100 INTERESTING SCIENCE FACTS

100 INTERESTING SCIENCE FACTS

1. The speed of light is generally rounded down to 186,000 miles per second. In exact terms it is 299,792,458 m/s (metres per second – that is equal to 186,287.49 miles per second).

2. It takes 8 minutes 17 seconds for light to travel from the Sun’s surface to the Earth.

3. October 12th, 1999 was declared “The Day of Six Billion” based on United Nations projections.

4. 10 percent of all human beings ever born are alive at this very moment.

5. The Earth spins at 1,000 mph but it travels through space at an incredible 67,000 mph.

6. Every year over one million earthquakes shake the Earth.

7. When Krakatoa erupted in 1883, its force was so great it could be heard 4,800 kilometres away in Australia.

8. The largest ever hailstone weighed over 1kg and fell in Bangladesh in 1986.

9. Every second around 100 lightning bolts strike the Earth.

10. Every year lightning kills 1000 people.

11. In October 1999 an Iceberg the size of London broke free from the Antarctic ice shelf .

12. If you could drive your car straight up you would arrive in space in just over an hour.

13. Human tapeworms can grow up to 22.9m.

14. The Earth is 4.56 billion years old…the same age as the Moon and the Sun.

15. The dinosaurs became extinct before the Rockies or the Alps were formed.

16. Female black widow spiders eat their males after mating.

17. When a flea jumps, the rate of acceleration is 20 times that of the space shuttle during launch.

18. ——-

19. If our Sun were just inch in diameter, the nearest star would be 445 miles away.

20. The Australian billygoat plum contains 100 times more vitamin C than an orange.

21. Astronauts cannot belch – there is no gravity to separate liquid from gas in their stomachs.

22. The air at the summit of Mount Everest, 29,029 feet is only a third as thick as the air at sea level.

23. One million, million, million, million, millionth of a second after the Big Bang the Universe was the size of a …pea.

24. DNA was first discovered in 1869 by Swiss Friedrich Mieschler.

25. The molecular structure of DNA was first determined by Watson and Crick in 1953.

26. The first synthetic human chromosome was constructed by US scientists in 1997.

27. The thermometer was invented in 1607 by Galileo.

28. Englishman Roger Bacon invented the magnifying glass in 1250.

29. Alfred Nobel invented dynamite in 1866.

30. Wilhelm Rontgen won the first Nobel Prize for physics for discovering X-rays in 1895.

31. The tallest tree ever was an Australian eucalyptus – In 1872 it was measured at 435 feet tall.

32. Christian Barnard performed the first heart transplant in 1967 – the patient lived for 18 days.

33. The wingspan of a Boeing 747 is longer than the Wright brother’s first flight.

34. An electric eel can produce a shock of up to 650 volts.

35. ‘Wireless’ communications took a giant leap forward in 1962 with the launch of Telstar, the first satellite capable of relaying telephone and satellite TV signals.

36. The earliest wine makers lived in Egypt around 2300 BC.

37. The Ebola virus kills 4 out of every 5 humans it infects.

38. In 5 billion years the Sun will run out of fuel and turn into a Red Giant.

39. Giraffes often sleep for only 20 minutes in any 24 hours. They may sleep up to 2 hours (in spurts – not all at once), but this is rare. They never lie down.

40. A pig’s orgasm lasts for 30 minutes.

41. Without its lining of mucus your stomach would digest itself.

42. Humans have 46 chromosomes, peas have 14 and crayfish have 200.

43. There are 60,000 miles of blood vessels in the human body.

44. An individual blood cell takes about 60 seconds to make a complete circuit of the body.

45. Utopia ia a large, smooth lying area of Mars.

46. On the day that Alexander Graham Bell was buried the entire US telephone system was shut down for 1 minute in tribute.

47. The low frequency call of the humpback whale is the loudest noise made by a living creature.

48. The call of the humpback whale is louder than Concorde and can be heard from 500 miles away.

49. A quarter of the world’s plants are threatened with extinction by the year 2010.

50. Each person sheds 40lbs of skin in his or her lifetime.

51. At 15 inches the eyes of giant squids are the largest on the planet.

52. The largest galexies contain a million, million stars.

53. The Universe contains over 100 billion galaxies.

54. Wounds infested with maggots heal quickly and without spread of gangrene or other infection.

55. More germs are transferred shaking hands than kissing.

56. The longest glacier in Antarctica, the Almbert glacier, is 250 miles long and 40 miles wide.

57. The fastest speed a falling raindrop can hit you is 18mph.

58. A healthy person has 6,000 million, million, million haemoglobin molecules.

59. A salmon-rich, low cholesterol diet means that Inuits rarely suffer from heart disease.

60. Inbreeding causes 3 out of every 10 Dalmation dogs to suffer from hearing disability.

61. The world’s smallest winged insect, the Tanzanian parasitic wasp, is smaller than the eye of a housefly.

62. If the Sun were the size of a beach ball then Jupiter would be the size of a golf ball and the Earth would be as small as a pea.

63. It would take over an hour for a heavy object to sink 6.7 miles down to the deepest part of the ocean.

64. There are more living organisms on the skin of each human than there are humans on the surface of the earth.

65. The grey whale migrates 12,500 miles from the Artic to Mexico and back every year.

66. Each rubber molecule is made of 65,000 individual atoms.

67. Around a million, billion neutrinos from the Sun will pass through your body while you read this sentence.

68/…and now they are already past the Moon.

69. Quasars emit more energy than 100 giant galaxies.

70. Quasars are the most distant objects in the Universe.

71. The saturn V rocket which carried man to the Moon develops power equivalent to fifty 747 jumbo jets.

72. Koalas sleep an average of 22 hours a day, two hours more than the sloth.

73. Light would take .13 seconds to travel around the Earth.

74. Males produce one thousand sperm cells each second – 86 million each day.

75. Neutron stars are so dense that a teaspoonful would weigh more than all the people on Earth.

76. One in every 2000 babies is born with a tooth.

77. Every hour the Universe expands by a billion miles in all directions.

78. Somewhere in the flicker of a badly tuned TV set is the background radiation from the Big Bang.

79. Even travelling at the speed of light it would take 2 million years to reach the nearest large galaxy, Andromeda.

80. The temperature in Antarctica plummets as low as -35 degrees celsius.

81. At over 2000 kilometres long The Great Barrier Reef is the largest living structure on Earth.

82. A thimbleful of a neutron star would weigh over 100 million tons.

83. The risk of being struck by a falling meteorite for a human is one occurence every 9,300 years.

84. The driest inhabited place in the world is Aswan, Egypt where the annual average rainfall is .02 inches.

85. The deepest part of any ocean in the world is the Mariana trench in the Pacific with a depth of 35,797 feet.

86. The largest meteorite craters in the world are in Sudbury, Ontario, canada and in Vredefort, South Africa.

87. The largest desert in the world, the Sahara, is 3,500,000 square miles.

88. The largest dinosaur ever discovered was Seismosaurus who was over 100 feet long and weighed up to 80 tonnes.

89. The African Elephant gestates for 22 months.

90. The short-nosed Bandicoot has a gestation period of only 12 days.

91. The mortality rate if bitten by a Black Mamba snake is over 95%.

92. In the 14th century the Black Death killed 75,000,000 people. It was carried by fleas on the black rat.

93. A dog’s sense of smell is 1,000 times more sensitive than a humans.

94. A typical hurricane produces the nergy equivalent to 8,000 one megaton bombs.

95. 90% of those who die from hurricanes die from drowning.

96. To escape the Earth’s gravity a rocket need to travel at 7 miles a second.

97. If every star in the Milky Way was a grain of salt they would fill an Olympic sized swimming pool.

98. Microbial life can survive on the cooling rods of a nuclear reactor.

99. Micro-organisms have been brought back to life after being frozen in perma-frost for three million years.

100. Our oldest radio broadcasts of the 1930s have already travelled past 100,000 stars.

NCERT Solutions for Class 6 English Honeysuckle Prose Chapter 6 Who I Am

NCERT Solutions for Class 6 English Chapter 6 Who I Am

NCERT Solutions for Class 6 English Chapter 6 Who I Am

Working With the Text   (Page 73)

Answer the following questions.

Q1. Peter’s favourite day of the week is Sunday because_______
Ans. ……. on this day the whole family goes to see a film.

Q2. Nasir wants to learn___________________
Ans. … Fr.e art of collecting cotton seeds.                             ‘

Q3.Dolma believes that she can make a good Prime Minister because____
Ans. ……. she hopes to make things better for everyone, to have great scientists and doctors, good hospitals and roads and schools.

B.Write True or False against each of the following statements.

1.Peter is an only child. _________________________ .
2.When Serbjit gets angry he shouts at people. _____________________________
3.Nasir lives in the city. _________________________
4.Radha’s mother enjoys doing things with her. ____________________________
Ans. 1. False;                        2. False;                 3. False;                    4. True.

NCERT SolutionsMathsScienceSocialEnglishHindiSanskritRD Sharma

NCERT Solutions for Class 6 Science Chapter 1 Food Where Does It Come From

NCERT Solutions for Class 6 Science Chapter 1 Food Where Does It Come From

NCERT Solutions for Class 6 Science Chapter 1 Food Where Does It Come From

The topics and Sub Topics in Class 6 Science Chapter 1 Food Where Does It Come From:

Section Name Topic Name
1 Food: Where Does it Come From?
1.1 Food Variety
1.2 Food Materials and Sources
1.3 Plant Parts and Animal Products as Food
1.4 Plant parts as food
1.5 What do Animals Eat?

Class 6 Science Chapter 1 Textbook Questions Solved

Q. 1. Do you find that all living beings need the same kind of food?
Ans. No, all living beings do not need same kind of food.

Q.2. Name five plants and their parts that we eat.
Ans. The names of five plants and their parts that we eat are:
(i) Paddy: seeds
(ii) Wheat: seeds
(iii) Mustard plant: seeds and leaves
(iv) Brinjal plant: fruits
(v) Potato plant: stems

Q. 3. Match the items given in column A with those in column B.
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does It Come From Q3
Q. 4. Fill up the blanks with the words given:
herbivore, plant, milk, sugarcane, carnivore.
(a) Tiger is a__________ because it eats only meat.
(b) Deer eats only plant products and so is called______________ .
(c) Parrot eats only__________
(d) The_________ that we drink, which comes from cows, buffaloes and goats is
an animal product.
(e) We get sugar from___________ .
Ans. (a) carnivore                                   (b) herbivore                 (c) plant
(d) milk                                     (e) sugarcane

Extra Questions for Class 6 Science Chapter 1

Class 6 Science Chapter 1 VERY SHORT ANSWER TYPE QUESTIONS

Q. 1. Give two examples where two or more parts of a single plant are used as food.
Ans. Mustard — seeds and leaves,
Pumpkin — fruit and flowers.

