NCERT Exemplar Class 8 Science Chapter 17 Stars and the Solars System

NCERT Exemplar Class 8 Science Chapter 17 Stars and the Solars System are part of NCERT Exemplar Class 8 Science. Here we have given NCERT Exemplar Class 8 Science Chapter 17 Stars and the Solars System.

NCERT Exemplar Class 8 Science Chapter 17 Stars and the Solars System

Multiple Choice Questions (MCQs)

Question1
Morning star is the name given to
(a) Pole star (b) star Sirius (c) planet Jupiter (d) planet Venus
Answer.
(d) Morning star is the name given to the planet Venus because sometimes it appears in the eastern sky before sunrise.

Question2
Which of the following figures depicts the position of Pole star correctly?

Answer.
(a) Pole star is always situated in the North direction of the earth’s axis.

Question3
The sun appears to move from east to west around the earth. This means that earth rotates from
(a) East to West (b) West to East
(c) North to South (d) West to North
Answer.
(b) The sun appears to move from East to West around the earth, it means that the earth rotates in opposite direction, i.e. from West to East.

Question4
An astronaut standing on the surface of the moon throws a ball upwards. The ball would
(a) directly fall down from the point it is released
(b) hang in space
(c) go up and then, come back to the surface of the moon
(d) keep going up never to come back
Answer.
(c) The ball will go up and then comes down because at moon, acceleration due to gravity is less than that of the earth.

Question5
Suppose a new planet is discovered between Uranus and Neptune. Its time period would be
(a) less than that of Neptune
(b) more than that pf Neptune
(c) equal to that of Neptune or Uranus
(d) less than that of Uranus
Answer.
(a) As we know that, the,time period is directly proportional to the distance from the sun, so the new planet discovered between Uranus and Neptune will have less time period than the neptune and greater than the Uranus.

Question6
The change in seasons on the earth occurs because
(a) the distance between the earth and the sun is not constant
(b) the axis of rotation of the earth is parallel to the plane of its orbit
(c) the axis of rotation of the earth is perpendicular to the plane of its orbit
(d) the axis of rotation of the earth is tilted with respect to the plane of its orbit
Answer.
(d) The axis of rotation of the earth is not perpendicular to the plane of its orbit. The tilt is responsible for the chang of seasons on earth.

Question7
The first of a month is the new moon day. On fifteenth day of the same month, which of the following figures would represent the phase of the moon?

Answer.
(a) After 15 days of new moon day, there will be a full moon day and therefore, we are able to see the full moon on the fifteenth day of the same month.

Very Short Answer Type Questions

Question8
Do stars emit light only during night?
Answer.
No, stars emit light all the time. But, we are not able to see their light due to excess brightness of the Sun.

Question9
Paheli and Boojho observe a bright object in the night sky which was not twinkling. Paheli says, it is a star and Boojho says it is a planet. Who is correct?
Answer.
Boojho is correct. Only planet has the property not to twinkle, however, light due to star comes from very far distance and therefore, twinkles.

Question10
State whether the following are True/False.
(i) The planet nearest to us is Jupiter.
(ii)All the stars are at the same distance from us.
(iii)The planets do not emit light of their own.
(iv)The planets keep changing their position with respect to stars.
(v) The planet Venus appears in the eastern sky before sunrise.
(vi)The plane in which the earth revolves around the Sun is called equatorial plane of earth.
Answer.
(i) False, nearest planets to the Earth are Mars and Venus.
(ii)False, stars are at different distances from us.
(iii)True, only stars emit light of their own.
(iv)True, because the planets are always in motion.
(v) True, planet Venus is also called morning star.
(vi)False, the Earth revolves around the Sun in orbital plane.

Question11
John saw full moon on a particular day. After how many days, he will be able to see the full moon again?
Answer.
He will’be able to see full moon gpproximately after 29 days because first, the moon size will decrease to zero, i.e. new mdcn day and then will increase from the 16th day, i.e. crescent moon will appear and finally on next 15th day, there will be a full moon again.

Question12
In the picture of rotating earth given as figure mark the position of Pole star.

Answer.
Pole star is situated in the direction of earth’s axis as shown below. If does not appear to move.

Question13
In the given figure, out of the positions A, B, C and D which will indicate
the position of the sun? Draw the sun at the appropriate position.

