses of Purpose :
Adverbial Clauses of Purpose are introduced by the subordinating conjunctions so that, in order that and lest
e.g.:
1) Work hard lest you should fail.
2) We eat so that we may live.
3) Sunlight is needed in order that the process of photosynthesis takes place.

6. Adverbial Clauses of Condition :
Adverbial Clauses of Condition are introduced by the subordinating conjunctions if, whether, unless.
e.g.:
1) Unless you work harder, you will fail.
2) If I go to Hyderabad, I will meet your brother.
3) She was uncertain whether to stay or leave.

7. Adverbial Clauses of Consequence :
Adverbial Clauses of Consequence are introduced by the subordinating conjunction that.
e.g.:
1) She is such a kind man that all love him.
2) She speaks in such a low voice that nobody can hear her.

8. Adverbial Clauses of Comparison :
Adverbial Clauses of Comparison of Degree are introduced by the subordinating conjunction than, or by the Relative Adverb as …. as.
e.g.:
1) She is younger than he.
2) He is as stupid as he is lazy.

9. Adverbial Clauses of Concession :
Adverbial Clauses of Concession are introduced by the subordinating conjunctions though, although, even if.
e.g.:
1) Though he is poor he is honest.
2) Even if it rains 1 shall come.
3) He passed in first division although he didn’t work hard.

Writing

I. In the story ‘The Journey’ the author says “…. my education had made me shun physical labour”. This is an adverse effect of education. Now write an essay on ‘The Adverse Effects of Education’. Here are some points:
Effect on
• doing some work that involves physical labour
• dress/fashion
• family relationships
• giving respect to elders
• the treatment of illiterate people
Answer:

The Adverse Effects of Education

It is a well-known fact that education plays a vital role in bringing up both economically and socially. It is thought that education helps people in so many ways. Highly educated people are enjoying the status in the present day society. People with high education attain a good job, more money and many other benefits. A literate person can show the right path to others. We usually think of the benefits of education only but we should not ignore the adverse effects of education.

When the pupils spend all their time in reading and writing, there is no scope for them to do any other work. They don’t find time even to play games. Their education makes them physically weak. They are unable to do any work that involves physical labour. “A sound mind in a sound body” is a proverb. Both the sound mind and the sound body are needed if one desires to be successful. When we are helathy, we can perform our functions regularly and properly. Today, most of the pupils stay in hostels right from their childhood. Hence, they never get the chance to do physical labour. One’s physical labour will make oneself both physically and mentally strong. But today’s education system doesn’t allow the pupils to do physical labour. And the other thing is that the educated people think that others will laugh at them if they do any kind of physical labour. They think that theirs is an important position in the society. Doing their own things is the point of prestige for them. Their false prestige makes them think in a wrong way.

The second point is their dress sense. The persons with high education try to wear fashionable dresses which are different from other ones. As far as the educated Indians are concerned, they give more value to the western culture. They try to adapt the foreigners’ culture. They never think of our culture and traditions. They think that only illiterate people wear such kind of dresses which reflect our culture. In their view, they will be degraded if they don’t wear modern dresses. This thought only leads to other social problems. The young women’s dress sense will cause them a threat. They think that they are superior to the uneducated ones and behave arrogantly.

Another important point is how education affects the family relations. When a person completes his education, he starts thinking that he is greater than the other uneducated members of his family. He wants to show his dominance. If he gets employment, he doesn’t find time to spend with them. He always thinks about earning money. He gives importance to money only. He doesn’t show any love and affection even for his parents. Thus, one’s education leads to the absence of human relationships.

Most of the literates don’t give any respect to elders. As Indians, we generally have faith in our values, traditions and culture. What we have learnt from our ancestors is that we should give utmost respect to our elders. At present, we witness a different scenario. Some educated persons think that there is no use of elders. They forget the sacrifices made by them. They ill-treat their family members who are illiterates. This will lead to the destruction of family relationships.

No doubt, there are so many advantages with the education one gets. But one’s education makes one senseless. The educated persons must not move away from physical labour. They must do some work that involves physical labour. They should take care about their dress. They should not deviate from our traditional way of dressing. They should maintain good family relationships. They should respect elders. They should treat the illiterate people with courtesy. Then only their education is meaningful.

II. Summarising

A few guidelines and tips to summarize a text are given below. Read them carefully. Then read the essay ‘On Umbrella Morals’ and summarize it.

Guidelines and tips to summarize a text

To summarize is to condense a text to its main points and to do so in your own words. To include every detail is neither necessary nor desirable. In order to write a good summary, you may have to gather minor points or components of an argument from different places in the text in order to summarize the text in an organized way. A point made in the beginning of an essay and then one made toward the end may need to be grouped together in your summary to concisely convey the argument that the author is making.

Here are a few key points:

1. Read the article carefully – as many times as you require!
2. Begin your summary by mentioning the author and title. The publication and date may also be mentioned.
3. Summarize in your own words in third person using simple present tense.
4. Use transition words (however, moreover, then, also, etc.).
5. Avoid unnecessary details and direct quotes.
6. Do not give your own opinion.
7. Keep it within the word limit given or one third of the original text.
8. Prefer short and simple sentences.
9. Be consistent with the tense.
10. Check for grammar and punctuation errors.

Read the following essay.

On Umbrella Morals

-Alfred George Gardiner

A sharp shower came on as I walked along the street, but 1 did not put up my umbrella. The truth is I couldn’t put up my umbrella. The frame would not work for one thing, and even if it had worked, I would not have put the thing up, because it was falling to pieces and I would be the laughing stock. The fact is, the umbrella is not my umbrella at all. It is the umbrella of some person who I hope will read these lines: He has got my silk umbrella. I have got the cotton one he left in exchange. I imagine him walking along the street under my umbrella, and throwing a scornful glance at the fellow who was carrying his ugly thing. I dare say the rascal laughed silently as he eyed the fool with his cotton umbrella. He is one of those people who have what I may call an umbrella conscience.

I hope you know the sort of person I mean. He would never put his hand in another’s pocket, or forge a cheque or rob a cashbox —not even if he had the chance. But he will swap umbrellas, or forget to return a book, or take a rise out of the railway company. In fact he is a thoroughly honest man who allows his honesty the benefit of the doubt. Perhaps he takes your umbrella at random from the barber’s stand. He knows he can’t get a worse one than his own. He may get a better one. He doesn’t look at it very closely until he is well on his way. Then, “Dear me! I’ve taken the wrong umbrella,” he says, with an air of surprise, for he likes really to feel that he has made a mistake. “Ah, well, it’s no use going back now. He’d be gone. And I’ve left him mine! “It is thus that we play hide-and-seek with our own conscience. It is not enough not to be found out by others; we refuse to be found out by ourselves. Quite impeccable people, people who ordinarily seem unspotted from the world, are afflicted with umbrella morals.

It was a well-known preacher who was found dead in a first-class railway carriage with a third-class ticket in his pocket. And as for books, who has any morals where they are concerned? I remember some years ago the library of a famous divine and literary critic, who had died, being old. It was a splendid library of rare books, chiefly concerned with seventeenth-century writers, about whom he was a distinguished authority. Multitudes of the books had the marks of libraries all over the country. He had borrowed them and never found a convenient opportunity of returning them. They clung to him like pre-cedents to law. Yet he was a holy man and preached admirable sermons, as I can bear witness. And, if you press me on the point, I shall have to own that it is hard to part with a book you have come to love.

It is possible, of course, that the gentleman who took my silk umbrella did really make a mistake. Perhaps if he knew the owner, he would return it with his compliments. After my experience to-day, I think I will engrave my name on my umbrella. But not on that baggy thing standing in the corner. I do not care who relieves me of that. It is anybody’s for the taking.

Study Skills

Use the following graphic organizers to represent your understanding of the story ‘The Journey’. Modify the layout to suit your needs.

i) 1. How could I allow my old father to carry my trunk?
2. What would people think?
3. What would they say?
4. It was improper for me to let father carry the luggage.
5. It was through me that they (my parents) had earned a greater degree of admiration and respect from the villagers.
6. He was stronger and more skilled than I in these matters.

ii) 1. His education had made him shun physical labour.
2. His father, his people, and the whole world would laugh at him and he would be belittled.
3. His father would not like him to see him carrying a trunk on his back.

iii) I would myself carry my luggage. I wouldn’t make my father carry it.
iv) The author’s action is inhuman. He is thankless and selfish.
v) The author is ungrateful. He doesn’t show any respect, love, and affection for his father.

Listening

Listen to the story and answer the questions that follow.

Once there was a very rich man. His name was Dhanaraju. He had two sons, Ganiraju and Pothuraju. Ganiraju was hard working and obedient. He always helped his father in the fields. But Pothuraju was lazy. He never went to fields. He was disobedient to his father. He always wanted to lead a free, lavish life, so one day he said to his father, “Father, give me my share of property.” The father was heart-broken. He divided the property between his two sons. Pothuraju left home with his share. He went to a distant land, made a lot of friends and soon spent all his property lavishly on friends, food and drinks. All his friends left him.

At that time, there was a famine and Pothuraju had no work and food. None of his friends gave him food or money. He took up the job of feeding pigs. Sometimes, he had to eat the food kept for the pigs. He was very sad about his condition. He soon began to think of his father and his brother. He said to himself, “In my father’s house, even the servants have enough food. They get good shelter too. But here, I am struggling for food and shelter. I will go back to my father. 1 will beg him to take me as his servant.”
So decided, the dishonest son set out for his father’s house. In the meantime, his father was always thinking of his second son. He would sit near the windows. He would look out at the road, expecting his son to return home.

One day Dhanaraju saw his son coming at a distance. He rah out of the house in great joy and hugged his son. His son knelt down. He said, “Father, 1 am not fit to be your son. Take me as your servant.”

I. Read the statements given below and mark True or False against each of them.

1. Pothuraju went to far-off lands to enjoy free life.
2. Ganiraju asked his father to give his share of property.
3. Pothuraju had a lavish life from the beginning.
4. Dhanaraju did not care about Pothuraju.
Answer:
1. True
2. False
3. False
4. False

II. Which of the following is the most appropriate title for the story you have just listened to?
a) A Rich Son
b) Repentance
c) Two Sons
Answer:
(b) Repentance

The Journey Summary in English

The Journey’ is an excellent piece of work written by Yeshe Dorjee Thongchi, a prominent Assamese writer and it is translated into English by D.P. Nath. The author was a government officer. He came to his village to get married. His parents had arranged his marriage, according to the customs of their tribal society. After spending six months at home, he was preparing to return to his place of work. But he didn’t want to leave behind his newly-wed wife. He thought of extending his leave too. But his responsibilities made him decide to go.

As theirs is a hilly terrain, without any motorable roads, the author always prefers to carry less luggage. Now, his problem was that he needed someone to carry his luggage as his education had made him avoid physical labour. Since most of the villagers were busy in the fields, he couldn’t find even one who could help him carry the trunk to the bus stop. Finally, the writer’s father told him that he would see him off at Dirang. He didn’t want to allow his old father to carry his trunk and so he protested. But his father decided to carry the chest to the bus stop. On the day of his departure, a large crowd gathered to wish him luck and the author left for Dirang at 10 : 20. His father had already left and he had to walk fast to catch up his father. He was very tired when he caught up with his father. He sat on a rock to rest for a while. His father drank all the wine given by him and resumed carrying the luggage on his back. The author followed his father. Neither of them spoke a word as if they were strangers. The author thought that it was improper for him to let his father carry the luggage. Although he wanted to tell his father that he would like to carry the trunk himself, he couldn’t do so because of his guilt, shame and pride. He felt that the whole world would laugh at him if he did so.

The author knew that his father had provided for his education. He thought that it was through him that his parents had earned admiration and respect from the villagers. He knew that he was physically useless in spite of his youth and strength. He concluded that it would be better to let his father carry the luggage and followed him silently After resting at two places for tiffin, they reached Dirang finally. They entered a tea shop and started sipping tea. His father asked him if he had a pair of old shoes. Then the author looked at his father’s bare feet and noticed that they were full of cracks. He noticed this for the first time. He offered his father money but he refused to take. Instead, he wanted the author’s old pair. So, the author gave him the hunting boots he was wearing. His father filled with satisfaction when he saw the author taking out his pair of leather shoes from the trunk. His father wanted to say something to him but the bus started moving. Finally the author realized that both their ways were different – his way was a luxurious one while his father’s was a difficult one.