Q.2. Name any one plant that grows in water and is eaten as food.
Ans. Lotus — Stem of lotus is eaten as food.

Q.3. Suggest any three ways you can think of to avoid wastage of food.
Ans. (i) Avoid leaving food uneaten in meals.
(ii) “Eat to live” and not “live to eat” — excess eating should be avoided.
(iii) Raw food like pulses, grains should be stored properly.

Q.4. Name two sugar producing plants.
Ans. (a) Sugarcane                                           (b) Sugarbeet.

Q.5. Name a non-green plant that we eat.
Ans. Mushroom.

Q.6. What do you call the habit of an individual to eat a particular type of food items commonly?
Ans. Food habit.

Q.7. Compare your food habits with food habits of your friend who lives in Tamil Nadu.
Ans. My food habit: Chapatti, pulses, lassi, rice, vegetables, mustard oil.
Food habit of my friend: Idli, dosa, sambhar, bara, rasam, upma and coconut oil, etc.

Q.8. What items are used to prepare cooked rice?
Ans. Raw rice and water.

Q.9. Study the ingredients of various food items. Do they have some common food ingredients?
Ans. Yes, they have some common ingredients like: water, salt and oil or ghee.

Q.10. What are the two common sources of most of the ingredients of food items?
Ans. (i) Plants                                                  (ii) Animals

Q.11. Name the three products each provided by plants and animals.
Ans. Plant products: Grains, cereals and vegetables.
Animal products: Milk, egg and meat.

Q.12. Name three edible (eatable) parts of plants.
Ans. (i) Roots                                        (ii) Fmits                                (iii) Leaves

Q.13. Which part of the plants do we eat generally?
Ans. We generally eat fruits of many plants.

Q. 14. Which type of seeds give more energy, sprouted seeds or normal seeds?
Ans. Sprouted seeds give more energy than normal seeds.

Q.15. What is honey? 
Ans. A sweet substance (liquid) prepared by bees from the riectar, i.e., sweet juice collected from flowers is called honey.

Q.16. Where would you place human beings on the basis of food that they eat?
Ans. Omnivores.

Class 6 Science Chapter 1 SHORT ANSWER TYPE QUESTIONS

Q.l. What is food?
Ans. The eatable substances eaten by humans and other animals to get energy for various activities for growth and development is called food.

Q.2. Why should we eat cooked food?
Ans. We should eat cooked food because by cooking we can kill harmful germs and make it germless. Cooked food can be easily digested and absorbed by our body. Cooking also improves the taste of food.

Q.3. Explain the importance of food for living organisms.
Ans. Importance of food is:
(i)  It provides energy to do various activities.
(ii) It helps in growth.
(iii) It helps to repair and replace damaged parts of the body.
(iv) It protects us from infections and diseases.

Q.4.  Explain the various sources of food items and ingredients with the help of examples.
Ans.  There are mainly two sources of ingredients of various food items:
(i) Plants: Plants provide us fruits, vegetables, pulses, grains, cereals, etc.
(ii) Animals: Animals provide us milk, eggs, meat etc.

Q.5. Define the term herbivores.
Ans. The animals which eat only plants or plant products are called herbivores. For example, cow, goat and buffalo.

Q.6. What are carnivores? Explain with examples.
Ans. The-animals which eat other animals are called carnivores. For example, lion and tiger. Carnivores generally eat herbivores and other carnivores.

Q.7. Define the term omnivores.
Ans. The animals which eat both the plants and animals are called omnivores. For example, cat, dog and human beings.

Class 6 Science Chapter 1 LONG ANSWER TYPE QUESTIONS

Q. 1. With the help of a flow chart show various contributors involved when we eat a chapatti.
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does It Come From LAQ Q1

Q.2. Make flow charts for the preparation of honey and ghee.
Ans. Preparation of honey:
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does It Come From LAQ Q2
Q. 3. Differentiate between herbivores, carnivores and omnivores. Give two examples of each
NCERT Solutions for Class 6 Science Chapter 1 Food Where Does It Come From LAQ Q3
Q. 4. (i) Name the different parts of a banana plant that are used as food.
(ii)  Animal food we get from water resources.
(iii) Four fruits which we eat as vegetables.
Ans. (i) Flower, fruit and stem of banana.
(ii) Fish, prawn, lobustar and crabes.
(iii) Fruits of tomato, brinjal, Ladyfinger (bhindi), cucumber (Loki).

NCERT Solutions

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric

Topics and Sub Topics in Class 6 Science Chapter 3 Fibre to Fabric:

Section Name Topic Name
3 Fibre to Fabric
3.1 Variety in Fabrics
3.2 Fibre
3.3 Some Plant Fibres
3.4 Spinning Cotton Yarn
3.5 Yarn to Fabric
3.6 History of clothing material

Class 6 Science Chapter 3 Textbook Questions Solved

Q.1. Classify the following fibres as natural or synthetic: nylon, wool, cotton, silk, polyester, jute.
Ans. Natural fibres: wool, cotton, jute, silk.
Synthetic fibres: nylon, polyester.

Q.2. State whether the following statements are ‘true’ or false’:
(a) Yam is made from fibres.
(b) Spinning is a process of making fibres.
(c) Jute is the outer covering of coconut.
(d) The process of removing seeds from cotton is called ginning.
(d) Weaving of yam makes a piece of fabric.
(e) Silk fibre is obtained from the stem of a plant.
(g) Polyester is a natural fibre.
Ans.
(a) True
(b) False
(c) False
(d) True
(e) True
(f) False
(g) False

Q.3. Fill in the blanks:
(a) Plant fibres are obtained from____________ and___________ .
(b) Animal fibres are___________ and___________ .
Ans.
(a) cotton plants, jute plants
(b) wool, silk

Q. 4. From which part of the plant cotton and jute are obtained?
Ans.
(i) Cotton – Cotton bolls (from the surface of cotton seeds) (fruit)
(ii) Jute – Stem

Q.5. Name two items that are made from coconut fibre.  
Ans.
(i) Ropes
(ii) Mats

Q.6. Explain the process of making yam from fibre.
Ans. Yarns are made up of thin strands called fibres. The process of making yam from fibres is called spinning. In this process, a mass of cotton wool are drawn out and twisted. This brings the fibres together to form yarn.

EXTRA QUESTIONS for Class 6 Science Chapter 3

Class 6 Science Chapter 3 VERY SHORT ANSWER TYPE QUESTIONS

Q.1. Name two varieties of cloth materials which are commonly used.
Ans. Cotton, silk/wool.

Q.2. What are fabrics?
Ans. Fabrics mean a woven material, textile or other materials resembling woven cloth.

Q.3. Name some fabrics in your surroundings.
Ans. Bed-sheets, blankets, curtains, table clothes, towels and dusters.

Q. 4.  Name the thing which is used to make fabric.
Ans. Yarns.

Q.5. What are yarns made of?
Ans. Yarns are made up of thin strands called fibres.

Q.6. How many types of fibres are there?                                                        ,
Ans. There are two types of fibres:
(i) Natural fibres
(ii) Synthetic fibres

Q.7. Name two natural fibres.
Ans. 
(i) Cotton
(ii) Jute

Q.8. Name two synthetic fibres.
Ans. 
(i) Polyester
(ii) Nylon

Q.9. What material you use for making wicks for oil lamps?
Ans. Cotton wool.

Q.10. Where does cotton wool come from.?
Ans. Cotton wool comes from cotton bolls.

Q.11. What are fruits of cotton plants called?
Ans. Cotton bolls.

Q.12. What type of soil is used to grow cotton plants?
Ans. Black soil.

Q.13. Define ginning of cotton.
Ans. The process of separating fibres from the seeds of cotton is called ginning of cotton.

Q.14. What is jute?
Ans. Jute is a fibre obtained from the stem of a jute plant.

Q.15. Name the states where jute plants are mainly grown in India.
Ans. West Bengal, Bihar and Assam.

Q.16. What is spinning?
Ans. The process of making yarns from fibres is called spinning.

Q.17. Name two hand-operated devices used for spinning.
Ans.
(i) Takli
(ii) Charkha

Q.18. How are fabrics prepared?
Ans. Fabrics are prepared from the yarns by weaving or knitting.

Q. 19. Name the process used to prepare fabrics from yams.
Ans. The processes which used to prepare fabrics are: (i) Weaving and (ii) Knitting.

Q.20. What is weaving?
Ans. The process of arranging two sets of yarns together to make a fabric is called weaving.

Q.21. What is knitting?
Ans. The process in which a single yarn is used to make a piece of fabric is called knitting.

Q.22. Name two methods of knitting.
Ans.
(i) By hands
(ii) By machines

Q.23. Where were the cotton and flax plants cultivated in ancient Egypt?
Ans. Cotton and flax plants were cultivated near the river Nile in ancient Egypt.

Q.24. Name some modem fabrics formed by unstitched piece of fabric. .
Ans. Saree, dhoti, lungi and turban.

Q.25. How are natural fibres better than synthetic fibres?
Ans. The natural fibre absorbs sweat, gives cooling effect and comfort in any season.

Q.26. Are all fibres produced by plants?
Ans. No.

Q.27. Cotton on burning gives paper burning smell and cotton is obtained from plants. Is paper also obtained from plants?
Ans. Yes, paper is also obtained from plants.

Class 6 Science Chapter 3 SHORT ANSWER TYPE QUESTIONS

Q.1. What do you observe when you are visiting a nearby tailoring shop?
Ans. In a tailoring shop we observe that there are many cuttings of fabrics left over after stitching. We see that some cuttings are of cotton, some are of silk or wool and some are of synthetic fibres.

Q.2. List the steps involved in the preparation of fabric.
Ans. The following steps are involved in the preparation of fabrics:
(i) Obtaining fibre,
(ii) Preparation of yarn from fibres by spinning,
(iii) When two sets of yarn are involved, yarns are woven on looms to make a fabric. When a single yam is used, the fabric is prepared by knitting.

Q.3. What are natural fibres? Explain with examples.
Ans. The fibres obtained from plants and animals are called natural fibres. For example, cotton from cotton bolls, jute from jute plant, silk from cocoon of silkworm and wool from hair of animals like sheep or goat.

Q.4. What are synthetic fibres?
Ans. The fibres which are made from chemical substances or which are not obtained from the plant and animal sources are called synthetic fibres. For example, polyester, nylon, and acrylic, etc.