Answer.

Question 14
In figure mark the arrows (<-),(->),(↓), or (↑) to show the direction of Sunlight.

Answer.

Short Answer Type Questions

Question 15
A star is 10 light years away from the earth. Suppose it brightens up suddenly today. After how much time shall we see this change?
Answer.
As 1 light year is the distance covered by light in one year. So, if the star which is 10 light years away from the earth glows today, then it will be seen after 10 years.

Question 16
Meteors are not visible during the day time. Explain the reason.
Answer.
Meteors are very small objects which glow due to friction when they enter the earth’s atmosphere.
They are not visible during the daytime because their brightness is extremely small as compared to that of the sun.

Question 17
Why does the moon change its shape daily?
Answer.
Moon changes its shape daily because it revolves around the earth and we see only that part of the moon from which light of the sun is reflected towards us.

Question 18
Paheli saw the moon through a glass window at 8:00 pm. She marked the position of the moon on the glass pane. She got up at 4 am in the morning. Will the moon be visible at the same position?
Answer.
No, Paheli will not be able to see the position of the moon at the same place because due to revolution of the moon around the earth, the position of the moon keeps on changing during the night.

Long Answer Type Questions

Question 19
Suppose the moon emits light of its own. Would it still have phases? Justify your answer.
Answer.
No, it will not have the phases because the phases are due to the reflection of different intensities of light falling on moon from the sun due to its revolution around the Earth. Now, since the moon will have its own light, it need not to be dependent on Sun’s light to glow, so it will glow continuously and completely.

Question 20
Figure shows comets without their tail. Show the tails of the comets at positions A, B, and C. In which position will the tail be longest?

Answer.
The tail of the comet is always directed away from the Sun.

The tail will be longest in the position B because the tail is visible only when the comet passes through the inner solar system and B is the nearest point.

Question 21
Explain why we always see the same side of the moon.
Answer.
We always see the same side of the moon because the period of rotation of the moon on its axis is equal to the period of its revolution around the earth, so we only see the side that faces us and this side faces at us all the time,

Question 22
Look at the figure carefully and answer the following questions:

(a) In which part of the sky would you see the full moon in the evening?
(b) In which part of tfie sky would you see the crescent moon in the evening?
Answer.
(a) We will see the full moon on the left side (according to figure) in the evening.
(b) On the right side (lower part), we will see the crescent moon which is on the next day of the new moon day.

Question 23
Write the names of all planets in the figure.

Answer.
According to orbits (starting from the first), the names of planets are :
(i) Mercury  (ii)Venus
(iii)Earth     (iv) Mars
(v) Jupiter   (vi) Saturn
(vii)Uranus (viii) Neptune

Question 24
Suppose the distance between the earth and sun becomes half of its present distance. What is likely to happen to life?
Answer.

So, the days in a year will be approx. 129 instead of 365 days.
Life may no longer exist.

Question 25
Explain with a diagram how you can locate pole star with the help of the constellation Great Bear (Ursa Major).
Answer.
We can locate the pole star with the help of Ursa Major in the following way:
(i) Draw an imaginary line from the two end stars of Ursa Major.
(ii)Extend this imaginary line towards the North direction.
(iii)This line will lead to a star which is not too bright.
(iv)This is a Pole star.

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We hope the NCERT Exemplar Class 8 Science Chapter 17 Stars and the Solars System help you. If you have any query regarding NCERT Exemplar Class 8 Science Chapter 17 Stars and the Solars System, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current

NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current are part of NCERT Exemplar Class 8 Science. Here we have given NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current.

NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current

Multiple Choice Questions (MCQs)

Question 1
An electric current can produce
(a) heating effect (b) chemical effect
(c) magnetic effect (d) chemical, heating and magnetic effects
Answer.
(d) When an electric current is passed through a conducting solution, it causes chemical reactions. The resulting effect is called chemical effect of current.
When an electric current is passed through a bulb, its filament gets heated to a high temperature and bulb starts glowing. The resulting effect is heating effect of current. Whenever an electric current te passed through a circuit, a magnetic field is produced around it. The resulting effect is magnetic effect of current. Thus, an electric current can produce chemical, heating and magnetic effects. •

Question 2
Boojho and Paheli performed experiments taking similar bulbs and cells but two different solutions A and B as shown in the figure.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 1
They found that the bulb in the set up A glows more brightly as compared to that of the set up B. You would conclude that
(a) higher current is flowing through the circuit in set up A
(b) higher current is flowing through the circuit in set up B
(c) equal current is flowing through both the circuits
(d) the current flowing through the circuits in the two set up cannot be compared in this manner
Answer.
(a) Bulb in the set up A glows more brightly because higher current is flowing through the circuit in set up A, as solution AIs better conductor of electricity than that of B.