The Journey Glossary

lethargy (n) : the state of not having any energy or enthusiasm for doing things
creeps (v) : develops very slowly
terrain (n) : a particular type of land
extend (v) : to continue for a longer period of time
dilly-dallying (v) : taking a long time to do something, go somewhere or make a decision
debt (n) : a sum of money that a person or organization owes
shun (v) : to avoid something or somebody
chest (n) : a large strong box
see off (phr.v.) : to go to an airport, station, etc. to say goodbye to someone
protest (v) : to say that one strongly disagrees with
dissuade (v) : to convince somebody not to do something
catch up (phr.v.) : to come from behind and reach someone in front of you by going faster
plight (n) : a difficult and sad situation
utter (v) : to say something
guilt (n) : the unhappy feelings caused by knowing that you have done something wrong
self-consciousness (n) : feelings of nervousness about what other people think of you
belittle (v) : to make someone or something seem small or unimportant
hardly (adv) : almost not
sip (n) : a very small amount of a drink
pebbles (n) : small smooth stones
bare feet (n.phrase) : the feet without chappals or shoes
contentment (n) : a feeling of happiness or satisfaction
recede (v) : move back from a previous position further and further until it disappears
weary (adj) : very tired
pebble-strewn road (n.phrase) : the road over which pebbles are scattered

AP State Syllabus AP Board 8th Class Physical Science Solutions Chapter 10 Reflection of Light at Plane Surfaces Textbook Questions and Answers.

AP State Syllabus 8th Class Physical Science Solutions 10th Lesson Reflection of Light at Plane Surfaces

8th Class Physical Science 10th Lesson Reflection of Light at Plane Surfaces Textbook Questions and Answers

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Question 1.
State the laws of reflection of light (OR)
Name the laws of reflection of light
Answer:
Laws of reflection:

1. When light gets reflected from a surface, the angle of reflection is equal to the angle of incidence, i.e., ∠i = ∠r.
   
2. The incident ray, the normal at the point of incidence and the reflected ray lie in the same plane, i.e., AO, ON, OB are in same plane.

Question 2.
How do you verify the 1st law of reflection of light with an experiment?
(OR)
Raghu found that for a plane mirror angle of incidence is equal to the angle of reflection. Write the experiment to prove this fact. (OR)
Prove: ∠i = ∠r (LAB ACTIVITY – 1)
Answer:
Aim: Verification of first law of reflection.
Required materials: Mirror strip, drawing board, white paper, pins, clamps, scale and pencil.
Procedure:

1. Take a drawing board and fix a white paper on it with the help of clamps.
2. Draw a straight line AB at the centre of the paper and also a normal (ON) to AB at the point ‘O’.
3. Draw a straight line PQ making certain angle (angle i) with ON.
4. Fix two pins at P and Q on the paper vertically.
   
5. Observe the images of pins – P’ of the pin P and Q’ of the pin Q, in the mirror kept along the line segment AB.
6. Fix two more pins R and S such that they are in the same line as that of P’ and Q’.
7. Join R, S and 0 as shown in figure.
8. Measure the angle between RS and ON (angle of reflection).
9. We will find that ∠i = ∠r. (angle of incidence = angle of reflection)
10. Repeat the experiment with different angles of incidence and measure the corresponding angles of reflection.
11. We can find angle of incidence = angle of reflection in all these cases.
    Thus first law of reflection is proved.

Question 3.
How do you verify the 2nd law of reflection of light with an experiment?
(OR)
John found that incident ray, reflected ray and normal drawn to surface lie on the
same plane. What are the apparatus required for this experiment? How are you able to prove this fact experimentally?
Answer:
2nd Law of reflection: The incident ray, the reflected ray and normal all lie in the same plane.

1. As shown in the figure, a light ray incident on a plane mirror and touches at a point ‘O’. Here AO is called incident ray.
2. When a ray of light falls on a mirror, the mirror sends it back in another direction OB. Here OB is called reflected ray.
3. Normal is a line which is perpendicular to the mirror at the point of incidence. So the line ON’ is the normal to the mirror surface at point ‘O’.
   
4. Here the incident ray (AO), the reflected ray (OB) and the normal (ON) all lie in the same plane of the paper.
   Hence 2nd law of reflection is proved.

Question 4.
Explain the image formation by pin hole camera with the help of the diagram.
(ACTIVITY – 1)
Answer:

1. Draw a ray diagram of the formation of an image in a pinhole camera.
2. Observe the flame of a candle with a pinhole camera making a big hole to it.
   
3. We can understand that the light rays coming from the top of the candle flame fall at different points on the screen.
4. Similarly, the rays coming from bottom of the candle points on the screen.
5. Thus, we get blurred image on the screen due to the big hole of the camera.

Question 5.
Find the plane of the reflection experimentally for the incident ray which passes through the heads of the pins pierced in front of the mirror.
(OR)
Sudheer wants to verify the laws of reflection. What apparatus he requires to prove them? State the laws of reflection and write the experimentation process he follows.
Answer:
Aim: Verification of laws of reflection.
Required material: Mirror strip, drawing board, white paper, pins, clamps, scale and pencil.
Procedure:

1. Take a drawing board and fix a white paper on it with the help of clamps.
2. Draw a straight line AB at the centre of the paper and also a normal (ON) to AB at the point ‘O’.
3. Draw a straight line PQ making certain angle (∠i) with ON.
4. Fix two pins at P and Q on the paper vertically.
   
5. Observe the image P’ of the pin P and Q’ of the pin Q, in the mirror kept along line segment AB.
6. Fix two more pins R and S such that they are in the same line as that of P’ and Q’.
7. Join R, S and O.
8. Measure the angle between RS and ON (∠r) .We will find ∠i = ∠r.
9. Repeat the experiment with different angles of incidence and measure the corresponding angles of reflection.
10. We find that each case angle of incidence is equal to angle of reflection. That is first law.
11. We can find that the incident ray is the ray which is passing through points P and Q touching the paper.
12. The reflected ray is the ray which is passing through the points R and S touching the same paper and ON is the normal to the mirror at O. All lie in same plane. That is second law which states incident ray, reflected ray and normal drawn to plane lie in the same plane.

Question 6.
Have you ever observed the image of the sky in rain water pools on earth? Explain the reflection of light in this context.
Answer:
Surface of the rain water pool acts as a plane mirror, because of its smooth surface. The light rays from the sky and clouds incident at this surface and reflect. Hence, the images of the sky and clouds appear in the rain water pools.

Question 7.
Discuss the merits and demerits of using mirrors in building elevation.
(OR)
What are the advantages and disadvantages of using mirrors in building elevation?
Answer:
Merits:

1. The mirrors used in elevating building are tough, reinforced and laminated glasses so they provide safety to the building.
2. They make the building attractive.
3. They absorb heat energy, so they cool inside the building.
4. If we use plane mirrors in building elevation it is easy to wash with water and no need of regular painting.

Demerits:

1. Elevation of buildings with mirrors is not suggestable.
2. These mirrors reflect sun rays at day time and reflects lighting from near by electrical bulbs at night time, which causes confusion and disturbance for the vehicles and people who are running on the nearby roads lead to accidents.
3. Birds like sparrows, crows will get confusion while flying on roads.
4. They are also not safe enough to the buildings, which causes easy access to thieves.
5. This glass elevation is not environmental friendly, because natural air does not enter into the building.
6. They are easy to break and cause cuts and wounds.

Question 8.
If a ray incidence normally on a plane mirror, what will be the angle of reflection.
Answer:
If a ray incidence normally on a plane mirror, the angle of reflection will be zero.

Question 9.
Why does the image in plane mirror suffers lateral inversion?
Answer:
The light rays which come from our right side get reflected from the plane mirror reach our eye. Our brain feels that the rays is coming from the inside of the mirror. That is why our right side looks like left side in the image. This is called right-left inversion or lateral inversion.

Question 10.
Draw a ray diagram to understand the formation of image for a pointed object by a plane mirror explain it.
Answer:
Observe the figure. ‘O’ is a point object.

Some rays from ‘O’ reach the mirror and get reflected. When we look into the mirror, the reflected rays seem to be coming from the point T. So, point I is the image of point object ‘O’.

Question 11.
In the adjacent figure, AO and OB are incident and reflected rays respectively angle ∠AOB = 90°. Find the values of angle of incidence and angle of reflection.

Answer:
We know that angle of incidence is equal to angle of reflection.
i = r …….. (1)
From the figure, ∠AOB indicates i + r = 90°
From (1)
⇒ i + i = 90°
2i = 90°
⇒ i = 90/2 = 45°
⇒ i = r = 45°
Angle of incidence i = 45°; Angle of reflection r = 45°.

Question 12.
Hinduja stands in front of a plane mirror at a distance of 5 m. from the mirror and observes her image in the mirror. If she moves 2 m. towards the plane mirror, then what will be the distance between Hinduja and his image?
Answer:
The distance between plane mirror and Hinduja = 5 m
The distance between plane mirror and Hinduja after moving 2 m towards mirror
= 5 – 2 = 3 m …….. (1)
The distance between plane mirror and Hinduja’s image after moving = 3 m …….. (2)
The distance between Hinduja and her image after moving = (1) + (2) = 3m + 3m = 6m.

Question 13.
Explain diagramatically the Image of letter ‘B’ in a plane mirror.
Answer:

Question 14.
Why can’t we see our image in a white sheet of paper though it reflects light?
Answer:
By microscopic observation, we can find up and downs over surface of a paper. Hence paper is not a smooth fine surface. Even though sheet of white paper reflects the light rays, they do not form an image of an object.

Question 15.
Observe the below figure. AB and BC are two plane mirrors arranged at 120°. A ray incidents at and angle 55° on AB. Find the value of ‘x’

Answer:
Let us say, angles a, b, c, d as shown in the figure. From the figure, a = 55° [∵ i = r]
a + b = 90° [. Normal to the plane]
55° + b = 90°
⇒ b = 90° – 55° = 35°
120° + b + c = 180° [∵ Total of angles in a triangle]
120° + 35° + c = 180°

⇒ c = 180° – 155° = 25° c + d = 90° [∵ Normal to the plane]
25° + d = 90°
⇒ d = 90° – 25° = 65°
d = x [∵ i = r]
∴ x = 65°

Question 16.
The size of the image in the mirror seem to be decreased when you move the object towards your eye from the mirror. Draw the diagram showing angles depicting the situation.
Answer:

Question 17.
Collect the information about “Situations using the plane mirrors and prepare the report.
Answer:
Plane mirrors have many uses.

1. Periscopes: They are used in periscopes to see bends and corners. It is used for observing enemy movements from trenches without any danger of being seen. Sailors on submarines use periscopes to see things above the water level.
2. Kaleidoscopes: Kaleidoscope is a toy that uses light and mirrors to reflect objects and create beautiful, fascinating repeating patterns.
3. Security: Mirrors are used while looking for explosives underneath a vehicle. Even these mirrors are used in shops to keep an eye on the customers. Mirrors are also used in blind turns of busy roads to see the vehicles coming from the other side.
4. Telescopes and Microscopes: Plane mirrors are used in many scientific applications like telescopes and microscopes.
5. Dressing mirrors: Plane mirrors are used in dressing tables to see ourselves, while dressing, shaving, etc.
6. Ophthalmic doctors: They use plane mirrors to increase the distance of the eye test chart while examine the eye of a patient.
7. Docorating mirrors: Plane mirrors are used to decorate the building for elivations. Some shops also used plane mirrors to get multiple images of the items in their shops.

MULTIPLE CHOICE QUESTIONS
1. Angle of incidence = Angle of reflection. This rule is explained by …………… principle        ( )
A) Fermat
B) Newton
C) Archemedes
D) Pascal
Answer: A

2. Which of the following letters doesn’t suffer lateral inversion?         ( )
A) C
B) O
C) B
D) N
Answer: B

3. A ray of light incidents on a plane mirror at an angle of 90° to its surface. What will be the angle of relfection?   ( )
A) 0°
B) 90°
C) 450°
D) 180°
Answer: A

4. If we move an object away from the plane mirror the size of images seems to be     ( )
A) increases
B) decreases
C) of the same size
D) image can’t be seen
Answer: B

5. Which of the following is incorrect with respect to the image in a plane mirror?     ( )
A) Image is erect
B) size of the image is same as the size of object
C) laterally inverted
D) image is real.
Answer: D

6. An object is placed 7cm distance from the plane mirror then distance of image is      ( )
A) 3.5 cm
B) 14 cm
C) 7 cm
D) 21 cm
Answer: C

8th Class Physical Science 10th Lesson Reflection of Light at Plane Surfaces InText Questions and Answers

8th Class Physical Science Textbook Page No. 134

Question 1.
How can we get the image of a big building in a small mirror?
Answer:
Light rays travel in all directions from one object. Light rays coming from a building incident on the small area of a plane mirror and reflect. These reflected rays reach our eye. We see the image of the building in the mirror.

Question 2.
Can we get the image formed by a plane mirror on a screen?
Answer:
Cannot.

Question 3.
Why is there lateral inversion, when we look into a mirror?
Answer:
Our brain feels that the rays is coming from the inside of the mirror.

Question 4.
Why is the angle of reflection equal to the angle of incidence when a light ray gets reflected from a surface?
Answer:
Light always choose the path of least time to travel.

8th Class Physical Science Textbook Page No. 138

Question 5.
Is the angle of reflection equal to the angle of incidence in all cases?
Answer:
Yes.