Q.5. Explain how jute is obtained from the jute plant.
Ans. The jute plant is normally harvested at flowering stage. The stems of harvested plants are bundled and immersed in water for 10 to 15 days. The stems rot (the process is called retting) and fibres are separated by hand. These fibres are converted into yarns to make fabrics (Fig. 3.10).
NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric SAQ Q5

Q. 6. What are looms?
Ans. The devices on which weaving of fabrics takes place are called looms. The looms are either hand operated or power operated.

Q. 7. What happens when a yam from a tom sock is pulled?
Ans. When we pull a yarn from a torn sock then a single yarn, gets pulled out continuously as the fabric gets unravelled. Socks are made up of knitted fabrics from a single yam.

Q. 8. What were the materials used by people in ancient times in place of clothes?
Ans. It appears that in those days people used the bark and big leaves of trees or animal skin and furs in place of clothes.

Q. 9. What happened when people began to settle in agricultural communities?
Ans. When people began to settle in agricultural communities then they learnt to weave twigs and grass into mats and baskets. Vines, animal fleece or hair were twisted together into long strands. These strands were woven into fabrics.

Q. 10. When we bum wool why do we get the smell of hair bum?
Ans. Wool is obtained from the fleece (hair) of sheep, goat, yak etc. This is the reason why burning of wool resembles the burning of hair.

Q. 11. When we bum nylon, why we do not get the smell of burning paper or burning hair?
Ans. Nylon is a synthetic fibre made from chemicals. On burning nylon these chemicals don’t produce the smell of burning paper or hair which are natural substances.

Class 6 Science Chapter 3 LONG ANSWER TYPE QUESTIONS

Q.1. Describe the process of the formation of yam from cotton wool.
Ans. The cotton wool is obtained from cotton plants. The cotton plants are grown in fields. They are usually grown at the places having black soil and warm climate. The fmits of the cotton plants called cotton bolls are about the size of lemons. After maturing, the bolls burst open and seeds covered with cotton fibres can b,e seen. From the cotton bolls cotton is picked by hands. Fibres are then separated from the seeds by combing. This process is called ginning of cotton. It is done by hand or by machines. These fibres are then converted into yam.
NCERT Solutions for Class 6 Science Chapter 3 Fibre to Fabric LAQ Q1
Q.2. Describe the process of spinning and weaving.
Ans. Spinning: The process of making yarn from fibres is called spinning. In this process fibres from a mass of cotton wool are drawn out and twisted. By this fibres come together to form a yarn. Spinning can be done by hand, by takli and charkha. On a large scale, spinning is done with the help of machines.
Weaving: The process of arranging two sets of yarns together t6 make a fabric is called weaving. The process of weaving can be done on looms. The looms are either-hand operated or power operated.

NCERT Solutions

NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us

NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us

NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us

Topics and Sub Topics in Class 6 Science Chapter 6 Changes Around Us

Section Name Topic Name
6 Changes Around us
6.1 Can all changes always be reversed?
6.2 Could there be other ways to bring a change?

Class 6 Science Chapter 6 Textbook Questions Solved

1. To walk through a waterlogged area, you usually shorten the length of your dress by folding it. Can this change be reversed?
Ans: Yes, it can be reversed by unfolding the dress.

2. You accidentally dropped your favourite toy and broke it. This is a change you did not want. Can this change be reversed?
Ans: No, this change (breaking of toy) cannot be reversed.

3. Some changes are listed in the following table. For each change, write in the blank column, whether the change can be reversed or not.
NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us Q3

4. A drawing sheet changes when you draw a picture on it. Can you reverse this change?
Ans: No, we cannot get fresh drawing sheet once a picture is drawn on it with paint/ oil or water. However, we can reverse the change, if soft pencil is used to draw the picture.

5. Give examples to explain the difference between changes that can or cannot be reversed.
Ans: Examples of reversible and irreversible changes
NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us Q5

NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us Q5.1

6. A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
Ans: No, the change in POP cannot be reversed since it is a chemical change.

7. A bag of cement lying in the open gets wet due to rain during the night. The next day the sun shines brightly. Do you think the changes, which have occurred in the cement, could be reversed?
Ans. No, these are irreversible chemical changes.

EXTRA QUESTIONS for Class 6 Science Chapter 6

Class 6 Science Chapter 6 VERY SHORT ANSWER TYPE QUESTIONS

1. Give two examples of slow changes.
Ans:
(a) Growing of plants
(b) Ripening of fruits.

2. Give two examples of fast changes.
Ans:
(a) Blowing of balloon
(b) Rolling out roti from dough ball.

3. Give two examples of reversible changes.
Ans:
(a) Drying of wet clothes
(b) Heating of milk.

4: Give two examples of irreversible changes.
Ans:
(a) Milk to cheese
(b) Cooking of food.

5. Can you say deforestation is an irreversible or reversible change?
Ans: It is an irreversible change.

6. Does the size of the paper change after making an aeroplane by folding it or by cutting it?
Ans: Yes.

7. Can you change the shape of a eraser after erasing?
Ans: Yes.

8. Why does a blacksmith heat the metal rim to fix it on a cart wheel?
Ans: A blacksmith heats the metal rim to fix it onto a cart wheel because a metal rim is made slightly smaller. On heating, the rim expands and fits onto the wheel. Then on cooling, the rim contracts and fits tightly onto the wheel.

9. What are slow and fast changes? Give examples.
Ans: The changes which take place in a long period of time are called slow changes whereas that changes which take place in a short period of time are called fast changes.
Examples:
(a) Rusting of iron, formation of day and night, ripening of fruits, growing of trees are slow changes.
(b) Burning of paper, stretching of rubber band, blowing of balloons, bursting of crackers are fast changes.

10. Classify the following into slow and fast changes:
(i) Spinning of top
(ii) Formation of day and night
(iii) Formation of curd from milk
(iv) Change of season
(v) Making curd from milk by adding lemon juice.
Ans:
(i) Fast change
(ii) Slow change
(iii) Slow change
(iv) Slow change
(v) Fast change.

11. Classify the following as slow or fast change:
(i) Bearing of heart
(ii) Change of seasons
(iii) Burning of paper
(iv) Weathering of rocks
(v) Melting of wax
(vi) Cooking of food
(vii) Burning of wax
(viii) Melting of ice cream
(ix) Curding of milk
(x) Formation of day and night
Ans:
(i) Fast
(ii) Slow
(iii) Fast
(iv) Slow
(v) Fast
(vi) Slow
(vii) Fast
(viii) Fast
(ix) Slow
(x) Slow

12. Write some changes happening in our body.
Ans:
(a) Our nails grow
(b) Our hair grows
(c) We grow taller
(d) Our weight increases.

 13. Some common changes are given in Table 6.1. Which of these changes do you think can be reversed?
NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us VSAQ Q13

Class 6 Science Chapter 6 SHORT ANSWER TYPE QUESTIONS

1. What is a physical change? Explain with example.
Ans: The changes in which only physical properties of substances are changed and no new substance is formed is called physical change. It is a reversible change. Example: Boiling and freezing of water.
NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us SAQ Q1

2. What is a chemical change? Explain with example.
Ans: The changes in which new substance with new chemical properties are formed are called chemical changes.
Example: Reaction between washing soda and lemon juice in which C02 and other substances are formed.
NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us SAQ Q2

3. What happens when sugar is heated?
Ans: When sugar is heated continuously then a black powdery substance is formed. This is a chemical change.
NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us SAQ Q3

Class 6 Science Chapter 6 LONG ANSWER TYPE QUESTIONS

1. Explain how a metal rim slightly smaller than a wooden wheel can be fixed on it.
Ans: The metal rim is always made slightly smaller than the wooden wheel. The metal rim is heated. On heating, the rim expands and fit onto the wheel. Cold water is then poured over the rim. Due to cooling the metal rim contracts and fits tightly onto the wheel.
NCERT Solutions for Class 6 Science Chapter 6 Changes Around Us LAQ Q1
2. How does curd being set? Is this change reversible?
Ans: A small quantity of curd is added to warm milk. The milk is stirred and is set aside undisturbed for a few hours at a warm place. In a few hours, the milk changes into curd.
Curd formed from milk cannot be changed into milk again. So, this an irreversible (cannot be reversed) change.

NCERT Solutions

NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants

NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants

NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants

Topics and Sub Topics in Class 6 Science Chapter 7 Getting to Know Plants:

Section Name Topic Name
7 Getting to Know Plants
7.1 Herbs, Shrubs and Trees
7.2 Stem
7.3 Leaf
7.4 Root
7.5 Flower

Class 6 Science Chapter 7 Textbook Questions Solved

1. Correct the following statements and rewrite them in your notebook.
(a) Stem absorbs water and minerals from the soil.
(b) Leaves hold the plant upright.
(c) Roots conduct water to the leaves.
(d) The number of sepals and petals in a flower is always equal.
(e) If the sepals of a flower are joined together, its petals are also joined together,
(f) If the petals of a flower are joined together, then the pistil is joined to the petal.
Ans:
(a) Roots absorb water and minerals from the soil.
(b) Roots hold the plant upright.
(c) Stem conducts water to the leaves.
(d) The number of petals and sepals in a flower is usually equal.
(e) If the sepals of a flower are joined together, its petals are not necessarily joined together.
(f) If the petals of a flower are joined together, then the pistil is not necessarily joined to the petal.

 2. Draw (a) a leaf, (b) a tap root and (c) a flower, you have studied for Table 7.3 of the textbook.
Ans:
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants Q2

NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants Q2.1

NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants Q2.2

3. Can you find a plant in your house or in your neighbourhood which has a long but a weak stem? Write its name. In which category would you classify it?
Ans: Yes, we find a money plant in our house. It is a climber.

4. What is the function of a stem in a plant?
Ans: A stem performs following functions:
(i) The stem and its branches hold leaves to get maximum sunlight.
(ii) It transports water from roots to different parts of the plant.
(iii) It transports food from leaves to different parts of the plant.
(iv) It bears leaves, flowers and fruits.

5. Which of the following leaves have reticulate venation?
Wheat, tulsi, maize, grass, coriander (dhania), china rose.
Ans: Tulsi, china rose.

6. If a plant has fibrous root, what type of venation are its leaves likely to have?
Ans: Parallel venation.

7. If a plant has leaves with reticulate venation, what kind of roots will it have?
Ans:Tap root.

8. Is it possible for you to recognise the leaves without seeing them? How?
Ans: We cannot exactly recognise the leaves without seeing them. We may be able to have some idea by touching and smelling them.