Question 3
Boojho’s unde has set up an electroplating factory near his village. He should dispose off, the waste of the factory
(a) in the nearby river
(b) in the nearby pond
(c) in the nearby corn field
(d) according to the disposal guidelines of the local authority
Answer.
(d) In electroplating factory, the disposal of the used conducting solution is a major concern because it is a polluting waste, therefore it should be disposed off according to the disposal guidelines of the local authority.

Question 4
When electric current is passed through a conducting solution, there is a change of colour of the solution. This indicates
(a) the chemical effect of current (b) the heating effect of current
(c) the magnetic effect of current (d) the lightning effect of current
Answer.
(a) The passage of an electric current through a conducting solution causes chemical reactions. As a result, change of colour of solution occurs. This indicates the chemical effect of current.

Question 5
Which one of the following solutions will not conduct electricity?
(a) Lemon juice (b) Vinegar
(c) Tap water (d) Vegetable oil
Answer.
(d) Vegetable oil will not conduct electricity because it does not make ions easily.

Question 6
Which of the following metals is used in electroplating to make objects appear shining?
(a) Iron (b) Copper
(c) Chromium (d) Aluminium
Answer.
(c) Chromium is used for electroplating to make objects appear shining because chromium has a shiny appearance and it resists scratches.
Question 7
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 2
Which of the following solutions will not make the bulb glow in figure?
(a) Sodium chloride (b) Copper sulphate
(c) Silver nitrate (d) Sugar solution in diluted water
Answer.
(d) Sugar solution in diluted water does not make ions and is a poor conductor of electricity. Therefore, it will not make the current to flow through it and the bulb will not glow.

Very Short Answer Type Questions

Question 8
Fill in the blanks.
(i) The object to be electroplated is taken as……….electrode.
(ii)One of the most common applications of chemical effect of electric
current is……….
(iii)Small amount of a mineral salt present naturally in water makes it a………. of electricity.
(iv)Electroplating of………. is done on objects like water taps and
cycle bell to give them a shiny appearance.
Answer.
(i) Negative The object to be electroplated is taken as negative electrode or cathode, so that the free ions get deposited on it.
(ii) Electroplating It is thaprocess of depositing a layer of any desired metal on another material by means of electricity.
(iii) Good conductor Small amount of a mineral salt present naturally in water makes it a salt solution, therefore it becomes good conductor of electricity.
(iv) Chromlum Because chromium has a shiny appearance, it resists scratches and does not corrode.

Question 9
Why is a layer of zinc coated over iron?
Answer.
Layer of zinc is coated over iron because zinc prevents it from rust and corrosion.

Question 10
Will the solution of sugar in distilled water conduct electricity?
Answer.
No, the solution of sugar in distilled water is a poor conductor of electricity and therefore current cannot pass through it.

Question 11
Name the effect of current responsible for the glow of the bulb in an electric circuit.
Answer.
Heating effect of electric current is responsible for the bulb to glow in an electric circuit. Due to heating effect, the filament of the bulb gets heated to a high temperature and it starts glowing.

Short Answer Type Questions

Question12
Boojho made the circuit given in the figure and observed that the bulb did not glow. On Paheli’s suggestion, he added one more cell in the circuit. The bulb now glows. Explain.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 3
Answer.
Initially, the bulb was not glowing because the voltage required to make the bulb glow was not sufficient. With the addition of another cell, the voltage increases, i.e. the current through the bulb increases more than a particular value and the bulb starts glowing because it gets sufficient energy to heat its filament.