Question 6.
Do the two rays and the normal lie in the same plane? If yes, which is that plane?
Answer:
Yes, plane of paper.

Question 7.
In which plane will the incident ray, reflected ray and the normal lie?
Answer:
Plane touching the heads of pins and parallel to the plane of paper.

Question 8.
How will the incident ray be?
Answer:
Incident ray touching heads of the pins (P and Q) and make some angle with plane of the paper.

Question 9.
How will the reflected ray be?
Answer:
Reflected ray will make some angle with plane of the paper.

Question 10.
How will the normal be?
Answer:
The normal will also make same angle as incident and reflected rays.

Question 11.
How will the plane of reflection be?
Answer:
Plane of reflection make some angle (which is equal to plane of the paper and incident ray) with plane of the paper.

Question 12.
How does a mirror form the image of a pin or any object? Let us discuss.
Answer:
The rays coming from the pin get reflected from the mirror and seem to be coming from the image in the mirror.

8th Class Physical Science Textbook Page No. 139

Question 13.
What is the size of the image compared to the size of the object?
Answer:
Size of the image is equal to size of the object.

Question 14.
What do you say about the size of the image compared to the size of the object? Move the object towards your eye. What do you observe?
Answer:
Size of the image is same as size of the object. If we move the object towards our eye, size of the image of the object seems to be decreased.

Question 15.
Is the size of the image decreasing or increasing?
Answer:
Decreasing.

8th Class Physical Science Textbook Page No. 140

Question 16.
Why does an image suffer lateral (right-left) inversion? See the figure.

Answer:
Our brain feels that the rays are coming from the inside of the mirror and image is opposite to us. In this way image suffer lateral inversion.

Question 17.
What do you understand from the figure?
Answer:
The light rays which come from our right ear get reflected from the plane mirror and reach our eye. Our brain feels that the ray is coming from the inside of the mirror. That is why our right ear looks like left ear in the image.

Think, Discuss and Write

8th Class Physical Science Textbook Page No. 135

Question 1.
Does the explanation on pinhole match with your observation?
Answer:
Yes, it matches with my observation.

Question 2.
What happens if the hole Is much bigger, i.e., equal to the size of the flame?
Answer:
The image is extremely blurred.

Question 3.
If so, can we get the image of flame on the screen of pinhole camera? Why?
Answer:
No. Because the light rays coming from the top of the flame and bottom of the flame fall at different points on the screen. So it is blurred and is not formed on screen.

Question 4.
What happens if we observe the same flame with the same pinhole camera from a long distance?
Answer:
We may observe not only the flame, but the blurred image of entire candle.

Question 5.
What happens if we made two holes to pin hole camera?
Answer:
Two images will be formed.

8th Class Physical Science 10th Lesson Reflection of Light at Plane Surfaces Activities

Activity – 2

Question 1.
Which grain on the ground that a smart crow on tree A pick to reach B in short time (Shortest path)? Explain. (OR)
How do you support your answer to “When light gets reflected from a surface, it selects the path that takes the least time”? (OR)
Explain Fermat’s principle by using an activity.
Answer:

1. The crow can pick the grain from any point on the ground, but the condition is selecting the shortest path.
2. Let the speed of the crow is constants –
3. Observe some of the paths in figure.
4. To compare the lengths of these paths ACB, ADB, AEB and AFB, make the duplicates of them at point G as shown in figure.
5. In the figure CB = CG,
   ∴ The length of path ACB = AC + CB = AC + CG = ACG
6. Similarly length of the path ADB = length of the path ADG Similarlylength of the path AEB = length of the path AEG Similarly length of the path AFB = length of the path AFG
7. By observing the above paths, we will notice that AEG is the shortest path among all the paths, because it is the straight line distance between points A and G.
8. So the smart crow will pick the grain from point E.

Activity – 3

Question 2.
Look at the following figure.
Suppose if you have been given a plane mirror strip, what will you do to obtain figures as shown below figure (b) using mirror strip and the above figure (a)?

Answer:
The place of mirror that should be place on the figure vertically has been shown here under by a line.

In the above diagrams, line indicates the position of mirror to be kept to get the required shapes.

AP State Syllabus AP Board 8th Class Physical Science Solutions Chapter 9 Electrical Conductivity of Liquids Textbook Questions and Answers.

AP State Syllabus 8th Class Physical Science Solutions 9th Lesson Electrical Conductivity of Liquids

8th Class Physical Science 9th Lesson Electrical Conductivity of Liquids Textbook Questions and Answers

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Question 1.
Give examples for good solid conductors and liquid conductors.
Answer:
Examples for good conductors in solids:
Silver, copper, iron, graphite, etc.
Examples for good conductors in liquids:
Mercury, acid solutions (HCl, H₂SO₄), base solutions (NaOH, KOH), salt solutions (NaCl, KCl), etc.

Question 2.
Give examples for bad solid conductors and liquid conductors.
Answer:
Examples for poor conductors in solids:
Gold, platinum, etc.
Examples for bad conductors in liquids:
Distilled water, coconut oil, petrol, vegetable oil, kerosene, alcohol, etc.

Question 3.
What do you add to distilled water for making it to conduct electricity?
Answer:
Distilled water is poor conductor of electricity. In order to increase conductivity we should have to add either acid, base or salt. That will increase the conductivity of distilled water due to decomposition of these substances into constitute ions.

Question 4.
What is an electrolyte ?
Answer:
Electrolyte is a solution of substance through which current can pass.

Question 5.
Which energy is cause for glowing of bulb in electrolytic cell?
Answer:
Electrolytic cell is a device which converts chemical energy into electrical energy. So chemical energy stored in the cell is cause for glowing of bulb.

Question 6.
Write the uses of electroplating.
Answer:
Uses of electroplating:

1. Metals like iron are coated with deposits of nickel or chromium to prevent rusting.
2. Machinery parts are often chromium plated to protect them from corrosion and at the same time to give them good polish.
3. Electroplating is also used in repairing worn out parts of machinery.
4. Electroplating is also done for ornamentation and decoration purposes.
5. Processed food items are preserved in tin coated iron cans by electroplating method.
6. Zinc coated iron by electroplating method is used for bridges and in automobiles.

Question 7.
In case of a fire, before the fire men use the water, they shut off the main electrical supply for the area. Explain why they do this.
Answer:
Fire men use water to put out fire. Water containing dissolved salts is a good conductor of electricity. If fire men pour water on fire the electrical appliances near the fire may be wet if anybody touches those appliances they may have electric shock. In order to avoid people to get electric shock due to wet electrical appliances the fire men shut off electrical supply before they use water.

Question 8.
We get some items made from iron wire in which iron wire is coated with plastic. Is plastic coated by the process of electroplating? Why plastic cannot be coated on a metal by the process of electroplating?
Answer:
No. Plastic cannot be coated on a metal by using electroplating. The reason is plastic being a carbon polymer does not dissociate into ions. So it does not allow passage of current. So it does not act as an electrolyte. So electrolysis process is not possible with plastic which is main criteria for electroplating. So plastic cannot be coated on a metal by the process of electroplating.

Question 9.
Kavya observed that a discharged dry cell which kept in sunlight by her father for few hours got ability to glow LED. She got many doubts and questions to raise. Can you guess those questions or doubts? (OR)
Rohan observed that a discharged dry cell which kept in sunlight by his brother for few hours got ability to glow LED. He got many doubts and questions to raise. Guess the doubts or questions.
Answer:

1. Why does the bulb glow?
2. How does the dry cell charged?
3. Which energy is useful in charging the discharged dry cell?
4. Shall we use that energy to get rid from electrical power cut?

Question 10.
Explain the process of coating copper on iron key. Draw the circuit diagram.
(OR)
Conduct an experiment for coating on iron key with copper by electroplating method and prepare a note.
Lab Activity
Answer:
Aim: Coating an iron key with copper by electroplating method.
Required material: Copper plate of size 2 cm x 5 cm, crystals of copper sulphate, a key made by iron, glass beaker, water, sulphuric acid, battery cell and some connecting copper wires.
Procedure: Dissolve crystals of copper sulphate in pure water to prepare concentrated solution. Pour the solution in a beaker and add a few drops of dilute sulphuric acid to it.

Tie one end of connecting copper wire to iron object to be coated with copper. Connect other end to the negative terminal of battery. Suspend the tied iron object into the copper sulphate solution. Suspend the copper plate into copper sulphate from positive end of the battery through a switch as shown in the above figure. Key and plate are a little away from each other. Put the switch on for about 10 minutes. Switch the circuit off and take the iron key out.
We can observe a red coating on iron key. The reason is when electric current is pass through copper solution, in which copper sulphate is present in the form of copper and sulphate ions. The copper ion gets drawn to the electrode connected to the negative terminal of the battery and deposited on it.

Question 11.
How do you appreciate the efforts of Luigi Galvani and Alessandro Volta in discovering a cell and making a stored electric energy available to human beings?
Answer:
We should have to thoroughly appreciate the efforts of Luigi Galvani and Alessandro for their discoveries for the development of mankind. Galvani and Volta completely change the life of human beings. Before that people generated electricity in different ways and conduct various experiments. However they faced one major problem which prevented them from understanding electricity in depth. They did not have a stable and permanent source of electricity. Galvani experimental conclusion was a revolution in science saying that all living beings contained electricity and it was the main source of life.
Volta proved it is possible to generate electricity if two different metals are placed in some liquids. Volta made first cell using zinc and copper dipped in sulphuric acid. This cell called Volta cell. Later dry cell was prepared. Now various appliances works with dry cells. So the efforts of Galvani and Volta should be appreciated by every generation for their contribution to electricity.

Question 12.
Collect the information and make a list of good conductors and bad conductors. Mow do you use this information in your daily life works?
Answer:

Good conductors	Bad conductors
1) Metals	1) Wood
2) Acid solutions	2) Plastic
3) Base solutions	3) Diamond
4) Salt solutions	4) Distilled Water

Applications in daily life: This information is very useful to us. Generally metal or good conductors of electricity are used in electrical appliances, electrical wires, fuse wires, etc. Whereas plastic is a bad conductor is used for electric insulators like gloves, handles of electrical appliances etc. to avoid electric shocks.

Question 13.
Make a battery from four lemons and test it with a LED in the circuit.
(OR)
Write how do you make a battery from four lemons and test it with a LED in the circuit in your laboratory.
Answer:
Take four lemons cut them into two pieces. Take one piece from each lemon and insert two copper wires and connect them in series and connect a LED and complete the circuit. The circuit is shown below.

The bulb glows due to presence of current in the circuit. Here lemon juice acts as electrolyte and copper wires acts as electrolyte. So each lemon piece dipped with a copper wire acts as cell. These cells connected in series forms a battery.

Question 14.
Refer to the activity 3 in this chapter. Start with distilled water. The LED would not glow. Add two drops of some acid to distilled water and check the glow of LED. Add two more drops and check the intensity of the glow. Repeat the activity 5 to 6 times by adding 2 drops of the same acid each time. Do you see any difference in the intensity of glow with increasing acid content of water? What can be inferred from the above observations? Repeat the entire activity by taking a solution of baking soda and adding drops of it to distilled water instead of acid. Write differences and similarities.
Answer:
When we add two drops of acid (namely hydrochloric acid) to distilled water the LED will glow. If we further add the acid another two drops the intensity of glow increases. By repeating same activity 5 or 6 times we observe every time the glow of LED increases. The reason is acid dissociate into ions in aqueous solution. Which allows the passage of current. As the quantity of acid increases there will be more ions available for passage of electricity. So the intensity of glow increases.
We will observe the same result by adding baking soda but the intensity of glow is some what less when compared with addition of acid. The reason is baking soda is a weak base. So the dissociation is less when compared with acid. So less ions are available for passage of electricity. So the intensity of glow of LED is less when compared with acid.

Question 15.
In many of the activities in this chapter, we have used a tester made up of LED. Can we avoid LED and use something else as a tester Magnetic compass needle could be an alternative tester. We know that when we take a current carrying wire near magnetic compass needle, it shows deflection. Use this property to make a tester of magnetic compass needle. You may refer to the following figure.
Answer:
A magnetic compass wound with a copper wire is connected to one end of dry cell. The other end is connected to one of the two metal pins separated by a small gap in a rubber cap. The second pen is connected to the other end of dry cell to completed the circuit.

The magnetic needle deflects because whenever current pass through a wire it acts as a magnet is called magnetic effect of current.

8th Class Physical Science 9th Lesson Electrical Conductivity of Liquids InText Questions and Answers

Think and Discuss

8th Class Physical Science Textbook Page No. 123

Question 1.
Why some material allows electric current to pass through them and why some do not?
Answer:
Flow of charged particles constitutes current. So for the passage of current the material should have charged particles. All the materials do not have charged particles, e.g. Plastic, wood, diamond, etc. So only those material which have charged particles allow passage of current.