9. Write the names of the parts of a flower in sequence, from outside to inside.
Ans: The names of various parts of a flower from outside to inside are:
(i) Sepals
(ii) Petals
(iii) Stamens
(iv) Pistil

10. Which of the following plants have you seen? Of those that you have seen, which one have flowers?
Grass, maize, wheat, chilli, tomato, tulsi, pipal, shisham, banyan, mango, jamun, guava, pomegranate, papaya, banana, lemon, sugarcane, potato, groundnut
Ans:
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants Q10

11. Name the part of the plant which produces its food. Name this process.
Ans: Leaves produce food for the plant. This process is called photosynthesis.

12. In which part of a flower you are likely to find the ovary?
Ans: We find ovary in pistil. It is the lowermost part of the pistil.

13. Name two flowers, each with joined and separates sepals. 
Ans:
Flowers with joined sepals:
(i) Datura
(ii) Loki
Flowers with separate sepals:
(i) Gurhal
(ii) Mustard

EXTRA QUESTIONS for Class 6 Science Chapter 7 

Class 6 Science Chapter 7 VERY SHORT ANSWER TYPE QUESTIONS

1. List few plants found around your house.
Ans:  Mango, neem, grass, chilli, palak and banyan tree.

2. Are all the plants same in size?
Ans: No, all plants are of different sizes.

3. What are the major parts of plants?
Ans: Stem, root, leaves and flowers.

4. How many kinds of plants are there?
Ans: There are three kinds of plants:
(i) Herbs
(ii) Shrubs
(iii) Trees

5. Name two plants that belong to herbs.
Ans:
(i) Tomato
(ii) Potato

6. Give two examples of shrubs.
Ans:
(i) Lemon
(ii) Orange

7. Give two examples of trees.
Ans:
(i) Mango
(ii) Neem

8. Define petiole.
Ans: The part (stalk) of a leaf by which it is attached to the stem is called petiole.

9. What is lamina?
Ans:  The broad green flat part of leaf is called lamina.

10. What are veins?
Ans:  The lines on the leaf are called veins.

11. What is midrib?
Ans: A thick vein in the middle of the leaf is called midrib.

12. What is leaf venation?
Ans: The design made by veins in a leaf is called leaf venation.

13. How many types of leaf venation are there?
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants VSAQ Q13
Ans: There are two types of leaf venation:
(i)  Reticulate venation
(ii)   Parallel venation

14. What is transpiration?
Ans: The process by which water comes out from the leaves in the form of vapour is called transpiration.

15. Name the process by which leaves can prepare their food.
Ans: This process is called photosynthesis.

16. What are the raw materials for photosynthesis?
Ans:
(i)    Sunlight
(ii)  Water
(iii) Carbon dioxide
(iv)   Chlorophyll

17. Where does the photosynthesis take place in plants?
Ans: It takes place in the leaves.

18.  Name the part of plant which helps in holding the plant in the soil.
Ans: Roots.

19. Name the types of roots shown in the Fig. 7.7.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants VSAQ Q19
Ans: (i) Tap roots (ii) Fibrous roots

20. What are tap roots?
Ans: The roots in which one root is main root and other lateral roots grow on it are called tap roots.

21. Give names of two plants which have tap root.
Ans: Gram and mustard.

Q. 22. Name two plants which have fibrous root.
Ans: (i) Wheat plant         (ii) Maize plant

23. What are lateral roots?
Ans: The smaller roots that grow on the main tap root are called lateral roots.

24. What are fibrous roots?
Ans: The roots which do not have any main root but all the roots are similar are called fibrous root.

25. Does the stem prepare food for any plant?
Ans: Yes, there are some plants whose stem prepares food, e.g. cactus.

26. Name the prominent parts of a flower.
Ans: The prominent parts of a flower are petals, sepals, stamens and pistil.

27. What are sepals? What are their functions?
Ans: The small green coloured leaf-life structures are called sepals. It protects flower when it is in stage of bud.

28. What are petals? Why are they generally coloured?
Ans: The coloured big leaf-life structures present in flower are called petals. Petals are coloured so as to attract insects for pollination.

29. What are stamens?
Ans:When we remove sepals and petals from the flower then we see some filaments in the flower which are called stamens. These, are the male part of the flower.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants VSAQ Q29

30. Name various parts of stamen.
Ans: There are two parts of a stamen:
(i) Anther (ii) Filament.
These are the male part of the flowers.

31. What is pistil?
Ans: The innermost part of a flower is called pistil. These are the female part of the flowers.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants VSAQ Q31

32. Name the various parts of pistil.
Ans: There are three parts of pistil:
(i) Stigma              (ii) Style             (iii) Ovary

33. What are ovules?
Ans: These are small bead-like structures inside the ovaiy.

Class 6 Science Chapter 7 SHORT ANSWER TYPE QUESTIONS
1. What are weeds?
Ans: The unwanted plants that grow in the fields with the main crops or in their surroundings are called weeds. Weeds are the plants which are not grown by the farmers. For example, grass.

2. Classify plants and give an example of each.
Ans: On the basis of various characteristics most of the plants can be classified into three categories:
(i) Herbs, e.g. tomato
(ii) Shrubs, e.g. lemon
(iii) Trees, e.g. mango

3. What are herbs? Give two examples.
Ans: The plants with green and tender stems are called herbs. They are usually short and may have no or less branches. For example, tomato, potato.

4. What are shrubs? Give two examples.
Ans: The plants which have a hard but not a very thick stem are called shrubs. Such plants have the stem branching out near the base. For example, lemon, rose plants.

5. What are trees? Give two examples.
Ans: The plants which are very tall and have hard and thick brown stem are called trees. The stems have branches in upper part and much above the ground. For example, mango, neem.

6. What are creepers? Write an example.
Ans. The plants with weak stem that cannot stand upright and spread on the ground are called creepers. Various types of grasses are the examples of creepers.

7. What are climbers?
Ans: The plants that take support of neighbouring structures and climb up are called climbers. They have weak stem. For example, grapes, money plant, beans.

8. Explain an activity to show that stem conducts water and other substances.
Ans: Take some water in a glass. Add few drops of red ink to the water. Cut the stem of a herb plant from its base. Put it in the glass as shown in figure. We will see that some parts of the stem become red. This activity shows that stem conducts water.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants SAQ Q8

9. Explain the structure of a leaf with the help of a labelled diagram.
Ans: There are two main parts of leaf:
(i) Petiole: The part of the leaf by which it is attached to the stem is called petiole.
(ii) Lamina: The broad, green part of the leaf is called lamina.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants SAQ Q9
The lamina contains following parts:
(i) Veins: There are various types of lines on the leaf. These lines are called veins
(ii) Midrib: There is a thick vein in the middle of the leaf. This vein is called midrib.

10. Explain the main functions of leaf.
Ans: There are following two main functions of leaf:
(i) Transpiration: The extra water comes out of the leaves in the form of vapour. This process is called transpiration.
(ii) Photosynthesis: The process by which leaves prepare their food from water and carbon dioxide, in the presence of sunlight and a green-coloured substance, is called photosynthesis.

11. What are unisexual and bisexual flowers?
Ans: Unisexual flower has either male (stamen) or female (pistil) parts.
Bisexual flowers have both male and female whorl in the flowers, i.e., they have both stamen and pistil.

12. Name a plant that eats insect.
Ans: Pitcher plant.

13. Pitcher plant has green leaves which can prepare food by photosynthesis then why does it eat insects?
Ans: To get nitrogenous compounds which it cannot absorb from the soil.

14. Name a plant that has underground as well as aerial (above the ground) root system.
Ans: Banyan tree.

15. Why do we see dew drops on leaves in the early morning?
Ans: At night the water lost by leaves does not get evaporated and gets collected on the leaves in the form of dew drops.

16. Why are petals colourful?
Ans: The colourful petals attract insects for pollination.

17. Why does white flowers bloom at night?
Ans: White colour attracts night insects for pollination.

18. What do you mean by a complete and incomplete flower?
Ans: The flower with all whorls, i.e., sepals, petals, stamen and carpel in it is a complete flower. If any one of this is absent in a flower it is called an incomplete flower.

19. Leaves need oxygen and carbon-dioxide (for photosynthesis). How do they get these gases?
Ans: Leaves take in these gases from atmosphere through small pores present on them called stomata.

20. How can one destarch the leaves of potted plant without plucking, them?
Ans: By keeping it in dark for 2-3 days.

21. What is the relation between leaf venation and the type of roots?
Ans: The plants having tap root have reticulate venation. The plants having fibrous roots have parallel venation.

22. Name the male part of a flower. Write names of its parts and draw a diagram.
Ans: The male part of a flower is called stamen. It has two parts: (i) Filament and (ii) Anther.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants SAQ Q22

23.Name the female part of a flower. Write names of its parts and draw a diagram.
Ans:The female part of a flower is called pistil. It has three parts: (i) Stigma, (ii) Style, and (iii) Ovary.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants SAQ Q23

24. Differentiate between tap root and fibrous root.
Ans:
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants SAQ Q24

Class 6 Science Chapter 7 LONG ANSWER TYPE QUESTIONS

1. What do you mean by leaf venation? Explain various types of leaf venation with example.
Ans: Leaf venation: The design made by veins in a leaf is called leaf venation. There are the following two types of leaf venation:
(i) Reticulate venation: If the design of veins makes a net-like structure on both the sides of midrib then it is called reticulate venation. For example, mango leaf, gram leaf.
(ii) Parallel venation: If the veins are parallel to each other or to midrib then such type of venation is called parallel venation. For example, wheat leaf, barley leaf.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants LAQ Q1

2. Explain the structure of a typical flower with the help of a diagram.
Ans: A typical flower contains the following parts:
(i) Stalk: The part by which a flower is attached to the branch is called stalk.
(ii) Sepals: The small green leaf-like structures of the flower are called sepals,
(iii) Petals: The big coloured leaf-like structures are called petals. Different flowers have petals of different colours.
(iv) Stamen: It is the male part of the flower. It has two parts: (a) Filament and (b) Anther.
(v) Pistil: The innermost part of a flower is called pistil. It has three parts: (a) Stigma, (b) Style and (c) Ovary. It is the female part of the flower.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants LAQ Q2

3. Explain an activity to test the presence of starch in a leaf.
Ans: Take a leaf in a test tube and pour spirit till it completely covers the leaf. Now put the test tube in a beaker having water. Heat the beaker till all the green colour from the leaf comes out into the spirit in the test tube. Take out the leaf and wash it with water. Put it on a plate and pour some iodine solution over it. The iodine solution is brown in colour but when it comes in contact with starch it turns blue-black. The iodine solution will turn blue-black when dropped on the leaf, this confirms the presence of starch in the leaf.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants LAQ Q3

4. Explain that sunlight is essential for photosynthesis.
Ans: Take a potted plant having green leaves. Place it in a dark room for a day or two so that all the starch present in leaves is used by the plant. Now cover a portion of leaf with black paper and keep the plant in the sun for a day. Pluck the leaf, remove the black paper and test it for the starch. We see that only that part of the leaf becomes blue-black which was open to sun. The covered part does not become blue-black. This shows that no starch is formed because it gets no sunlight.