Question 13
Paheli set up an experiment using liquid A in the beaker as shown in the figure. She observed that the bulb glows. Then, she replaced the liquid A by another liquid B. This time the bulb did not glow. Boojho suggested replacing the bulb by an LED. They observed that the LED glows. Explain.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 4
Answer.
Liquid A is a good conductor of electricity and it allows the maximum current to pass through it which is sufficient to glow the bulb.
But when it is replaced by another liquid B, bulb does not glow because the current through liquid B could be weak and therefore unable to make the bulb glow.
But the small current which is passing through B is sufficient to glow a low voltage LED, so it glows.

Question 14
Paheli wants to deposit silver on an iron spoon. She took silver nitrate (AgNO3) solution in a beaker and set up a simple circuit for electroplating. Which terminal of the battery should the spoon be connected to? What mjjterial should the other electrode be made of?
Answer.
Spoon should be connected to the negative terminal of the battery. The other electrode should be made of silver, so that silver ions get deposited on an iron spoon.

Question 15
Why is tin electroplated on iron to make cans used for storing food?
Answer.
Electroplating of tin is done on the iron to make cans used for storing food because tin is less reactive than iron. Coating of tin prevents food from coming in contact with iron and thus, prevents it from getting spoiled.

Question 16
Observe figure.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 5
Which of these two circuits A or B shows the correct observation?
Answer.
It is not clear from the diagram that what is A and B. So, we cannot predict the actual solution. But if we compare with NCERT activity, this seems to be a potato and the correct diagram is A because positive terminal makes the greenish blue spot on the potato, due to the chemical effect of current in potato.

Question 17
Observe the following circuits carefully. In which circuit will the bulb glow? Write Yes or No in the blank space provided along each of the circuit given in the figure.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 6
Answer.
(a) No, because piece of coal is a poor conductor of electricity.
(b) Yes, because iron nail is a good conductor of electricity.
(c) No, because eraser is a poor conductor of electricity.
(d) Yes, because steel spoon is a good conductor of electricity.

Long Answer Type Questions

Question18
An electric current is passed through a conducting solution. List any three possible observations.
Answer.
Three’ possible observations are *
(i) The colour of the solution may change depending upon the electrodes.
(ii)The temperature of the solution may increase.
(iii)Bubbles near the electrodes can be seen.’

Question19
In the circuit given in the figure,
Boojho observed that copper is deposited on the electrode connected to the negative terminal of the battery.
Paheli tried to repeat the same experiment. But she could find only one copper plate. Therefore, she took a carbon rod as negative electrode. Will copper be still deposited on the carbon rod? Explain your answer.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 7
Answer.
Yes, Gopper from the copper sulphate solution will be deposited on the carbon rod. When electric current is passed through the copper sulphate solution, copper sulphate dissociates into copper and sulphate.
The free copper gets drawn to the electrode connected to the negative terminal of the battery, i.e. carbon rod and gets deposited on it. Thus, Paheli will obtain a coating of copper on carbon rod.

Question 20
Observe the circuit cjiven in the figure.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current img-8
Boojho set up this circuit for purification of copper. What will be the nature of – (a) plate A (b) plate B (c) and the solution.
Explain the process of purification
Answer.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 9
We take CuSO4as solution “and dip a pure copper plate as cathode (-ve) and impure copper plate as anode (+ve) in it. The copper from impure copper plate is transferred to the pure copper plate by the process of electroplating and impurities deposit at the bottom. In this way, the copper plate beoomes purified.

Question 21
Observe the following circuit given in the figure.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 10
Current does not flow in the circuit, if there is a gap between the two wires. Does it indicate that air is a poor conductor of electricity? Does air never conduct electricity? Explain.
Answer.
Yes, if current is not flowing through the air gap between the wires, it means that air is a poor conductor of electricity. No, air conducts electricity only when there is great voltage or there is some moisture in air, such as during lightning.

Question 22
Boojho made the circuit as shown in the figure. He wanted to observe what happens when an electric current is passed through water. But he forgot to add a few drops of lemon juice to water. Will it make any difference to his observations? Explain
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 11
Answer.
No current will pass through the circuit, if the water is distilled water and lemon juice is not added. If the water is saity, a small current will pass through the circuit. Adding few drops of lemon juice in water will increase the conductivity of the solution and large amount of current will flow easily.