8th Class Physical Science Textbook Page No. 127

Question 2.
If a battery is packed in a box and if only two wires from two terminals are given out, how can we decide the positive and negative terminal of the battery?
Answer:
Insert the wires into a potato. A greenish spot is seen on potato at one of the wires. That wire behave like positive terminal and the other is negative terminal.

8th Class Physical Science Textbook Page No. 129

Question 3.
What is electrolysis?
Answer:
The dissociation of a solution of compound into constitute ions or elements by passing current is called electrolysis.
e.g. Electrolysis of water, which produce oxygen and hydrogen gases.

8th Class Physical Science 9th Lesson Electrical Conductivity of Liquids Activities

Activity – 1

Question 1.
Testing the material to know which allows electric current to pass through it.
Answer:
Take a torch bulb or LED (Light Emitting Diode), a dry cell, wooden sheet, two drawing pins, a key (safety pin) and pieces of connecting wires. Set up the electric circuit as shown in the figure.

Place the key on drawing pin. The bulb begins to glow as soon as the key touches the drawing pin. Now replace the key by a nail.
Does the bulb glow ?
Yes, the bulb glows.
Repeat the activity using different types of materials instead of the nail, say a strip of paper, a piece of chalk, a drinking straw, a piece of plastic, a paper clip, a rubber eraser, etc.
Note in each case whether the bulb glows or not and enter your observations in table.

Object	Material	Bulb glows Yes/No	Good conductor/ bad or poor conductor
Nail	Iron	Yes	Good conductor
Eraser	Rubber	No	Bad or poor conductor
Paper	Cellulose	No	Bad or poor conductor
Chalk	Calcium carbonate	No	Bad or poor conductor
Straw	Plastic	No	Bad or poor conductor
Plastic	Plastic	No	Bad or poor conductor
Matchstick	Wood	No	Bad or poor conductor

From the above activity, we conclude that some material allow electric current to pass through them. What we call them?
They are called good conductors of electricity.
The material that do not allow current to pass through them, what is the name given to those material?
They are named as bad or poor conductors of electricity.

Activity – 2

Question 2.
Testing the electric conductivity of liquids.
(OR)
Conduct an experiment for testing the electric conductivity of liquids.
Answer:
Take a LED, dry cell, metal pins, rubber cap of injection bottle and wires for making connections. Set up an electric
circuit shown in the figure.

See that the two metal pins, pass through the cap and should have a very small gap (around 2 mm) between them so that the pins are fairly closer but not touching each other. The LED should not glow when pins are separated by small distance.
Now, join the free ends of pins together by pressing them for a moment and make sure that the LED glows. Release the pins they get separated and LED should not glow. This acts as a tester.
Fill the rubber cap with different liquids like distilled water that we drink, coconut oil, kerosene, lime juice, mustard oil, sugar solution, etc one after another and in each case check whether the LED glows or not. Note down your observations in table.

Liquid	LED glows	Good conductor/ poor or bad conductor
Distilled water	No	Bad conductor
Drinking water	Yes	Good conductor
Coconut oil	No	Bad conductor
Lemon juice	Yes	Good conductor
Vinegar	Yes	Good conductor
Kerosene	No	Bad conductor
Vegetable oil	No	Bad conductor
Sugar solution	No	Bad conductor
Common salt solution	Yes	Good conductor
Milk	No	Bad conductor

a) Why doesn’t the LED glow in all the cases? Or why doesn’t the LED remain off in all the cases?
Answer:
The LED doesn’t glow all the cases because when the liquid the two pins of tester allows electric current to pass through, the circuit is completed (closed) and the LED glows. On the other hand when the liquid does not allow the current to pass through, the circuit is incomplete (open) and the LED does not glow.

b) In the above activity, you may have observed that in all those cases where the LED glows, its brightness (intensity) is not the same. Sometimes it may be brighter and sometimes it may be relatively dimmer. Why is that so?
Answer:
The intensity of the glow of the LED depends on the flow of electric current through the circuit. Although a liquid may be a conductor, it may not allow current through it as easily as a metal does.
As a result although the circuit is completed and the LED glows, due to weak current in case of some of the liquids, the intensity of glow would be lower compared to other liquids.

Activity – 3

Question 3.
Transforming a poor electric conductor into a good conductor.
(OR)
Conduct an experiment for testing the electric conductivity of electrolyte.
Answer:
Take some amount of distilled water in three different containers. Dissolve small quantity of common salt in the water of first container. Dissolve the copper sulphate, lemon juice in second and third container respectively.
Use the tester that we used in activity 2, and repeat the activity 2. Note the observations in table.

Material ‘	Does the LED glow? Yes/No	Good conductor/bad conductor
Distilled water	No	Bad conductor
Distilled water + salt	Yes	Good conductor
Distilled water + CuSO4	Yes	Good conductor
Distilled water + lemon juice	Yes	Good conductor

a) From table what can we infer?
Answer:
Distilled water does not allow the electric current to pass. Water in its pure form is a bad conductor of electricity. But when water contains salts or acids, it allows a passage of electric current and turns into a good conductor of electricity.

b) Do you understand why you are advised not to touch electric appliances with wet hands?
Answer:
Water with salts is a good conductor of electricity and the current flowing through househt d electric appliances is very high. Therefore we should never touch the electrical appliances with wet hands.

Activity – 4

Question 4.
Testing the effect of electric current on potato.
Take a potato. Cut into two halves and take one half of it. Construct tester with LED bulb. Insert two copper wires of the tester into the potato. Leaving some distance (around 1 cm) between them.

a) Dose the LED glow?
Answer:
Yes, the LED glows.
Leave the inserted wires for 20-30 minutes.

b) What do you observe the surface of the potato?
Answer:
A greenish blue spot is seen on the potato around the wire connected to the positive terminal of the battery.
But no such spot is seen around the other wire connected to the negative terminal. This greenish spot is due to chemical change in the potato.

c) What could be the cause behind this change?
Answer:
There is chemical change occurred in the potato.

d) Will other vegetables also show such an effect?
Answer:
Vegetable like carrot, beetroot, cucumber, radish, sweet potato show the chemical change there by the LED glows.

Activity – 5

Question 5.
Make your own cell.
(OR)
Draw the diagram of electrolytic cell and explain.
Collect two injection bottles. Cut two 5 cm long bits of thick copper wire. Use sandpaper to scrap about 1 cm of the coating off both ends of the wires.
Break open a exhausted dry cell and remove its outer metal covering (made of zinc). Cut two 2 mm wide and 5 cm long strips from this zinc plate. Insert the copper wires and zinc strips into the rubber caps of the injection bottles as shown in figure. Ensure that the copper wire and zinc strips do not touch each other.

Now take a wire and connect the copper wire of one bottle with the zinc plate of the other bottle. Fill both bottles with dilute sulphuric acid. Carefully close the bottles with the caps in which copper wires and zinc strips are inserted. Your cell is ready.
How will you test it?
Take an LED. Attach two wires to its two terminals. Touch the wire from one terminal to the zinc plate and the wire from other terminal to the copper wire. Did the LED light up ? If not, change the connections vice-versa. Did the LED glow ?
Repeat the above activity using lemon juice, tamarind juice and tomato juice one by one instead of sulphuric acid to make cells.

a) What other liquids can be used to make the cell?
Answer:
Acid solutions.

b) Will detergent solution be useful?
Answer:
Yes, it is useful.

c) How does above cell function?
Answer:
After a few seconds of immersion of zinc and copper into dilute sulphuric acid, zinc slowly begins to dissolve in the sulphuric acid. We can see bubbles getting formed on the copper rod.
The current is passed from copper rod to zinc rod. Here chemical energy is converted into electric energy by electrolysis method.

d) Can you compare this cell with dry cell?
Answer:
In the above cell electrolyte is dilute sulphuric acid whereas in dry cell ammonium chloride paste is electrolyte. The electrodes in above cell is copper and zinc, whereas in dry cell it is graphite (carbon) and zinc.

e) Which is good one? Why?
Answer:
Dry cell is better than ordinary Volta cell. The reason dry cell does not have any fluids. So it is easy to carry dry cell compared with volta cell. So dry cell is better than volta cell.

SCERT AP Board 7th Class Social Solutions 1st Lesson Reading Maps of Different Kinds Textbook Questions and Answers.

AP State Syllabus 7th Class Social Studies Solutions 1st Lesson Reading Maps of Different Kinds

7th Class Social Studies 1st Lesson Reading Maps of Different Kinds Textbook Questions and Answers

Improve Your Learning

Question 1.
Why are the levels of all the seas equal in the world?
Answer:
All heights on the land are calculated from the sea level. Since all seas in the world are connected to each other, more or less the sea level (the top surface) all over the world is taken to be roughly the same.
We can easily observe this in the picture given below.

The temple is 100 meters high above sea level. The top of the hill is 150 meters high from sea level.
Thus we can say the levels of all the seas are equal in the world.

Question 2.
How is the sea level measured?
Answer:
The level of the sea keeps changing. So the level of the sea is carefully measured at frequent intervals and the mean level of the sea is calculated. A tidal gauge is used to measure the rising and falling of the sea.

Question 3.
What are the uses of maps showing heights?
Answer:

1. These maps help us to understand the nature of the terrain, where the mountains are, where the valleys are, etc.
2. If we look at the physical map of Andhra Pradesh, we can identify the coastal plains that run along the coast of the Bay of Bengal.
3. If we travel westwards from the coast, we will reach hills that form the “escarpments” to the plateau region.
4. The plateau region itself is cut by many rivers like the Krishna and the Godavari which form deep and broad valleys in them.
5. Maps showing heights are very essential when roads or dams have to be constructed.
6. If we have to lay roads in an undulating region between two places, such maps help us in deciding the route to be taken by the road.
7. Similarly, when dams are planned it is necessary to know how much land will be submerged by the water of the dam.

Question 4.
What differences do you find between the lifestyle of people living on high altitudes and low altitudes?
Answer:
Difference between the people living on the high and low altitudes:

People of High Altitudes	People of Low Altitudes
1) They live in mountainous regions.	1) They live in plains.
2) They are economically backward.	2) They are economically well developed.
3) They wear woolen clothes.	3) They wear cotton and silk clothes.
4) They enjoy insecure life.	4) They enjoy secure life.

Question 5.
How are maps helpful to people?
Answer:

1. The map is a representation or a drawing of the total or a part of the earth’s surface drawn on a flat surface according to a scale.
2. Maps help us to study a part of the earth.
3. Maps provide more information than a globe.
4. Maps are easy to carry and take the measurement too.
5. Some maps tell us about how high or low the places are, some tell us about how much it rains there or how hot or cold it gets there.
6. Some maps tell us about crops that grow there or the kinds of forests there are.
7. By studying them we can know much about a place.

Question 6.
Read the para ‘Contour Lines’ and comment on it.
Contour Lines
A contour is a line joining the places with equal heights. On the map of Nimpur you would have seen that there is a line passing through the village, this is the 50-meter contour line. All places on this line will have the same height of 50 meters. Contour lines will be in irregular shape depending upon the landform. These cannot cut with each other. The distance between two contour lines will depend upon the landscape. If the land has a steep climb then the contour lines will be near to each other. If the slope of the land is gentle, then the contour lines will be quite far from each other.
Answer:
A contour line of a function of two variables is a curve along which the function has a constant value. In cartography, a contour line joins points of equal elevation above a given level, such as mean sea level.
Contour lines are curved, straight or a mixture of both lines on a map describing the intersection of a real surface with one or more horizontal plains.

Question 7.
Observe the physical map of Andhra Pradesh and list out the districts which are above 150 M.S.L.?

Answer:
The following districts are above 150 mts Mean Sea level.

1. Chittoor
2. Visakhapatnam
3. Kurnool
4. Anantapur.

AP State Board Syllabus AP SSC 10th Class English Textbook Solutions Chapter 1C I Will Do It Textbook Questions and Answers.

AP State Syllabus SSC 10th Class English Solutions Chapter 1C I Will Do It

10th Class English Chapter 1C I Will Do It Textbook Questions and Answers

Comprehension

I. Answer the following questions briefly.

Question 1.
What is the ultimate aim of a bright student? And why?
Answer:
The ultimate aim of a bright student is to continue his/her studies at a world-class educational institute. He/She wants to join it as there are high standards. One will do great things when one studies at a top-class institute. So, a bright student wants to join a top-ranked institute.
(Or)
The ultimate aim of a bright student is to study at IIT. It is because, these institutions maintain high standards. One can do big things if one studies at IIT. Hence, a bright student’s ultimate aim is to study at IIT.

Question 2.
‘His heart sank in sorrow.’ Whose heart sank in sorrow? Why?
Answer:
Narayana Murthy’s heart sank in sorrow. Because of the poor financial position, Murthy’s father refused to send him to IIT. Though he had passed with a high rank, there was no chance for him to study at IIT which was his dream. So, he was very sorrowful.