5. Explain the important functions of root.
Ans:. The following are the functions of root:
(i) They help to absorb water from the soil.
(ii) The roots help in holding the plants firmly in the soil.
(iii) They are said to anchor the plant to the soil.

6. Explain various kinds of roots with the help of an example.
Ans: There are following two types of roots:
(i) Tap roots: The roots which have one main root and other smaller lateral roots are called tap roots. For example, mustard plant, gram.
(ii) Fibrous roots: The roots which have no main root but all the roots appear similar are called fibrous roots. For example, maize, wheat.
NCERT Solutions for Class 6 Science Chapter 7 Getting to Know Plants LAQ Q6

NCERT Solutions

NCERT Solutions for Class 6 Science Chapter 8 Body Movements

NCERT Solutions for Class 6 Science Chapter 8 Body Movements

Topics and Sub Topics in Class 6 Science Chapter 8 Body Movements:

Section Name Topic Name
8 Body Movements
8.1 Human Body and Its Movements
8.2 Gait of Animals

1. Fill in the blanks:
(a) Joints of the bones help in the_____________ of the body.
(b) A combination of bones and cartilages forms the_______________ of the body.
(c) The bones at the elbow are joined by a______________
(d) The contraction of the____________ pulls the   bones  during  
Ans: 
(a) movement
(b) skeleton
(c) hinge
(d) muscle

2. Indicate ‘true’ and false’ among the following sentences:
(a) The movement and locomotion of all animals is exactly the same.
(b) The cartilages are harder than bones.
(c) The finger bones do not have joints.
(d) The fore arm has two bones.
(e) Cockroaches have an outer skeleton.
Ans: 
(a) False
(b) False
(c) False
(d) True
(e) True

3. Match the items in column I with one or more items of column II:

Column I   Column II
(i) Upper jaw (a) have fins on the body
(ii) Fish (b) has an outer skeleton
(iii) Ribs (c) can fly in the air
(iv) Snail (d) is an immovable joint
(v) Cockroach (e) protect the heart
(f) shows very slow movement
(g) have a streamlined body

Ans:
NCERT Solutions for Class 6 Science Chapter 8 Body Movements Q3

4. Answer the following questions:
(a) What is a ball and socket joint?
(b) Which of the skull bones are movable?
(c) Why can our elbow not move backwards?
Ans:
(a) The rounded end of one bone fits into the hollow space of other bone. This is called ball and socket joint. Ball and socket joints allow movements in all the directions, e.g. shoulder and hip can be moved in all directions.
(b) In skull, only lower jaw is movable.
(c) Our elbow cannot move backwards because the elbow has a hinge joint that allows movement in only one direction.

Class 6 Science Chapter 8 VERY SHORT ANSWER TYPE QUESTIONS

1. What do you mean by movement?
Ans:  The changing position of the body or any part of the body is called movement.

2. At which part does the arm rotate?
Ans: The arm rotates on the round pit-like structure.

3. If you tie a scale with your arm, are you able to bend your elbow?
Ans: No, we cannot bend our elbow.

4. Name the places where two parts of the body are seen to be joined together.
Ans: These places are called joint.

5. If there are no joints then will it be possible to move?
Ans: No, it is not possible.

6. Can bones be bent?
Ans:  No, bones cannot be bent.

7. Can we bend our body at every part?
Ans: No, we can bend our body only at joints.

8. How many types of joints are there?
Ans: There are five types of joints in our body.

9. Name the various types of joint.
Ans: 
(i) Ball and socket joints
(ii) Pivotal joints
(iii) Hinge joints
(iv) Fixed joints
(v) Gliding joints

10. What is cavity in bone?
Ans:  The hollow space in the bone is called cavity.

11. Give two examples of ball and socket joint.
Ans: 
(i) Joint of upper arm and shoulder.
(ii) Joint of thigh and the hip.

12. Give an example of pivotal joint.
Ans. The joint of skull with backbone.

13. Give two examples of hinge joints.
Ans:
(i) Joints in fingers
(ii) Joints in knee

14. Give an example of fixed joint.
Ans: Joint of cranium skull.

15. Give an example of gliding joint.
Ans: The joint in backbone.

16. What is skeleton?
Ans: The framework of bones in our body is called skeleton.

17. What are ribs?
Ans: The bones of the chest are called ribs.

18. What is rib cage?
Ans: Ribs are joined with backbone to form a box. This box is called rib cage.

19. What are shoulder bones?
Ans: The shoulder bones are formed by the collar bone and the shoulder blade. It connects the upper part of the chest and bones of the arm.

20. What are pelvic bones?
Ans: The bones which enclose the body part below the stomach are called pelvic bones.

21. What are cartilages?
Ans: Some additional parts of the skeleton which are not as hard as bones and are elastic in nature and can be bent are called cartilages, e.g. cartilage of ear.

22. Name the three components of skeleton.
Ans: Skeleton is made up of many bones, joints and cartilage.

23. Name the parts of the body which help in movement.
Ans: Contraction and relaxation of muscles and bones and joints help in movement.

24. Name two animals which move without bones.
Ans: (i) Earthworm      (ii) Snail

25. Give an example of animal which can walk, climb and fly in the air.
Ans: Cockroaches.

26. Name the organ in cockroach which helps in walking.
Ans: The three pairs of legs in cockroach help in walking.

27. Which part of the cockroach help in flying?
Ans: There are two pairs of wings attached to the breast which help them in flying.

28. Name a bird which can swim in water.
Ans. Duck.

29. What do you mean by streamlined?
Ans: If the body tapers at both the ends then such, shape of the body is said to be streamlined.

30.How does the snake move?
Ans: Snakes have a long backbone and many thin muscles which help in the movement. The snake’s body curves into many loops. Each loop of the snake gives it a forward push by pressing against the ground.

31. What do you mean by fractured bone? 
Ans: Fractured bone means broken bone.

32. Why are fractured bones plastered?
Ans. Plaster keeps broken bones at their right place so that they grow and join properly.

33. Name organs that are protected by the rib cage?
Ans: Heart and Lungs.

34. Why do we need two muscles together to move a bone?
Ans: A muscle can only pull, it cannot push. Thus, two muscles are required to work together to move a bone. When one muscle contracts, the bone is pulled. When another muscle of the pair pulls, it brings the bone in its original position.

35. Name three animals that have streamlined body.
Ans: Fish, Birds, Snake.

36. Many people suffer from a problem called arthritis. Explain its connection with movement.
Ans: Arthritis is the pain in joints. With this problem people find difficulty in moving from one place to another.

37. How is a bird’s body adapted for flying?
Ans: The following adaptations are seen in the body of birds.
(i) Bones are hollow.
(ii) Forelimbs are modified into wings.
(iii) Body is streamlined.

Class 6 Science Chapter 8 SHORT ANSWER TYPE QUESTIONS

1. What are joints? Write the names of various types of joints.
Ans: The places where two parts of the body seem to be joined together are called joints. There are following types of joints:

  1. Ball and socket joints
  2. Pivotal joints
  3. Hinge joints
  4. Fixed joints
  5. Gliding joints

2. What is skeleton? Draw a diagram to show the human skeleton.
Ans: The bones in our body form a framework to give a shape to the body. The framework is called skeleton
NCERT Solutions for Class 6 Science Chapter 8 Body Movements SAQ Q2

3. Write two ways by which we may know the shape of human skeleton.
Ans:
(i) We can know the shape of skeleton by feeling.
(ii) We could know the shape by X-ray images of human body

4:Write the differences between bones and cartilage.
Ans:  

Bone       Cartilage
(i) They are hard. (i) They are soft.
(ii) They cannot bend. (ii) They can bend.
(iii) They are used to make the framework of whole body. (iii) They help to make some parts of the body.

5. How do the muscles work?
Ans: The muscles work in pairs. When one of them contracts, the bone is pulled in that direction, the other muscle of the pair relaxes. To move the bone in the opposite direction, the relaxed muscle contracts to pull the bone towards its original position, while the first relaxes.A muscle can only pull. It cannot push.
NCERT Solutions for Class 6 Science Chapter 8 Body Movements SAQ Q5

6. How does the earthworm move?
Ans:  Earthworm does not have bones. It has muscles. During the movement, earthworm first extends front part of the body keeping the rear portion fixed to the ground. Then it fixes the front and releases the rear end. It then shortens the body and pulls the rear end forward. In this way by repeating such muscular expansions and contractions earthworm moves.
NCERT Solutions for Class 6 Science Chapter 8 Body Movements SAQ Q6

7. How does the snail move?
Ans: The rounded structure on the back of the snail is called shell. It is the outer skeleton (exoskeleton) of snail. When it starts moving a thick structure and the head of the snail may come out of an opening in the shell. The thick structure is called foot, which is made up of strong muscles. It helps snail in moving.
NCERT Solutions for Class 6 Science Chapter 8 Body Movements SAQ Q7

8. How does fish move in water?
Ans: The body of fish is streamlined. The streamlined shape helps the fish to move in water. The skeleton of fish is covered with muscles which make the front part of the body to curve to one side and the tail part swings towards the opposite side. This makes a jerk and pushes the body forward. In this way it moves in water.
NCERT Solutions for Class 6 Science Chapter 8 Body Movements SAQ Q8

Class 6 Science Chapter 8 LONG ANSWER TYPE QUESTIONS

1. Explain various kinds of joints found in our body and give example of each.
Ans: There are five types of joints in our body:
(i) Fixed joints: Those joints which do not allow movement are called fixed joint.
NCERT Solutions for Class 6 Science Chapter 8 Body Movements LAQ Q1
(ii) Ball and socket joint: This joint allows movement in all directions. The rounded end of one bone fits into the hollow space of other bone. For example, joint between upper arm and shoulder.
NCERT Solutions for Class 6 Science Chapter 8 Body Movements LAQ Q1.1
(iii) Pivotal joint: This type of joint allow movement in all planes, i.e. up and down, side and other planes. For example, head.
(iv) Hinge joint: The joint which allows movement only in one plane is called hinge joint. For example, fingers, knees.
NCERT Solutions for Class 6 Science Chapter 8 Body Movements LAQ Q1.2
(v) Gliding joint: These joints allow only a limited amount of movement of sliding nature of cartilage. For example, the joints of backbone.
NCERT Solutions for Class 6 Science Chapter 8 Body Movements LAQ Q1.3

NCERT Solutions

NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings

NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings

Topics and Sub Topics in Class 6 Science Chapter 9 The Living Organisms and Their Surroundings:

Section Name Topic Name
9 The Living Organisms Characteristics and Habitats
9.1 Organisms and The Surroundings Where They Live
9.2 Habitat and adaption
9.3 A journey through different habitats
9.4 Characteristics of  organisms

1. What is a habitat?
Ans: The surroundings where animals live is called their habitat. The organisms depend on their habitat for their food, water, air, shelter and other needs. Habitat means a dwelling place.