Question 3.
How did Murthy react when his father expressed his helplessness to send him to IIT?
Answer:
When his father expressed his helplessness to send him to IIT, Murthy was disappointed. It seemed his dreams had burnt to ashes. His heart sank in sorrow. He didn’t share his feelings with anybody. His heart was bleeding but he didn’t get angry with anybody.

Question 4.
The author calls Murthy an introvert. Which action of Murthy substantiates this claim of the author about Murthy?
Answer:
‘Introvert’ means someone who is quiet and shy, and does not enjoy being with other people. When Murthy’s father refused to send him to IIT, he became sorrowful. Though he was sorrowful, he never shared his unhappiness or helplessness with anybody. He did not reply. He remained silent. So, we can say that Murthy was an introvert by nature.

Question 5.
What, according to Narayana Murthy, can change the life of a person?
Answer:
According to Narayana Murthy, a person himself can change his life by hard work. It is not the institution or any other thing that can change the life of a person.

Question 6.
How does the motto ‘Powered by intellect and driven by values’ describe Murthy’s life?
Answer:
Murthy really believes in the motto, ‘Powered by intellect and driven by values’. He worked very hard. He didn’t bother about his personal life or comforts. He was a genius right from the beginning. He shared his wealth with others. He never used the help of any caste, community or political connections to go up in life. He proved that it was possible to earn wealth legally and ethically. He built a team of people who were equally good. The above words reveal that he was powered by intellect and driven by values.

II. Given below are some sentences from the lesson. What do they tell us about Narayana Murthy’s qualities? Use the adjectives given in the box to describe Murthy’s character. You may also use some more adjectives you like.


Answer:

Sentences from the lesson	Aspects of Murthy’s character
1. His seniors used to ask him to solve their difficulties in science.	bright
2. He was a guide for the others.	intelligent
3. While others struggle to solve the problems in the question papers, he would smile shyly and solve them in no time.	brilliant
4. His principle was never to hurt anyone.	gentle
5. He did not reply. He never shared his unhappiness or helplessness with anybody.	introverted
6. He went to station to say goodbye and good luck to them for their future life.	encouraging
7. He never used the help of any caste, community or political connections to go up in life.	uncompromising
8. He built a team of people who were equally good.	hard-working

Vocabulary

Let’s look at some more one-word substitutes.

Word	Meaning
fatalist	a person who believes in fate
centenarian	a person who is above hundred years
omnipresent	one who is present everywhere
mercenary	a person who can do anything for money
misogynist	one who hates women
monogamy	a practice of having one wife or husband
autobiography	a life history written by oneself
biography	a life history written by somebody else
honorary	a position for which no salary is paid
ambiguous	a sentence whose meaning is unclear
inimitable	that which cannot be imitated
theist	one who believes in God
spendthrift	one who spends too much
teetotaler	one who abstains from taking alcohol

Tick (✓) the most appropriate one-word substitutes for the following.
1. A person or thing that cannot be corrected
a) unintelligible
b) Indelible
c) illegible
d) incorrigible
Answer: d

2. A persoiì of good understanding. knowledge and reasoning power
a) expert
b) intellectual
c) snob
d) literate
Answer: b

3. A person who knows many languages
a) linguist
b) grammarian
c) polyglot
d) bilingual
Answer: c

4. One who possesses many talents
a) versatile
b) prodigy
c) exceptional
d) gifted
Answer: a

5. Words inscribed on a tomb
a) epitome
b) epistle
c) epilogue
d) epitaph
Answer: d

Project Work

You have read about Nick Vujicic, who has accomplished every seemingly impossible thing in life despite having the most difficult form of disability. You have read about Narayana Murthy, who is one of the most remarkable examples to win over the unbeatable difficulties. You may also have heard or read about some remarkable Indian women such as Sudha Murthy, Sudha Chandran, Kiran Bedi and many other women who have crossed all the hurdles to become successful.

Now, work in pairs and collect information about the women who you think have excelled in their lives though they may not have come into limelight.

You may read articles in newspapers, magazines, books (autobiographies, biogra¬phies etc.), browse internet and watch TV reports on women.

Answer:

Name of the woman	Details eg. birth, childhood, education, etc.	Challenges they faced/disabilities they have / had	Remarkable achievements	The qualities that inspired you
Mary Griffith	A 13 year old girl. She is studying at Mundelein Middle School	She has cerebral palsy	Set records at the National Junior Disabi­lity Champion­ship.	Hard work and will power
Karin Korb	A 38-year-old woman. She spent her childhood with her grandparents. She had studied well till she broke her back. Later she joined a law school.	She broke her back at age 17 while competing in gymnastics.	Wheelchair tennis competitor	Courage and determination
Emily Anne Schaefer	A 44 year old woman. A French town resident. She spent her childhood in a foster s care.	When she was a child, she suffe­red from trauma­tic brain injuries. She is develop­mentally disabled.	The facilitator for the project’s network in Hunterdon County. Despite the trauma, she earned a college degree in fine arts. She is a printmaker and painter, and has self- published two books on art and poetry,	Grit and perseverance
Rama Lakshmi	She is the resident of T. Nagar, Tamil Nadu. She was born on 20th May, 1995. Spent her childhood very joyously till she lost her sight in a ghastly incident. Now she is a stu­dent of engineering.	She became blind when she was 12 years old in an accident.	She is a play­wright and poet. She has written more than twenty poems and eight plays,	Courage and determination
Srivalli	She is the resident of Kothapet, Kurnool. She was born in a poor family on 15th August, 1992. She took her degree in arts with distinc­tion marks.	She lost both her legs in an accident.	She is a wonder­ful singer. She composes songs.	Will power, determination perseverance

I. Based on the information you gather about the persons, prepare a short biographical account of the person you like the most, emphasizing the exemplary work done by him/her and present it to the group/ whole class.
Answer:
Ms. Srivalli was born on 15th August, 1992. She came from a poor family. Her father was a musician and her mother was a teacher. She was a bright student. Unfortunately, she met with an accident when she was eleven and the doctors amputated both her legs. After two years of relentless struggle, she could go back to her school. She could walk with the help of artificial limbs and slowly run. Now, she can do anything like a normal woman. She learnt music from guru Rama Sastry and now she is a good singer and composer of songs. In spite of her disability, she has worked hard with great determination, discipline and dedication and achieved her target.

After she had met with the accident, her heart sank in sorrow. Sometimes she wanted to die. She hated God for doing this to her. She was terrified of her losing both the limbs. Her doctor Mr. Rao always encouraged her by telling her that she could walk and run normally. She tried and tried until she could walk. She didn’t give up at any stage. Srivalli always says, “The challenges in our lives are there to strengthen our convictions. They are not there to run us over.” With the help of her parents, friends . and guru, Srivalli has managed to reach such a position in her life. She has proved that anything can be done, if one tries hard. From her life, we can understand that one need not lose hope. Her life shows us that one s disability can’t prevent one from reaching one’s target. I feel that her life is a source of inspiration to every woman. She is able to do all these only because of her strong will power. Hence, I believe in will power with which one can achieve wonders in one’s life. I would like to wish all the best for her in the future.

II. You may also present this write up on the occasion of “Women’s Day” in your school.
Answer:
Our beloved headmaster, dear teachers and my fellow students!
I wish you a very good morning and welcome you all to the programme. At the outset, I would like to greet all the women a very happy ‘Women’s Day.’

As we all know that 8th March is celebrated as International Women’s Day to commemorate women’s achievements and the contributions made by them to the society This day is also known as the United Nations Day for women’s rights and international peace.

I have a great pleasure to say a few words about a great girl Mary Griffith on this occasion. Mary Griffith, a thirteen year old girl, has set national records in track and swimming. She has been studying at the Mundelein Middle School and has cerebral palsy. In spite of her disability she set her records in 2004 and 2005 at the National Junior Disability Championships. She always say that sports have given her a lot more confidence and taught her to balance her life. Though she has been suffering from cerebral palsy, she hasn’t lost her hope. With great faith and determination she has done so well and set her own records. Her efforts are inspirational to all the women.

We all wish her a great future and with this I will end my speech. I thank one and all for giving me this chance to share my views with you.

I Will Do It Summary in English

Nagavara Ramarao Narayana Murthy is the founder of Infosys, a leading IT company in the world. He is an icon of simplicity, uncompromising quality and fairness, apart from being a philanthropist. He believes in the motto, ‘Powered by intellect and driven by values.’

As a school going lad, Narayana Murthy was the brightest boy in his class. He could solve the most difficult problems which were very hard for his seniors. He came from a poor but educated family. His father was a high-school teacher. As all other students, Narayana Murthy wanted to get admission in the IIT. He appeared for the entrance test and did well. He always dreamt of studying at IIT. He was thrilled to know that he had passed the test with a high rank.

When Narayana Murthy told his father that he wanted to join IIT, his father reminded him of their poverty. Murthy’s father advised him to stay in Mysore and study as much as he wanted. His father was very sad to say this. Murthy was disappointed and his heart sank in sorrow. He was an introvert so he never shared his sorrowfulness or helplessness with anybody. When his classmates were leaving for Madras, Murthy went to the station to say goodbye to them. Though they were all excited and talking loudly, Murthy remained silent. He wished them and they waved at him as the train slowly left the platform. Even after the train had left, he stood there motionless. He believed that he only could change his life by hard work. He unknowingly followed “Your best friend is yourself and your worst enemy is yourself, the philosophy of the Bhagavath Gita. With great determination, Narayana Murthy reached great heights in his life. He proved that it was possible to earn wealth legally and ethically.

I Will Do It about the Author

Sudha Murthy, wife of N.R. Narayana Murthy, is an Indian social worker and author. Murthy began her professional career as a computer scientist and engineer. She is the chairperson of the Infosys Foundation. She has founded several orphanages, participated in rural development efforts, supported the movement to provide all Karnataka government schools with computer and library facilities, and established the ‘The Murthy Classical Library of India’ at Harvard University.

Murthy also teaches Computer Science. She composed a fiction, Dollar Sose. The present story is an extract from one of her most successful stories ‘How I Taught my Grandmother to Read & Other Stories.’

I Will Do It Glossary

sharp (adj): quick to notice something/able to grasp quickly

bright (adj): clever / intelligent / sharp / brilliant

unnoticed (adj): ignored / overlooked

spark (n): a small amount of particular quality or feeling

grasp (v): understand something completely

avid (adj): doing something as much as possible

literature (n): written works like novels, plays, poems, technical works, newspapers and magazines

admission (n): the right to join an institution

aspirant (n): someone who hopes to get a position of importance or honour

sleepy (adj): quiet and peaceful

guide (n): a person who can advise others

mandap (n): a raised platform

uitlmate (adj): main and most important / vital / final

D-Day (n): a date on which something important is expected to happen.(From the name given to June 6, 1944. the day on which the US., British, and other armies landed on the beaches of northern France in the Second World War.)

Implied (v): gave the meaning / meant

Anna (n): a word used to address a respectable elder 1 older male

afford (v): pay for / have funds for

expenses (n): expenditure / money that one spends on something

bitter (adj): making somebody feel unhappy

burnt to ashes: lost hopes

fondest (adj): most liking

introvert(n): a quite person who is interested in his / her own thoughts and feelings.

chirping (v): making short high sounds

monsoon (n): rainy season

set in (phr.v.): begin / start

drizzle (v): light rain / sprinkle

motionless (adj): without movement

jealously (adv): being unhappy over something

philosophy (n): attitude / way of life

ethically (adv): morally

pioneer (n): a person who is the first to do something

wave (n): raise or increase

icon (n): a famous person or thing that people admire and see as a symbol of a particular idea, way of life, etc.

uncompromising (adj): unwilling to change opinions or behaviour

philanthropist (n): one who devotes his service or wealth for the love of mankind

powered by intellect and driven by values: According to Narayana Murthy Intellect (mind power) should be the power of every man. He should be driven (influenced) by values.

AP State Syllabus AP Board 8th Class Physical Science Important Questions Chapter 4 Synthetic Fibres and Plastics

AP State Syllabus 8th Class Physical Science Important Questions 4th Lesson Synthetic Fibres and Plastics

8th Class Physical Science 4th Lesson Synthetic Fibres and Plastics 1 Mark Important Questions and Answers

Question 1.
What is polymer?
Answer:
Many small identical units combine to form a large unit is called polymer. The small units are called monomers.

Question 2.
What are synthetic fibres?
Answer:
The fibres obtained from petrochemicals when they are subjected to chemical processes are called synthetic fibres.
Have you ever heard a cracking sound when you take off certain type of clothes? or did you see sparks in them when it is dark?

Question 3.
What is the reason?
Answer:
This is static electricity developed by artificial fibres due to friction.

Question 4.
Why does wearing nylon clothes are not preferable while cooking or working near a fire?
Answer:
Nylon fibre easily catches fire. So it is not preferable to wear it while cooking, welding, working near a fire.