2. How are cactus adapted to survive in a desert?
Ans: Cactus are adapted to survive in a desert as they have
(i) No leaves or spiny leaves to prevent water loss through transpiration.
(ii) Stem is modified in such a way that it performs photosynthesis and conserves water.
(iii) Their roots go very deep into the soil for absorbing water.

3. Fill in the blanks:
(a) The presence of specific features which enables a plant or an animal to live in a particular habitat is called___________ .
(b) The habitats of the plants and animals that live on land are called _________________ habitats.
(c)The habitats of plants and animals that live in water are called ____________________ habitats.
(d) Soil, water and air are the____________ factors of a habitats.
(e) Changes in our surroundings that make us respond to them are called
Ans: 
(a) adaptation
(b) terrestrial
(c) aquatic
(d) abiotic
(e) stimuli

4. Which of the things in the following list are non-living?
Ans: Plough, Mushrooms, Sewing machine, Radio, Boat, Water, Hyacinth, Earthworm. Plough, Sewing machine, Radio, Boat and water are non-living.

5. Give an example of a non-living thing which shows any two characteristics of living thing.
Ans: Example of non-living thing is cloud which shows following two characteristics of living things:
(i) It grows in size
(ii) It shows movement.

6. Which of the following non-living things were once part of a living thing?
Butter, Leather, Soil, Wool, Electric Bulb, Cooking Oil, Salt, Apple, Rubber.
Ans: Butter, Leather, Wool, Cooking oil, Apple and Rubber are the non-living things which were once part of a living thing.

7. List the common characteristics of living things.
Ans: Some common characteristics of living things are:

  1. Growth
  2. Movement
  3. Reproduction
  4. Respiration
  5. Responsiveness
  6. Excretion

8. Explain why speed is important for survival in the grasslands for animals that live there. (Hint: There are few trees or places for animals to hide in grasslands habitats).
Ans: In grasslands habitats, there are few trees or places for animals to hide. When their enemy attacks they have to run faster so as to reach a safe place. If they fail, they lose their life. So, the speed is very important for survival of grassland animals.

Class 6 Science Chapter 9 VERY SHORT ANSWER TYPE QUESTIONS

1. Name some plants found on mountains.
Ans: Oaks, Pinus and Deodars.

2. What is habitat?
Ans:. The place where organisms live and which provide food and safety for them is ‘called habitat.

3. Name a few habitats.
Ans: Forests, grassland, mountains, ponds and oceans etc.

4. Name two organisms that live in deserts.
Ans:  Cactus, camel, desert rat.

5. Name a few plants that live in ponds.
Ans:  Hydrilla, lotus, hyacinth etc.

6. Name the habitat where various types of fish live.
Ans:  Pond, river, sea.

7. Name a common thing in all fishes.
Ans:  Gills, streamlined body, fins, tail.

8. What is the function of gill?
Ans: Gills help the fish to absorb oxygen dissolved in water.

9. Name the animal which is called the ship of desert.
Ans: Camel

10. Name various types of habitat.
Ans:
(i) Terrestrial Habitats
(ii) Aquatic Habitats
(iii) Aerial Habitat

11. Name two aquatic animals.
Ans:
(i) Fish
(ii) Tortoise

12. Name two terrestrial organisms.
Ans:
(i) Cat
(ii) Dog

13. Name two examples of aerial habitat animals.
Ans:
(i) Birds
(ii) Mosquitoes

14. Name the types of components of habitat.
Ans: Components of habitat are:
(i) Biotic components
(ii) Abiotic components

15. Give two examples of each biotic and abiotic components.
Ans: Plants and animals are biotic components, air and water are abiotic components.

16. What do you mean by germination of seeds?
Ans: The beginning of a new plant from the seeds is called germination.

17. Does adaptation take place in a short time?
Ans: No, adaptation does not take place in a short time. It takes place in thousands of years.

18. Name few terrestrial habitats.
Ans: Deserts, mountains and grassland.

19. Name some aquatic habitats.
Ans:Oceans, ponds and lakes.

20. What are predators?
Ans: The animals which kill other animals for their food are called predators.

21. What is a prey?
Ans: The animals which are killed by predators for their food are called prey.

22. Name two aquatic animals which have no gills.
Ans: Dolphin and whales.

23. What are blowholes?
Ans: The organs by which dolphin or whales breathe are called blowholes or nostrills.

24. What is photosynthesis?
Ans: The process by which plants make their own food with the help of chlorophyll,sunlight, carbon dioxide and water is called photosynthesis.

25.What is the main Junction of food?
Ans: Food gives energy to the organism which helps them in growth and development.

26. What is breathing?
Ans:  The process of taking in oxygen and giving out carbon-dioxide (inhalation and exhalation of air) is called breathing.

27. What is respiration?
Ans: The process in which oxygen is used by the living bodies to break down food to get energy, water and carbon dixode is produced is called respiration.

28. What is stimuli?
Ans: The changes in our surroundings that makes us respond to them are called stimuli.

29. What is excretion?
Ans: The process of getting rid of the waste by the living organisms is known as excretion.

30. Do plants also excrete?
Ans: Yes, plants also excrete.

31. What is reproduction?
Ans: The process by which living organisms produce more of their own kind is called reproduction.

32. Do animals move?
Ans: Yes, animals move from one place to another.

33. Do plants also move?
Ans:  Plants are generally fixed in the soil so they do not move from one place to another.

Class 6 Science Chapter 9 SHORT ANSWER TYPE QUESTIONS

1. What are the differences in the desert and sea regions?
Ans: In the sea, plants and animals are surrounded by salty water. Most of them use the air dissolved in water for breathing. In desert, a very little amount of water is available. It is very hot in the day time and very cold at night. The organisms breathe air from the surroundings.

2. What do you mean by term adaptation?
Ans: The presence of specific features or certain habits which enable a plant or an animal to live in its surroundings is called adaptation.

3. Explain the features offish which help it to adapt to live in water.
Ans:
(i) The shape of the fish is streamlined which help in the movement.
(ii) The slippery scales/skin on their bodies to protect them.
NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings SAQ Q3
(iii) They have flat fins and tails which help them to swim, change direction and to keep the body balanced.
(iv) They have gills which help in breathing in water.

4. How are camels adapted to live in desert?
Ans: (i) The feet of the camels have thick, flat large soles which help them in the movement on sand.
(ii) They can live without water for a long time. When water is available, it drinks large amount of water at a time.
(iii) They release very little urine to prevent loss of water.
(iv) Their dung is also dry which also helps to prevent loss of water.
(v) The long legs of camel helps to keep the body away from the heat of the sand.

5. What do you mean by acclimatisation?
Ans: The small changes which take place in the body of a single organism over short periods to overcome small problems due to changes in the surroundings are called acclimatisation.

6. Why do we need abiotic factors?
Ans: The abiotic factors like air, water, light and heat are very important for the growth of plants. These abiotic factors are also very important for the growth and the development of animals.

7. How are some animals adapted to live in desert?
Ans: Some animals like rats and snakes do not have the long legs like camels to stay away from the effect of heat during the day. They stay in burrows deep in the sand. They come out only during the night.
NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings SAQ Q7

8. Write the features of desert plants.
Ans: 
(i) The leaves in desert plants are either absent or very small.
(ii) Leaves are converted into spines which help to reduce loss of water.
(iii) The stems become thick, flat and green which help in photosynthesis.
(iv) The stem is covered with waxy layer which helps to retain water. In some plants stem is spongy and stores water.
(v) The roots go very deep in the soil to absorb water.
NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings SAQ Q8

9. Explain the adaptation of trees to live in mountain regions.
Ans:
(i) The shape of the trees is of normally cone type.
NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings SAQ Q9
(ii) Branches are sloping.
(iii) The leaves of these trees are needle like.
(iv) These structures prevent accumulation of rainwater and snow over them.

10. Explain the adaptation of animals to live in mountain region.
Ans: 
(i) The animals have thick skin or fur to protect them from the cold.
(ii) Some animals have thick fur on their body, feet and toes which protect them from cold on walking in the snow.
(iii) The goats have strong hooves for running up on rocky slopes.

11. Explain the adaptation of plants to live in water.
Ans: 
(i) Roots are reduced in size which hold the plant.
(ii) Stems are long, hollow and light.
(iii) Stems grow up to the surface of water.
(iv) Leaves and flowers float on the surface of water.
(v) The leaves are covered by the waxy layer which protects the leaves from excessive water.
NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings SAQ Q11

12.What kind of movement do we see in plants?
Ans:
(i) Opening and closing of a flower.
(ii) Growth of a stem and leaves.
(iii) Movement of water, minerals and food from one part of the plant to other.
(iv) Movement of stem towards sunlight and root towards water in the soil.

13. Frogs can live both on land and in water, name the adaptations seen in these animals.
Ans: Frogs have strong back legs that help them in leaping and catching their prey. They have webbed feet which help them to swim in water.

Class 6 Science Chapter 9 LONG ANSWER TYPE QUESTIONS

1.Explain the characteristics oflimng organisms.
Ans. There are following characteristics of living organisms
(i) All living organisms require food. The food gives energy for growth and to maintain other life processes.
(ii) All living organisms show growth. Young ones of animals grow into adults. Plants also grow.
(iii) All living organisms respire. In respiration oxygen is used for the oxidftion of food and carbon dioxide is produced.
(iv) All living organisms respond to stimuli. All plants and animal respond to light, heat and the changes around them.
(v) All living organisms show excretion. The process of getting rid of waste product by the living organisms is called excretion. Plants also remove their wastes.
(vi) All living organisms reproduce. The process by which plants and animals produce their own kind is called reproduction.

2.Write the difference between living and non-living things.
Ans.
NCERT Solutions for Class 6 Science Chapter 9 The Living Organisms and Their Surroundings LAQ Q2

NCERT Solutions

NCERT Solutions for Class 6 Science Chapter 10 Motion and Measurement of Distances

NCERT Solutions for Class 6 Science Chapter 10 Motion and Measurement of Distances

Topics and Sub Topics in Class 6 Science Chapter 10 Motion and Measurement of Distances:

Section Name Topic Name
10 Motion and Measurement of Distances
10.1 Story of transport
10.2 How wide is this desk?
10.3 Some measurements
10.4 Standard Units of Measurements
10.5 Correct Measurement of Length
10.6 Measuring the length of a curved line
10.7 Moving things around us
10.8 Types of motion

1. Give two examples each of modes of transport used on land, water and air.
Ans:
(i) Land—Bus, truck, train.
(ii) Water—Ship, boat.
(iii) Air—Aeroplane, Helicopter.

2. Fill in the blanks:
(i) One metre is___________
(ii) Five kilometre is___________
(iii) Motion of a child on a swing is_____________ .
(iv) Motion of the needle of a sewing machine is_______________ .
(v) Motion of wheel of a bicycle is_____________ .
Ans:
(i) 100
(ii) 5000
(iii) periodic (oscillatory) motion
(iv) periodic oscillatory (v) circular.

3. Why can a pace or a footstep not be used as a standard unit of length?
Ans: Because a pace or a footstep of each and every person is not equal.

4. Arrange the following lengths in their increasing magnitude :
1 metre, 1 centimetre, 1 kilometre, 1 millimetre.
Ans: Ascending order of length:
1 millimetre < 1 centimetre < 1 metre < 1 kilometre

5. The height of a person is 1.65 m. Express it in cm and mm.
Ans:
(a) 1.65 m, as one metre = 100 cm
= 1.65 x 100 cm = 165 cm
(b)65 x 100 x 10 mm = 1650 mm.

6. The distance between Radha’s home and her school is 3250 ,m. Express this distance in km.
Ans:
NCERT Solutions for Class 6 Science Chapter 10 Motion and Measurement of Distances Q6

7. While measuring the length of a knitting needle, the reading of the scale at one  end is 3.0 cm and at the other end is 33.1 cm. What is the length of the needle?
Ans:  Length of the needle = 33.1 cm – 3.0 cm = 30.1 cm.

8. Write the similarities and differences between the motion of a bicycle and a ceiling fan that has been switched on.
Ans: 
(i) Similarity: Both the wheel of a bicycle and a ceiling fan exhibit motion on a fixed axis.
(ii) Dissimilarity: Bicycle moves forward thus executes rectilinear motion but fan does not show such motion.

9. Why could you not use an elastic measuring tape to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with an elastic tape?
Ans:  An elastic measuring tape gives incorrect length of the distance between two points.
Reasons:
(i) The length of the elastic tape varies and depends upon the force by which it is stretched.
(ii) Measurement would vary between 2 or 3 readings even when measured by the same person and by the same elastic tape.
(iii) Measurement would also vary if different persons measure the same distance.

10. Give two examples of periodic motion.
Ans:
(i) Oscillations of a pendulum.
(ii) Motion of swing/motion of earth round the sun.

Class 6 Science Chapter 10 VERY SHORT ANSWER TYPE QUESTIONS

1. Are senses reliable for accurate measurement?
Ans: Our senses are not reliable for accurate measurement.

2. Why can hand span and arm length not be used as standard units of length?
Ans: because these vary from person to person.

3. How many centimetres are there in 1 m?
Ans: 100 cm.

4. Name the measuring device which can be used for measuring the girth of a tree.
Ans: Measuring tape.

5. Give one example of linear motion.
Ans: Motion of stone falling from a certain height.

6. Give an example of circular motion.
Ans: Motion of arms of watch.

7. Name the types of motion in which a body moves along a straight path
Ans: Rectilinear or linear motion.

8.Find the length and breadth of given rectangle in mm and cm.
NCERT Solutions for Class 6 Science Chapter 10 Motion and Measurement of Distances VSAQ Q8
Ans: Using measuring scale (15 cm scale), Length AB = 3 cm and breadth BC = 2 cm.
AB = 3 x 10 = 30 mm
BC = 2 x 10 = 20 mm.

9.Give the unit for measuring the following:
(a) Distance between Delhi and Jaipur.
(b) Thickness of a coin.
(c) Length of your eraser.
(d) Length of your shoe lace.
Ans: 
(a) Kilometre
(b) Millimetre
(c) Centimetre
(d) Centimetre

10. Name the device used to measure the following:
(a) Size of your shoulder.
(b) Size of your wrist.
(c) Your height.
(d) Your weight.
(e) Cloth for curtain.
(f) Circumference of round table.
Ans: 
(a) Measuring tape
(b) Measuring tape
(c) Measuring tape
(d) Weighing balance
(e) Metre scale or measuring tape
(f) A long thread or measuring tape.

Class 6 Science Chapter 10 SHORT ANSWER TYPE QUESTIONS

1. State two precautions to be observed while measuring length with the help of a metre scale.
Ans:  Two precautions are:
(i) The initial point of distance must coincide with the zero reading of metre scale.
(ii) The eye should be kept in line with the point of measurement.

2. Define rest and motion.
Ans:  The objects which do not change their positions with time are said to be at rest. The objects which change their positions with time are said to be in motion.

3. Define the term standard unit.
Ans:  The unit that could be used everywhere as a basic unit of measurement is called a standard unit.

4. How can a measured length be expressed?
Ans: Each measurement has:
(i) A number describing the numerical value.
(ii) The unit in which that quantity is measured.

5. Give one example each of the following types of motion:

(a) Linear
(b) Translation
(c) Circular
(d) Periodic.

Ans:
Types of motion                  Example

(a)  Linear                                  motion of stone falling
(b)  Translatory                         buses
(c) Circular                                 ceiling fan
(d) Periodic                                pendulum of   clock

Class 6 Science Chapter 10 LONG ANSWER TYPE QUESTIONS

1. Why do we need standard unit for measurement?
Ans: We need standard unit for measurement to make our judgement more reliable and accurate. For proper dealing, measurement should be same for everybody. Thus there should be uniformity in measurement. For the sake of uniformity we need a common set of units of measurement, which are called standard units. Nowadays SI units are used in science and technology almost universally.

2. What type of motion do the following objects have?
(a) the galloping of a horse
(b) the needle of a sewing machine
(c) the movements of a mosquito
(d) the blades of an electric fan
(e) the smoke from a lighted dhoopbatti
(f) wheels of moving car.
Ans:
(a) The galloping of a horse: Linear motion.
(b) The needle of a sewing machine: Periodic motion.
(c) Movement of a mosquito: Random motion.
(d) Blade of an electric fan: Circular motion.
(e) The smoke from a lighted dhoopbatti: Random motion.
(f) Wheels of moving car: Linear motion and Rotational motion.

3. Give two examples for each of the following motions:
(i) Linear motion
(ii) Spinning motion
(iii) Oscillatory motion

(iv) Periodic motion 
(v) Vibrational motion

(vi) Circular motion
(vii) Random motion

Ans: 
(i) Linear motion: (a) Rolling of ball on ground, (b) Moving of bicycle on road,
(ii) Spinning motion: (a) Rotating fan, (b) Wheel of sewing machine.
(iii) Oscillatory motion: (a) Pendulum of clock, (b) Motion of a child on a swing,
(iv) Periodic motion: (a) Pendulum of clock, (b) Motion of a swing, heartbeat.
(v) Vibrational motion: (a) String of a guitar, (b) Surface of drums.
(vi) Circular motion: (a) Rotation of fan, (b) Bicycle wheel.
(vii) Random motion: (a) Motion of football players, (b) Movement of mosquito.

NCERT Solutions

NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection

NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection

Topics and Sub Topics in Class 6 Science Chapter 11 Light Shadows and Reflection:

Section Name Topic Name
11 Light, Shadows and Reflections
11.1 Transparent, opaque and translucent objects
11.2 What exactly are shadows?
11.3 A pinhole camera
11.4 Mirrors and reflections

1. Rearrange the boxes given below to make a sentence that helps us understand opaque objects.
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection Q1
Ans:
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection Q1.1

2. Classify the objects or materials given below as opaque, transparent or translucent and luminous or non-luminous:
Air, water, a piece of rock, a sheet of aluminium, a mirror, a wooden board, a sheet of polythene, a CD, smoke, a sheet of plane glass, fog, a piece of red hot iron, an umbrella, a lighted fluorescent tube, a wall, a sheet of carbon paper, the fame of a gas burner, a sheet of cardboard, a lighted torch, a sheet of cellophane, a wire mesh, kerosene stove, sun, firefly, moon.
Ans:
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection Q2

3. Can you think of creating a shape that would give a circular shadow if held in one way and a rectangular shadow if held in another way?
Ans: Yes, there are many things which give a circular shadow if held in one way and a rectangular shadow if held in another way. For example: a cylinder, a circular disc etc.
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection Q3

NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection Q3.1

4. In a completely dark room, if you hold up a mirror in front of you, will you see a reflection of yourself in the mirror?
Ans: No, in a completely dark room no image will be formed because there is no light in the room so no reflection of light takes place and no image will be formed.

Class 6 Science Chapter 11 VERY SHORT ANSWER TYPE QUESTIONS

1. Whether the moon is luminous or non-luminous body?
Ans: Moon is non-luminous body.

2. What is umbra?
Ans: Umbra is the dark region behind object facing light which does not receive light at all.

3. How does a light ray travel?
Ans: Light ray travels in a straight line.

4. Give one natural source of light. 
Ans: Sun is a natural source of light.

5. What is shadow? 
Ans: Shadow is the dark space behind an opaque object where light does not reach.

6. What is penumbra?
Ans: The less darker shadow formed penumbra.on the periphery of dark shadow is called penumbra.

Class 6 Science Chapter 11 SHORT ANSWER TYPE QUESTIONS

1. State difference between a luminous and a non-luminous body.
Ans: The bodies which emit light are called luminous bodies. Example: sun, stars, burning candle etc.
The bodies which does not emit light are called non-luminous bodies. Example: moon, earth, blackboard.

2. Why is the moon not considered as a luminous body?
Ans: Moon is non-luminous body because it shines by reflecting the sunlight falling on it.

3. What is an incandescent body? Give example.
Ans:  The bodies which emit light when heated to a very high temperature are called incandescent bodies. Example: electric bulb.