Question 5.
What is blending and what is the advantage of blending?
Answer:
Any synthetic fibre can be combined with two or more other fibres is called blending.
When two fibres are blended the resultant blended fibre possess the best qualities of both.

Question 6.
What are the uses of plastics?
Answer:
Plastics are used in milk and oil pouches, containers to store pickles and rice, buckets to store water, chairs, water pipes, electrical appliances, television, radio and comput¬ers and mobile phones.

Question 7.
What material is used to make handles of utensils?
Answer:
Bakelite is used for making handles of various utensils due to its poor conductivity of heat and electricity.

Question 8.
How do you appreciate 4R principle?
Answer:
4R principle is useful in developing ecofriendly environment and bright future for next generation of people.

8th Class Physical Science 4th Lesson Synthetic Fibres and Plastics 2 Marks Important Questions and Answers

Question 1.
How is nylon made? What are the advantages of nylon as fibre?
Answer:
Nylon is a polymer made of chemical units called polyamides.
Advantages of nylon as fibre:

1. Nylon fibre is strong, elastic and light weight.
2. Cloth made of nylon are lustrous and easy to wash.
3. Nylon does not absorb water.

Question 2.
Where does we use nylon?
Answer:
Nylon can be used in tooth brush bristles, ropes, fishing nets, tents, sarees, stockings and socks, car seat belts, sleeping bags, curtains, carpets and also used in making parachutes.
Rock climbers use nylon ropes to climb mountains. It is also used in making of swim suits, sheer hosiery, sails, umbrella cloth, dress materials, car tyres, etc.

Question 3.
How would you prepare rayon?
Answer:
The cellulose that was collected from wood or bamboo pulp is treated with sodium hydroxide and then carbon disulphide. It forms a syrup called viscose. Viscose is forced through a spinneret into a solution of dilute sulphuric acid. This gives us silk like threads. This new fibre is called rayon which is an artificial silk.

Question 4.
What are the uses of rayon?
Answer:

1. Rayon is cheaper than silk and can be woven like silk fibre.
2. Rayon is mixed with cotton to make bed sheets.
3. Rayon is mixed with wool in making of carpets.
4. Rayon is often used in fashion and home furnishings.
5. Rayon is also found in sanitary products, diapers and bandages and lints for dressing wounds.

Question 5.
What is acrylic ? Where do we use acrylic?
Answer:
Acrylic is a synthetic fibre made from the combination of coal, air, water and lime¬stone. It looks like natural wool. If can be considered as artificial wool.
It is used in knitted apparels such as fleece, socks, sportswear and sweaters. It is also used in craft yarns, upholstery fabric, carpets, luggage yawning and vehicle covers.

Question 6.
What are the advantages of natural fibre over artificial fibres?
Answer:
When natural fibres, contribute to a fabric it allows the skin to breathe easily. Also natural fibres are generally free from irritating chemicals. Whenever fire accidents takes place they does not stick to the body.

Question 7.
How do you prepare polyester? What are the advantages of polyester as fabric?
Answer: Polyester is made by reacting dicarboxylic acid with dihydric alcohol.
Advantages :

1. Polyester can be melted and spun. This property allows the fibre to convert into different sizes and shapes.
2. They are altra thin, microfiber which gives them a smoothen and soft feel.
3. They does not get wrinkled easily.
4. It remains crisp and easily washable.

Question 8.
Give example for popular polyester and what are its advantages?
Answer:
The popular polyester is terylene.

1. It can be drawn into very fire fabric fibres.
2. Terylene is after mixed with cotton to form terricot with wool to give terriwool. Which has best qualities of both blunded fibres.

Question 9.
What are plastics? How many types of plastics are there? Explain them with examples.
Answer:
Organic polymers are called plastics. Plastics are two types :

1. Thermoplastics: The plastics which get deformed easily on heating and can be bent are called thermoplastics, e.g.: Polyethene, PVC.
2. Thermosetting plastics: The plastics which molded once cannot be softened on heating are called thermosetting plastics, e.g.: Bakelite, melamine.

Question 10.
Where do we use bakelite?
Answer:

1. Bakelite is used for making handles of various utensils.
2. It is used for making electrical appliances including switch boards.
3. It is an alternative for pearl and jade.
4. In manufacture of telephone.

Question 11.
Where do we use melamine?
Answer:

1. Melamine is used in making of utensils and other grocery of kitchen.
2. It is used for making of floor and dress material (firemen dress) for their nature of fire resistance.
3. Computer and T.V. cabinets are made by melamine.

Question 12.
Ramu observing his grandmother keeping pickles in plastic bottles. What are the questions raised in his mind by seeing this?
Answer:
The questions raised in Ramu’s mind

1. Whether plastic is cheap when compare with metal?
2. Why does she not put the pickles in metal containers?
3. Whether metal containers react with pickles? If so they form harmful substances?

Question 13.
What do you know about creator of first man made plastic? How he prepare the plastic?
Answer:
The creator of first man made plastic is Alexander Parkes the name of the plastic is parkesine.
To prepare this material Parkes heated nitrated cotton which previously soaked in sulphuric acid and made fabric soft and elastic with oil and camphor. The end product was an ivory – coloured material that became distorted when subjected to heat. This is named as Parkesine.

Question 14.
What do you know about father of plastic industry? What are his major inventions and discoveries?
Answer:
Dr. Baekeland is considered as the father of present plastic industry. He was respon¬sible for the invention of bakelite. He accidently discovered the compound of carbolic acid and formaldehyde. When he tried to reheat the solidified compound he discovered it would not melt, no matter how high the temperature would be.

Question 15.
List out the objects made up of Acrylic.
Answer:

1. It is used in knitted apparels such as fleece, socks, sports wear and sweaters.
2. It is also used in craft yarns, upholstery fabric, carpets, lugguage awnings and vehicle covers.

Question 16.
Draw and explain the diagram of Universal recycling symbol.
Answer:
When the number is omitted from recycling icon then it is known as Universal recycling symbol.

Question 17.
What are thermosetting plastics? Give two examples.
Answer:
Thermosetting plastics are synthetic materials which gain strength during moulding by heating, but cannot be remoulded or reheated after their initial heat, moulding.
Ex : Bakelite and melamine.

Question 18.
What made the human beings to search for the alternative for natural fibres?
Answer:
Human being is always going in search of new things which can make his life more comfortable and durable. As the natural fibres are not durable, elastic or light weight or lustrous or easy to wash, he needed an alternative to fulfill his expectations. The solution to his expectations is synthetic fibre.

Question 19.
Imagine what would happen if we do not discover plastics.
Answer:
Nowadays every object used in our day to day life is made of plastic. For example milk and oil pouches, containers to store pickles and rice, buckets to store water, chains, water pipes, electrical appliances, television, radio and computers, mobile phones.
So plastics has taken over the place occupied by metal wood and glass items due to its special properties. So we cannot imagine our life without plastics because it is part of each and every aspect of life.

Question 20.
What is the most common material used in making the household articles ? Give some examples.
Answer:
Mostly household articles are made up of plastics.
Milk and oil pouches, containers to store pickles and rice, buckets to store water, chairs, water pipes, electric appliances, television, radio and computers, mobile phones, etc. are made of plastic.

Question 21.
What are the properties of thermoplastics and thermosetting plastics ?
Answer:
Thermoplastic will soften when heated and harden when cooled. It is a polymer that turns into a liquid when heated and freezes to a very glassy state when cooled sufficiently. Thermosetting plastics are not remouldable or reheatable. They are poor conductors of heat and electricity. They are fire resistants.

Question 22.
Why polyster is quite suitable for making dress materials ? Name any two types of polyesters and their uses.
Answer:
a) Fabric made from polyester does not wrinkled easily.
b) If remains crisp and it is easy to wash.
c) Terylene is a type of popular polyester.
d) It can be drawn into very fine fibres that can be woven like any other yarn.
e) PET is very familiar form of polyester. It is used for making bottles, utensils, films, wires and many other useful products.

Question 23.
Write some disadvantages of synthetic fibres.
Answer:
a) Synthetic fibres cannot absorb moisture, thus they cannot be used as dress materials during summer.
b) They are dangerous to be worn near fire or heat as they catch fire easily.
c) They cannot be easily ironed.

Question 24.
Explain why plastic containers are favoured for storing food.
Answer:
Three main advantages of using plastic containers for storing food are :
a) They do not react with food items
b) They do not get rusted
c) They are light, strong and durable

Question 25.
Explain why the following are made of thermosetting plastics,
a) saucepan handles
b) electric plugs/switches.
Answer:
Above things are made up of bakelite (thermosetting plastic) because it is
a) bad conductor of heat
b) poor conductor of electricity.

8th Class Physical Science 4th Lesson Synthetic Fibres and Plastics 4 Marks Important Questions and Answers

Question 1.
Explain 4R principle for creating ecofriendly environment.
Answer:
The 4R principle involves 1) Reduce 2) Reuse 3) Recycle 4) Recover.

1. Reduce: Reduce the usage of plastic to avoid its negative consequence on environment. Land filling or plastics and burning of plastics in incinerators in the way of disposal of plastics. These have negative consequence on environment. So reduce the usage of plastic whenever it is possible.
2. Reuse: Articles made of plastic is used again and again for its optimum utilization. There by we can decrease the usage of plastics.
3. Recycle: We can recycle the plastic material from broken plastic material that will decrease the production of excess of plastic.
4. Recover: The principle of recover plays major role in plastic waste management. The solid waste should be converted into resources such as electricity, heat, compost and fuel through thermal and biological means.

(OR)

1. Reduce: Try to use less plastic material in our daily life.
2. Reuse: Whenever we need to use plastic material, use the same material again and again don’t go for new one every time.
3. Recycle: Instead of throw away the waste plastic material try to give it the vendor.
4. Recover: Aware the people about establishing “garbage to energy” plant in your area.

Question 2.
Is there any such effort for solid waste management taking place in your village/ town ? How do you appreciate 4R principle?
Answer:
4R Principle is for creating an eco friendly environment.
4R = Reduce, Reuse, Recycle and Recover.
Reduce: Reducing the usage of plastics by reusing them helps the negative conse-quences on environment.
Reuse: When some things made of plastics are not in use to us, we can give them to others who need them. This helps the negative consequence or environment. This is eco friendly.
Recycle: In this process, we can obtain a new substance from the old plastics. Recycling can be used to obtain materials from which the original products were made.
Recover: The solid wastes in which plastics are major should be converted into resources such as electricity, heat, compost and fuel through thermal and biological means.
In these ways 4R principle is eco-friendly.

Question 3.
Explain the differences between the thermoplastics and thermosetting plastics with help of a diagram explaining in terms of arrangements of monomers.
Answer:

Thermoplastics	Thermosetting plastics
Plastics which get deformed easily on heating and can be bent are known as thermoplastics. Ex: PVC, polythene bags, toys, combs, etc.	Plastics which moulded once can’t be softened by heating are called thermo­setting plastics. Ex : Bakelite and melamine.

Explanation:

1. Thermoplastics have linear arrangement of monomers.
2. But thermosetting plastics have cross linked arrangement.
3. The difference in the arrangement of monomers bring the difference in their properties.

Question 4.
Do you know how various synthetic fibres are obtained ?
Answer:
Nylon:
Nylon is a polymer made of chemical units called polyamides which contain carbon, oxygen and nitrogen. Polyamides are melted and forced through a heated spinneret which has very, very tiny holes. The size and shape of the holes changes, the characteristics of the resulting fibre. The fibre solidifies as it cool and can be spun or woven.

Rayon:
The cellulose that was collected from wood or bamboo pulp, is treated with several chemicals.
First sodium hydroxide is added and then carbon disulphide to the cellulose.
The cellulose dissolves in chemicals add to it and gives a syrup called viscose. Viscose is forced through a spinneret, into a solution of dilute sulphuric acid. This gives us silk like threads. The threads are cleaned with soap and dried. This new fibre is called rayon.

Acrylic:
It is made from the combination of coal, air, water, oil and limestone. It is spun by either dry spinning or wet spinning.
In dry spinning the dissolved polymers are extruded into warm air. The fibres solidify by evaporation. In wet spinning the polymers are dissolved and extruded into a bath and then dried.

Question 5.
Can you name the few things made up of i) nylon ii) rayon (iii) acrylic and (iv) polyesters ?
Answer:
The things made from nylon:
Tooth brush bristles, ropes, fishing nets, tents, sarees, stockings and socks, car seat belts, sleeping bags, curtains, etc. are made up of nylon. The things made from rayon: Bed sheets, carpets, home furnishings, sanitary products, diapers and bandages and lints for dressing wounds.
The things made from acrylic: Socks, sportswear and sweaters, craft yarns, upholstery fabrics, carpets, luggage, awnings and vehicle covers.
The things made from Polyester: PET bottles, utensils, films, wires, etc.