4. When does a shadow form?
Ans: Shadow is formed when light does not reach behind the opaque object kept in the path of light

5. Draw a diagram to illustrate the formation of umbra and penumbra.
Ans: 
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection SAQ Q5

6. What are the essential conditions for the formation of shadow?
Ans:
(1) There should be an opaque material.
(2) There should be a source of light and screen.
The object must be placed in the path of light. Then shadow is formed on the screen.

7. Define reflection of light.
Ans: When light rays after striking the smooth and shiny surface return to same medium, this phenomenon is called reflection of light.

8. Write difference between shadow and image.
Ans: 
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection SAQ Q8

9. How will you convert a glass sheet into a translucent sheet?
Ans: There are following two methods to convert glass sheet into a translucent sheet:
(i) By smearing a thin layer of oil on glass sheet.
(ii) By covering a side of sheet by butter paper.

10. What is shadow? How does the colour of an opaque object affects the colour of the shadow?
Ans: A dark outline or patch formed by an opaque object that blocks light coming from a source of light is called shadow. The colour of an opaque object does not affect the colour of the shadow.

11. Write the differences between umbra and penumbra.
Ans: 
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection SAQ Q11

12. What do we need in order to see a shadow?
Ans: We need: (i) A source of light (ii) a screen (in) an opaque object.

13. What do you mean by scattering of light?
Ans: When a beam of light falls on a rough surface it is turned back in different directions. It is called scattering of light.

14. A and B are facing the mirror and standing in such a way that A can see B and B can see A. Explain this phenomenon.
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection SAQ Q14
Ans:  The light rays from A falls on the mirror and gets reflected and reaches B, the light from B falls on the mirror and reflects to reach A. The path of light is just reversed as shown.
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection SAQ Q14.1

15. ‘X’ is 20 cm away from the mirror. If he moves few steps closer to the mirror what will happen to the image
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection SAQ Q15
Ans: The size of the image will be same as the size of the object.

16.Write the mirror image of ‘SMART’?
Ans: THAM8

17. Have you ever seen an ambulance? It is written in the form of mirror image on vehicles. Explain why it is done so and give the mirror image of AMBULANCE.
Ans:  The mirror image of AMBULANACE is aovt/yuaMA.
It is written so on the vehicles for the people to see in their rear view mirrors, read it correctly and immediately give way to the vehicle as it carries patients who need urgent medication.

18. You have to cost the shadow of your pencil on the wall with the help of candle in a dark room. How can you obtain the shadow of same size, small size and big size of the same pencil?
Ans: (a)The shadow of the pencil will be small when the pencil is taken close to the wall and away from the candle.
(b)The shadow will be big in size when the pencil is taken closer to the candle.
(c)To get the same sized shadow as the pencil is, adjust the distance between the wall, pencil and candle at equal distances.

Class 6 Science Chapter 11 LONG ANSWER TYPE QUESTIONS

1. What is reflection of light? Explain reflection of light with the help of an activity.
Ans:  When light rays fall on a highly polished (e.g. mirror) smooth surface and return to the same medium, it is called reflection of light.
Activity to show reflection of light: This activity should be done at night or in a dark room. Ask your friend to hold a mirror in his hand at one corner of the room. Stand at another comer with a torch in your hand. Cover the glass of torch with your fingers and switch it on. There should be small gap between your fingers. Direct the beam of torch-light on to the mirror that your friend is holding. Adjust the direction of torch so that patch of light falls on your friend standing in the room. This activity shows the reflection of light also that light travels in straight line.
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection LAQ Q1

2. Explain the manner in which light travels with the help of an activity.
Ans:
 Take a comb and fix it on one side of a thermacol sheet. Fix a mirror on the other side as shown in figure. Spread a dark coloured sheet of paper between the mirror and the comb. Send a beam of light from a torch through the comb. You get a pattern of light similar to that shown in figure. This activity explains the manner in which light travels and gets reflected from a mirror.
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection LAQ Q2

3. Explain that light has the property of rectilinear propagation.
Ans: We take three pieces of cardboard. Place them one on the top of one another and make a hole in the middle of each cardboard by using a thick nail. Erect these cards up on the table at a short distance away from each other. Take a candle which is of the same height as the holes in the cards. Light the candle and place it in front of the cards. We see that the light of candle is visible only when the holes on cards lie in a straight line. If we disturb them the light of candle disappears. This experiment shows that light propagates in a straight line.
NCERT Solutions for Class 6 Science Chapter 11 Light Shadows and Reflection LAQ Q3

NCERT Solutions

NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits

Topics and Sub Topics in Class 6 Science Chapter 12 Electricity and Circuits:

Section Name Topic Name
12 Electricity and Circuits
12.1 Electric cell
12.2 A bulb connected to an electric cell
12.3 An electric circuit
12.4 Electric switch
12.5 Electric conductors and insulators

NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits

1. Fill in the blanks:
(a) A device that is used to break an electric circuit is called_______________
(b) An electric cell has___________
Ans:
(a) switch
(b) two

2. Mark ‘True’ or ‘False’ for the following statements:
(a) Electric current can flow through metals.
(b) Instead of metal wires, a jute string can be used to make a circuit.
(c) Electric current can pass through a sheet of thermocol.
Ans:
(a) True
(b) False
(c) False.

3.Explain why the bulb would not glow in the arrangement shown in fig
NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits Q3
Ans: The bulb would not glow in the arrangement shown in figure because the one end of tester/screw driver is made up of plastic which does not allow the electric current to flow through it.

4. Complete the drawing shown in Fig. 12.9 to indicate where the free ends of the two wires should be joined to make the bulb glow.
NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits Q4
Ans:
NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits Q4.1

5. What is the purpose of using an electric switch? Name some electrical gadgets that have switches built into them.
Ans: Electric switch is used to make electric circuit open or closed for a particular appliance and hence with the help of a switch we can use an appliance according

6. Would the bulb glow after completing the circuit shown in Fig. 12.9 if instead of safety pin we use an eraser?
Ans: No, since eraser is an insulator so it does not allow the current to pass. Hence the bulb will not glow.

7. Would the bulb glow in the circuit shown in Fig. 12.11.
NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits Q7
Ans: Yes, the electric circuit is closed so the bulb will glow.

8. Using the“conduction tester” on an object it was found that the bulb begins to glow. Is that object a conductor or an insulator? Explain.
Ans: Yes, if the object is good conductor of electricity then current will pass through conduction tester and the bulb will glow. Hence the object will be a conductor of electricity.

9. Why should an electrician use rubber gloves while repairing an electric switch at your home? Explain.
Ans: Our body is good conductor of electricity and rubber is insulator. During repairing work if the body comes in contact with current carrying wire then there will not be any accident as rubber does not allow the passage of current through it. Hence electrician uses rubber gloves while repairing an electric switch.

10. The handles of the tools like screwdrivers and pliers used by electricians for repair work usually have plastic or rubber covers on them. Can you explain why?
Ans: Plastic or rubber is an insulator which does not allow electric current to pass through it. The handles of the tools like screwdrivers and pliers used by electricians for repair have covering of plastic or rubber so that electric current may not pass through these tools to the body of the electrician to harm him.

Class 6 Science Chapter 12 VERY SHORT ANSWER TYPE QUESTIONS

1. What is the direction of flow of current in a dry cell?
Ans: . The current flows in closed circuit from +ve to -ve terminal of cell.

2. Name the +ve terminal of dry cell.
Ans:. Carbon rod with a metal cap on it.

3. Name the -ve terminal of a dry cell.
Ans:  Zinc metal plate.

4. What is dry cell?
Ans:  It is a device which converts chemical energy into electrical energy.

5. What is solar cell?
Ans: A device which converts solar energy into electrical energy.

6. What is open circuit?
Ans:  An electric circuit in which electrical contact at any point is broken is called open circuit.

7. Write one use of insulators.
Ans: Insulators are used in making switchboard, handles of testers, screw drivers.

8. What is the name of thin wire in the electric bulb?
Ans: Filament.

Class 6 Science Chapter 12 SHORT ANSWER TYPE QUESTIONS

1. Mention two advantages of a dry cell.
Ans: 
1. It converts chemical energy into electrical energy.
2. It is light and small in size.

2. Draw a diagram showing the two terminals of a bulb.
Ans:
NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits SAQ Q2

3. Draw the circuit diagram for operating a bulb with the help of a dry cell.
Ans:
NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits SAQ Q3

4. Define conductors and insulators. Give one example of each.
Ans:  A conductor is that which easily allows the passage of current through it. Example: Aluminium or any metal.
An insulator is that which does not allow the passage of current through it. Example: Rubber.

5. Identify conductors and insulators from the following:Eraser, paper, matchstick, copper wire, pencil lead, polythene
Ans: Conductors: Copper wire, pencil lead.
Insulator. Eraser, paper, matchstick, polythene.

6. Name the scientist who invented electric cell and the scientist who invented electric bulb.
Ans: Electric cell: Alessandro Volta.
Electric bulb: Thomas Alva Edison.

7. Give one activity to prove that air is an insulator.
Ans: Take an electric circuit, keep the terminals unconnected in the air. The bulb do not glow, as air is an insulator and does not allow the current to flow through it.

8. In any electric circuit, when the switch is on and the current flows through it why do the wire, switches, bulb or devices become hot?
Ans.: This is because electric energy changes into heat energy.

9.The headlights of a car have reflectors behind the bulb. What is the function of reflectors?
Ans: The reflector helps in reflecting the light into a focussed area.

10.If you touch an electric wire carrying current you get a shock, but if on the same wire the birds sit they do not get any shock/current. Explain why?
Ans: When we hold the wire carrying current then the circuit is closed and the current flows from our body and enters earth but the birds sitting on the same wire do not get any current as the circuit is not complete. If the bird touches the earth wire, it will also die due to electric shock.

Class 6 Science Chapter 12 LONG ANSWER TYPE QUESTIONS

1.(1)What is electric circuit?
(2)How many types of electric circuit are there? Define them.
(3)Draw a diagram to show the closed circuit for switch, bulb and dry cell.
Ans: 
(1)The diagram that shows the path of electric current is called electric circuit.
(2)There are two types of electric circuit:
(a) Open electric circuit
(b) Closed electric circuit
(a)Open electric circuit: The circuit in which electrical contact at any point is broken is called open electric circuit.
(b)Closed electric circuit: The circuit in which electric current flows from one terminal of a cell or battery to the other is called a closed circuit.
NCERT Solutions for Class 6 Science Chapter 12 Electricity and Circuits LAQ Q1

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