Question 6.
Why it is advised not to wear synthetic clothes while working in a laboratory or working with fire in the kitchen ?
Answer:

1. The synthetic fibres melt on heating.
2. This is actually a disadvantage with synthetic fibres.
3. If the cloth catches fire it can be very disastrous.
4. The fabric melts and sticks to the body of the person wearing it.
5. It is therefore advised not to wear synthetic clothes while working in a laboratory or working with fire in the kitchen.

Question 7.
Classify the material as biodegradable and non-biodegradable.

1. paper
2. wood
3. metals
4. cotton cloth
5. plastic container
6. woolen sweater
7. peels of vegetable and fruit

Answer:

Material	Biodegradable/non-biodegradable
1. paper	Biodegradable
2. wood	Biodegradable
3. metals	Non-biodegradable
4. cotton cloth	Biodegradable
5. plastic container	Non-biodegradable
6. woolen sweater	Biodegradable
7. peels of vegetable and fruit	Biodegradable

Question 8.
Write short notes on the following.
a) Plastic and health care industry b) Plastic cookware c) Teflon d) Fire proof plastic.
Answer:
a) Plastic and health care industry : Plastics find extensive use in the health care industry. Some examples of their use in health care are the packing of tablets, threads used for stitching wounds, syringes, doctor’s gloves, a number of medical instruments, etc.
b) Plastic cookware: Plastic cookware is used in microwave ovens for cooking food. The heating process is different in microwave ovens. The heat cooks the food but does not affect the plastic vessel.
c) Teflon: Teflon is a non-stick plastic used as non-stick coating in cookwares. It is also used as tape for sealing purpose.
d) Fire proof plastics: Although synthetic fibres catches fire easily, it is interesting to know that the fire proof material is made from synthetic plastics.

8th Class Physical Science 4th Lesson Synthetic Fibres and Plastics Important Questions and Answers

Question 1.
State government decided to avoid Flexi Banners. Predict the effect of Flexi banners
on environment.
Answer:

1. PVC flexi banners can take several years to decompose in land fills.
2. These flexi banners contain dangerous chemical additives like lead, cadmium which can be toxic to our health as well as animals health.

Question 2.
Write two slogans on solid waste management.
Answer:

1. Convert waste to wealth
   Don’t convert wealth to waste.
2. Recycle waste solid today
   for a better solid future.
3. Reuse, Reduce, Recycle
   The good, The bettel, the best

Question 3.
Draw and explain the diagram of Universal redyeing symbol.
(OR)
Draw “Universal Recycling Symbol”.
Answer:
When the number is omitted from recycling icon then it is known as Universal recycling symbol.

Question 4.
Nylon is a synthetic fibre. Write the advantages and disadvantages of it.
Answer:
Advantages of nylon as fibre:

1. Nylon fibre is strong, elastic and light weight.
2. Cloth made of nylon are lustrous and easy to wash.
3. Nylon does not absorb water.

Disadvantages of nylon as fibre:

1. Synthetic fibres cannot absorb moisture, thus they cannot be used as dress materials during summer.
2. They are dangerous to be worn near fire or heat as they catch fire easily.
3. They cannot be easily ironed.

Question 5.
Though there are so many harmful effects of plastic, we still prefer to use it. What could be its major advantages?
Answer:
Plastics are used in milk and oil pouches, containers to store pickles and rice, buckets to store water, chairs, water pipes, electrical, appliances, television, radio and computers and mobile phones.
Bakelite is used for making handles of various utensils due to its poor conductivity of heat and electricity.

Question 6.
Using an experiment explain how synthetic fibres are stronger than cotton fibres.
Answer:

1. Take an iron stand with a clamp.
2. Take cotton thread and synthetic threads like nylon about 50 cm in length.
3. Tie the cotton thread to the stand, so that it hangs freely from it.
4. At the free and attach a pan, so that a weight can be placed on it.
5. Add weight starting from 10 grams one by one, till the thread breaks down.
6. Note the total weight required to break the thread.
7. Repeat the same activity with synthetic thread also.
8. We can observe that more weights are required to break the synthetic thread than cotton thread.
9. Conclusion: Synthetic threads are stronger than cotton threads.

Question 7.

Answer the following questions.
i) Name the recyclabel material / materials.
ii) Name the thermosetting plastic articles.
iii) Which are thermoplastics but not to be recycled?
iv) Which are recycled but not thermosetting plastics?
Answer:
i) P.E.T bottles
ii) Electric switch, computer keyboard
iii) Polythene bag
iv) P.E.T bottle

Question 8.
Observe the following table.

Answer the following questions.
i. P.E.T is not used in the manufacture of cooker handles. Why?
ii. Which substance is used to manufacture electric switches? Why?
iii. Which is thermo plastic that can not be recycled?
iv. Why we have to ban the polythene covers?
Answer:
i) P.E.T is not used in the manufacture of cooker handles, because it is not a thermosetting plastic.
ii) Bakelite is used to manufacture electric switches, because it is thermosetting plastic.
iii) Polythene and PVC are thermoplastics that cannot be recycled.
iv) Polythene covers cannot be recycled. So, we have to ban the polythene covers.

Question 9.
Based on the smell given in the table identify the fibre and complete the table.

Smell on burning	Name of the fibre
If it smells like burning hair
If it smells like burning paper
If the yarn melts

Answer:

Smell on burning	Name of the fibre
If it smells like burning hair	Wool (or) Silk
If it smells like burning paper	Cotton
If the yarn melts	Polyester (or) nylon

Question 10.
Explain biodegradable and non-biodegradable materials with examples. Include their impact on environment.
Answer:

1. A material which is easily decomposed by natural process is called bio degradable, eg : Peels of fruits, papers, wood, cotton bags, etc.
2. A material which is not decomposed by natural process is called non-bio degradable, eg: Plastic
3. Impact on environment: Slow decomposition causes environmental pollution. The burning process of synthetic materials is also pollute the environment. This pollution causes health problems to the living things.

 

AP State Syllabus AP Board 8th Class Physical Science Important Questions Chapter 6 Sound

AP State Syllabus 8th Class Physical Science Important Questions 6th Lesson Sound

8th Class Physical Science 6th Lesson Sound 1 Mark Important Questions and Answers

Question 1.
What is sound? How does sound produces?
Answer:
Sound is a form of energy. A vibrating body produces sound.

Question 2.
Honeybee produce peculiar sound through their mouth or some other organ used for that purpose?
Answer:
A honeybee can’t make a sound using vocal cords. The buzzing sound that you b*ear from any flying insect is caused by vibration of their wings when flying.

Question 3.
Length of vocal cords in men is nearly 20 mm, in women it is about 5 cir1 less. Whereas in children it is shorter. Can we say that the length of vocal cords plays any role in deciding the quality of sound produced by men, women and children?
Answer:
Yes, we can say that the length of vocal cords decreases then the shrillness °f sound increases.

Question 4.
Pitch of the voices of the following is in ascending order. Lion < adult man < adult woman < child < infant < insect. Can you guess the reason why?
Answer:
The pitch of the voices depend on frequency. As the number of vibrations per second increases the pitch or shrillness increases. So insect produce shrillness due to more frequency of vibration.

Question 5.
Do you find any difference in blowing the whistle and striking the drum?
Answer:
Whistle has more shrillness due to its higher frequency than drum which has less frequency.

Question 6.
Why are some sounds loud?
Answer:
The sounds which have greater amplitude are louder.

Question 7.
Why are some sounds feeble?
Answer:
The sounds which have low amplitude are feeble.

Question 8.
Is there any relation between the intensity of sound and vibrations of the body which produces sound?
Answer:
As amplitude of vibration increases the intensity of sound increases.

Question 9.
How many times is a car horn more powerful than near total silence?
Answer:
It is 10¹¹ times more powerful than a near total silence.

Question 10.
How many times is a jet engine more powerful than a smallest audible sound?
Answer:
It is 10¹² times more powerful than a smallest audible sound.

Question 11.
What is a vibration?
Answer:
The to and fro motion of a body from its mean position is known as vibration.

Question 12.
What is amplitude?
Answer:
The maximum displacement of vibrating body from its mean position is called amplitude.

Question 13.
What are the parts of the speech organ which involved in producing sounds?
Answer:

1. Vocal cords
2. Lips
3. Teeth and tongue
4. Nose and throat

Question 14.
What is a music?
Answer:
Music is a combination of sounds that are produced in an order and pleasant to hear.

Question 15.
What is a noise?
Answer:
The sounds which are not pleasant to hear is called a noise.

Question 16.
What is pitch?
Answer:
The shrillness of a sound is known as pitch.

Question 17.
What is frequency?
Answer:
The number of vibrations per second is called frequency.

Question 18.
What is audible sounds? What is audible range?
Answer:
The sounds that a normal human being can hear is called audible sounds. Frequency of audible sound ranges from 20 cycles / second to 20000 cycles / second.

Question 19.
Do we hear the sounds produced by bats?
Answer:
We cannot hear sounds produced by bats because the sounds produced by bats have frequency more than 20,000 cycles / seconds that is more than audible range.

Question 20.
Does the sound travel if there is no medium?
Answer:
Sound required medium for its propagation. So sound does not travel if there is no medium i.e vacuum.

Question 21.
A bird makes high pitch sound and a lion makes a low pitch roar. Which one produce sound of more frequency?
Answer:
The bird produces sound of more frequency because it has high frequnecy as we already know pitch depends upon frequency.

Question 22.
Why do we produce sounds with different pitches or amplitudes while speaking?
Answer:
The vibration in pitch and amplitude of sound during our speech helps us to communicate with others in form of language.

Question 23.
Lightning and thunder take place in the sky at the same time at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain why?
Answer:
The speed of light is more than speed of sound so light travels faster. So we can see lightning first then we can hear thunder.

Question 24.
How intensity of sound related to its unit?
Answer:
The smallest audible sound (nearer to total silence) is 0 dB. A sound 10 times more powerful is 10 dB. A sound 100 times more powerful that of total silence is 20 dB. A sound 1000 times more powerful than sound nearer to silence is 30 dB.

Question 25.
How many times is a jet engine more powerful than the whispering sound?
Answer:
The decibel rating of jet engine = 120 dB
The decibel rating of whisper = 20 dB (for practical purpose)
The number of times a jet engine more powerful than a whisper = 10¹⁰ times
{120 – 20 = 100 that is taken as 10¹⁰}

Question 26.
How do you feel when you hear sounds in busy traffic?
Answer:
It is very unpleasant to hear.

Question 27.
How do you feel while listening to songs from a radio?
Answer:
It is very pleasant to hear.

Question 28.
Which of the above sounds are more pleasant to hear?
Answer:
Songs from radio are more pleasant to hear.

Question 29.
What is the unit to measure the sound intensity?
Answer:
Decibel is the unit for measuring the intensity of sound. It is denoted as dB.

8th Class Physical Science 6th Lesson Sound 2 Marks Important Questions and Answers

Question 1.
What is sound pollution? What are the causes of sound pollution?
Answer:
The unwanted sound in our surroundings is called sound pollution.
Causes of sound pollution:

1. Sounds of traffic
2. Sounds by motor bikes and their horns
3. Sounds in construction sites
4. Sounds at industries
5. Sounds at mines
6. Sounds during explosions and bursting of crackers
7. Sounds from mixer/grinder, washing machines and motors, etc.

Question 2.
Write some common sounds and their decibel ratings.
Answer:
Near total silence – 0 dB
A whisper – 15 dB
Normal conversation – 60 dB
A lawn mower – 90 dB
A car horn – 110 dB
A jet engine – 120 dB
A gun shot or fire cracker – 140 dB

Question 3.
How many times is a car horn more powerful than normal conversation?
Answer:
The decibel rating of car horn = 110 dB
The decibel rating of normal conversation = 60 dB
The number of times a car horn more powerful than normal conversation = 10⁵ times
{110 – 60 = 50 which is taken as 10⁵} (The explanation beyond our syllabus. It is based on logarithms)

Question 4.
How can you explain the sound has energy?
Answer:
Sound has energy: Take a plastic bottle and a cell phone.

Cut the top of the bottle so that it looks like a glass. Play songs on the mobile phone in high volume and place it in the bottle. Close the mouth of bottle with a balloon using rubber band so that it covers the bottle as shown in the figure and stretch it tightly so as to behave like a diaphragm. Place some sugar crystals or small sand particles on the balloon diaphragm and observe the movement of particles. Do the same activity after removing the phone from the bottle. Sound has energy

Question 5.
What are the differences between the noise and music? Explain.
Answer:

Noise	Music
1. Sounds which are not pleasant to hear are called Noise.	1. Sounds which are pleasant to hear are called Music.
2. Noise is an irregular combination of sounds.	2. Music is a combination of sounds. Which are produced in order.
3. It is unpleasant to hear.	3. It is pleasant to hear.

Question 6.
Explain the sources which produce sound pollution in your surroundings.
Answer:
Sources of sounds that are produce to sound pollution:

1. Sounds in traffic
2. Sounds by motor vehicles
3. Sounds in construction sites
4. Sounds in industries
5. Sounds in mines
6. Sources of sound pollution like mixer, grinder, washing machines and motors, etc.

Question 7.
What is the effect of humidity on quality of sound propagation? Is there any difference in propagation of sound in air during the summer and winter seasons? Discuss.
Answer:
With increase in humidity, density of air decreases. So with rise in humidity velocity of sound increases.
This is why sound travels in humid air (rainy season or winter) than in dry air (summer) at the same temperature.

Question 8.
Why the voice of men, women and children are different?
Answer:
The vocal cords of men about 20 mm long. In women these cords are about 5 mm shorter in respect to men. Children have very short vocal cords. That is the reason that voice of men, women and children are different.

Question 9.
On which property of vibrations does the loudness of sound depend?
Answer:
The loudness of sound is determined by its amplitude. When the amplitude of a vibration is large, the sound produced is loud. When the amplitude is small, the sound produced is feeble.

Question 10.
What are the harmful effects of noise pollution?
Answer:

1. Presence of excessive noise in the surroundings may cause many health related problems.
2. Lack of sleep, hypertension (high blood pressure), anxiety and many more health disorder may be caused by noise pollution. A person who is exposed to a loud sound continuously may get temperory or even permanent deafness.

Question 11.
What is the effect of humidity on quality of sound propagation? Is there any difference in propagation of sound in air during the summer and winter seasons? Discuss.
Answer:
In the winter season the air has fogs and behaves as liquid medium. So, the air moves little faster in it. Whereas in the summer the air is dried and no possibility of droplets. Hence the sound moves slower.
The propagation of sound is Solids > liquids > gases

Question 12.
Define audible sounds and inaudible sounds.
Answer:
Audible sounds:
The sounds that a normal human being can listen are called audible sounds. Frequency range is 20 cycles/sec – 20000 cycles/sec.
Inaudible sounds:
The sounds that a normal human being can’t listen are called inaudible sounds. Frequency range is less than 20 cycles/sec. or greater than 20000 cycles/sec.

8th Class Physical Science 6th Lesson Sound 4 Marks Important Questions and Answers

Question 1.
Describe structure of larynx or voice box.
Answer:
Larynx is the important organ in human body to produce sound. It has two muscular ligaments at the end of wind pipe called vocal cords. They are stretched across voice box, it leads to a narrow slit between them, to allow passage of air.

Vocal cords open during breathing to allow air into lungs. Vocal cords close when we speak.
The air from the lungs presses between them to use vibration and produce sound.

Question 2.
Draw anatomy of the larynx and label its parts.
Answer:

Question 3.
Draw the figures of using three musical instruments in your surroundings.
Answer:

Question 4.
a) Can sound travel in vacuum? Explain.
b) In which medium sound travels much faster and slower? Give some examples.
Answer:
a) Sound can’t travel in vacuum as it needs particles for propagation. As vacuum is empty, it is not possible.
b) Sound travels much faster in solids as the particles in solids are very closely packed, e.g.: Sound travels in train tracks (Railway tracks).
Sound travels much slower in gases as the particles in gases (air) are very loosely packed.
e.g.: Thunder or sound produced from amplifier at a long distance is feeble to hear.

Question 5.
Which object is vibrating when the following sounds are produced?
i) The sound of sitar or veena
ii) The sound of tabla
iii) The buzzing of bee or a mosquito
iv) The sound of a school bell
v) The sound of bursting balloon
vi) The radio
Answer:
i) Strings of sitar or veena vibrate to produce sound.
ii) The skin of the tabla vibrate to produce sound.
iii) Wings of mosquito or a bee vibrate to produce sound.
iv) The disc of the bell when beated with hammer vibrate to produce sound.
v) Air vibrates to produce sound.
vi) In the radio speakers vibrate to produce sound.

Question 6.
On which property of vibrations determines the pitch of the sound? Explain with examples.
Answer:

1. The frequency determines the shrillness or pitch of sound.
2. If the frequency of vibration is higher we say that the sound has a higher pitch.
3. If the frequency of vibration is lower, we say that the sound has a lower pitch. For example, the drum vibrates with a low frequency. Therefore, it produces a low pitched sound:
4. On the other hand, a wristle has a higher frequency, and therefore produces a sound of higher pitch.
5. A bird makes a high pitched sound whereas a lion makes a low pitch roar.

Question 7.
How can the noise pollution be controlled in a residential area?
Answer:

1. The noisy operations must be conducted away from any residential area.
2. Noise producing industries should be set up away from such areas.
3. Use of automobile horns are minimized.
4. T.V and music systems should be run at lower volumes.
5. Plants must be planted along the roads and around buildings to minimize the harmful effects of noise pollution.

Question 8.
What is the audiable range of frequencies for human beings? Explain.
Answer:

1. Sound of frequencies less than about 20 vibrations per second (20 Hz) cannot be detected by the human ear.
2. Such sounds are called inaudible.
3. On the other side, sound of frequencies more than about 20,000 vibrations per second (20,000 Hz) are also not audible to the human ears.
4. Thus for human ears, the range of audible frequencies is roughly between 20 to 20,000 Hz.

Question 9.
What is eardrum? How does it play an important role in hearings?
Answer:

1. We hear sound through our ears.
2. The shape of the outer part of ear is like a funnel.
3. When sound enters in it, it travels down a canal at the end of which a thin membrane is stritched tightly.
4. It is called the eardrum.
5. It performs an important function.

8th Class Physical Science 6th Lesson Sound Important Questions and Answers

Question 1.
Majority of communication in human beings is through speech. Name the organs which give human beings the ability to talk.
Answer:

1. Vocal cords
2. Lips
3. Teeth and tongue
4. Nose and throat

Question 2.
Why our steps do not produce sound if we walk on a carpet floor?
Answer:
Carpets are soft and as we know soft materials are bad conductors of sound. Thus the
carpet tends to absorb the sound produced. Also when we walk on the carpet the amplitude and vibrations of the floor is reduced leading to a lesser sound.

Question 3.
Sound does NOT travel in vacuum. Explain why.
Answer:

1. Sound energy travels in the form of wave.
2. To produce waves medium is required.
3. Hence, if there is no medium, sound waves cannot form.

Question 4.
Complete the following table.

Vibrating part of instrument	Name of the instrument
Stretched membrane
Stretched string

Answer:

Vibrating part of instrument	Name of the instrument
Stretched membrane	Tabala, Dappu, Mrudangam
Stretched string	Veena, Guitar, Violin

Question 5.
Mention the sounds which are responsible for sound pollution. Suggest four controlling measures of sound pollution.
Answer:
Causes of sound pollution:

1. Sounds of traffic
2. Sounds by motor bikes and their horns
3. Sounds in construction sites
4. Sounds at industries
5. Sounds at mines
6. Sounds during explosions and bursting of crackers
7. Sounds from mixer / grinder, washing machines and motors etc.

The steps to reduce sound pollution :

1. Attach silencers to the bikes and other machines to reduce sound.
2. Manufacture machines that work with lesser noise.
3. During the use of TVs and taperecorders tune down volume of sound.
4. Plant trees to reduce sound pollution.

Question 6.
What is sound pollution? Write effects of sound pollution. Suggest some measures to control sould pollution.
Answer:
The unwanted sound in our surroundings is called sound pollution.
Effects of sound pollution on bio-diversity:

1. The first harmful effect is loss of hearing.
2. It also leads to several health related problems, e.g : Sleeplessness, hypertension, increase in blood pressure, etc.
3. It effects the mental health of people.
4. In animals, noise can increase the risk of death by altering predator or prey detection and avoidance, interfere with reproduction and navigation and contribute to permanent hearing loss.
5. Noise pollution causes poor quality of crops.
6. Under water animals such as whales and dolphins too experience discomfort due to noise pollution caused by submarines, shipping companies and sonars. Cuttle fish and octopus suffer serious damage from noise pollution.

The steps to reduce sound pollution :

1. Attach silencers to the bikes and other machines to reduce sound.
2. Manufacture machines that work with lesser noise.
3. During the use of TVs and taperecorders tune down volume of sound.
4. Plant trees to reduce sound pollution.

Question 7.
Kushwanth said “Vibrating objects produce sound.” Establish that the given statement is true with relevant example from your surroundings.
Answer:
The statement given by Kushwanth is correct.
That is “vibrating objects produce sound”.
1. Eg: 1) If we ring the bell in the school, sound will produce.
2) If we touch the bell while ringing, vibrations will experience.

2. Eg: 1) We can observe sound coming from the engine of a vehicle.
2) This is due to vibration of the engine.

3. Eg: 1) Musical instruments vibrates and produce sound.
2) If we pull the string of a veena or guitar.
3) It will produce sound.

Question 8.
Based on the below information answer the following questions.

Musical Instrument	Vibrating part producing sounds
Veena	Stretchings string
Tabla	Stretched membrane
Flute	Air Column
Dholak	Stretched membrane
Sitar	Stretching string
Drum	Stretched membrane

a) Name the instruments which have vibrating part like a thin elastic rubber band.
Answer:
Tabla, Dholak, Drum.

b) What are the vibrating particles in the air column?
Answer:
Air particles.

c) What is the difference between Tabla and Sitar in terms of how they produce sound?
Answer:
In Tabla, stretched membrane vibrates and produce sound. Whereas in Sitar stretching string vibrates and produce sound.

d) How to produce different frequencies using a flute?
Answer:
By closing holes of the flute with fingers (or) By changing length of the air column.

Question 9.
Write about the propagation of sound in different media.
Answer:

1. Sound produced by source travels in a medium in the form of waves.
2. Vibrations produced by source of sound travel by particles of medium.
3. In the case of solids, particles of solid substance vibrates and travel along the substance.
4. In the case liquids, molecules of liquids carry the vibrations for sound propagation.
5. In the case of gas, gaseous molecules act as carries of vibrations and allow the sound propagation.

Question 10.
Explain the structure and functions of the ear using a diagram.
(OR)
Describe briefly about structure and functioning of the eardrum.
Answer:
Our ear consists of three sections, the outer ear, the middle ear and the inner ear, Pinna of external ear collects the sound vibrations. They enter into the ear canal. We have learnt that sound travels in the form of vibrations: These vibrations strike the tympanum (eardrum) and make it to vibrate.

The vibrations from the tympanic membrane reach the middle ear (ear ossicles), contains three small bones malleus (hammer shaped), incus (anvil shaped) and stapes (stirrup shaped). They magnify the sound vibrations.
The stapes transmits the vibrations to the membrane of oval window. The oval window has the surface area 1/20th of the ear-drum. By this the vibrations increase 30 to 60 times. The vibrations from the oval window transmit to the cochlea which is the inner part of the ear. The cochlea is filled with fluid which transmits the vibrations. The motion of the vibrations in the cochlea is detected by tiny hairs connected to nerves at this point. The vibrations are transformed into electrical signals and carried by the nerves to the brain where the sensation of the sound is realized.

Andhra Pradesh SCERT AP State Board Syllabus 6th Class Social Studies Study Material Guide Pdf free download, AP Board 6th Class Social Studies Textbook Solutions in English Medium and Telugu Medium are part of AP Board 6th Class Textbook Solutions.

Students can also go through AP Board 6th Class Social Notes to understand and remember the concepts easily. Students can also read AP 6th Class Social Important Questions for exam preparation.

AP State Syllabus 6th Class Social Studies Guide Study Material Pdf Free Download

6th Class Social Guide | AP State 6th Class Social Textbook Solutions

AP 6th Class Social Study Material Pdf English Medium

• Chapter 1 Our Earth in the Solar System
• Chapter 2 Globe – Model of the Earth
• Chapter 3 Maps
• Chapter 4 Land Forms – Andhra Pradesh
• Chapter 5 Early Life to Settled Life
• Chapter 6 Early Civilisations
• Chapter 7 Emergence of Kingdoms and Republics
• Chapter 8 Kingdoms and Empires
• Chapter 9 Government
• Chapter 10 Local Self-Government
• Chapter 11 Indian Culture, Languages and Religions
• Chapter 12 Towards Equality

AP Board 6th Class Social Studies Solutions Telugu Medium

• Chapter 1 సౌర కుటుంబంలో మన భూమి
• Chapter 2 గ్లోబు – భూమికి నమూనా
• Chapter 3 పటములు
• Chapter 4 ఆంధ్రప్రదేశ్ – భూస్వరూపాలు
• Chapter 5 సంచార జీవనం నుండి స్థిర జీవనం
• Chapter 6 తొలి నాగరికతలు
• Chapter 7 సామ్రాజ్యాలు, గణతంత్రాల ఆవిర్భావం
• Chapter 8 రాజ్యాలు మరియు సామ్రాజ్యాలు
• Chapter 9 ప్రభుత్వం
• Chapter 10 స్థానిక స్వపరిపాలన
• Chapter 11 భారతీయ సంస్కృతి, భాషలు మరియు మతాలు
• Chapter 12 సమానత్వం వైపు