Question 23
Observing that the bulb does not glow in the circuit shown in Fig. (A) Boojho changed the circuit as shown in Fig. (B). He observed deflection in the magnetic compass.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 12
(a) What does the deflection in magnetic compass indicate?
(b) Why did the bulb not glow in Fig. (A)?
(c) What would be the effect of increase in the number of turns in the coil wound around the magnetic compass in Fig. (B)?
(d) What will be observed if the number of cells are increased in the circuit shown in Fig. (B)?
Answer.
(a) The deflection in the magnetic compass shows that the current is flowing in the circuit.
(b) The bulb did not glow, because the current passing through the circuit could be weak to make it glow. Also, it may happen because of other reasons like bulb may be fused or the connections may be loose.
(c) Increase in the number of turns in the coil wound around the magnetic compass •would increase the magnetic field around the magnetic compass which will result in the increase in the deflection in magnetic compass.
(d) Increase ‘in the number of cells will further increase the deflection in magnetic compass.

Question 24
You are provided with a magnetic compass, an empty matchbox, a battery of two cells and connecting wires. Using these objects, how will you make a tester for testing an electric circuit? Draw the necessary circuit diagram and explain.
Answer.
Take the tray from the inside of a discarded matchbox. Wrap an electric wire a few times around the tray. Place a’small compass needle inside it. Now, connect one free end of the wire to the one terminal of a battery. Leave the other end free.
Take another piece of wire and connect it to the other terminal of the battery. Join the free ends of two wires momentarily.
The compass needle shows deflection due to the magnetic effect of current. Your tester with two free ends of the wire is ready.
NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current 13

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We hope the NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current help you. If you have any query regarding NCERT Exemplar Class 8 Science Chapter 14 Chemical Effects of Electric Current, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals

NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals are part of NCERT Exemplar Class 8 Science. Here we have given NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals.

NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals

Multiple Choice Questions

Question. 1 Sets of reproductive terms are given below. Choose the set that has an incorrect combination.
(a) Sperm, testis, sperm duct, penis
(b) Menstruation, egg, oviduct, uterus
(c) Sperm, oviduct, egg, uterus
(d) Ovulation, egg, oviduct, uterus
Answer. (c) Set (c) has an incorrect combination. This is because it has parts of both male and female reproductive system.
Sperm is the male gamete while oviduct, egg and uterus are parts of female reproductive system.

Question. 2 In humans, the development of fertilised egg takes place in the
(a) ovary (b) testis (c) oviduct (d) uterus
Answer. (d) The development of fertilised egg takes place in the uterus (womb). The embryo gets embedded in the wall of the uterus for development by implantation.

Question. 3 In the list of animals given below, hen is the odd one out.Human being, cow, dog, hen.
The reason for this is
(a) it undergoes internal fertilisation (b) it is oviparous
(c) it is viviparous (d) it undergoes external fertilisation
Answer. (b) Hen is odd one out because it is oviparous, i.e. it lays egg from which young ones are hatched later on.
The rest three (human being, cow and dog) are viviparous, i.e. give birth to young ones after they are fully developed.

Question. 4 Animals exhibiting external fertilisation produce a large number of gametes. Pick the appropriate reason from the following.
(a) The animals are small in size and want to produce more offsprings
(b) Food is available in plenty in water
(c) To ensure better chance of fertilisation
(d) Water promotes production of large number of gametes
Answer. (c) A large number of gametes are released by such animals to ensure better chance of fertilisation. Since, the gametes are laid in water, many of them are carried away by moving water, wind or rain and many are eaten by other animals.Therefore, production of large number of gametes is necessary.

Question. 5 Reproduction by budding takes place in
(a) Hydra (b) Paramecium (c) Amoeba (d) Bacteria
Answer. (aj In Hydra, reproduction takes place by budding. A small part of the body of an organism grows as ‘bud’ which then detaches and becomes a new organism.
The other options Amoeba, Paramecium and bacteria reproduce asexually by binary fission.

Question. 6 Which of the following statements about reproduction in humans is correct?
(a) Fertilisation takes place externally
(b) Fertilisation takes place in the testes
(c) During fertilisation, egg moves towards the sperm
(d) Fertilisation takes place in the human female
Answer. (d) Fertilisation in humans takes place in the female body. The sperms of man are introduced by penis into female’s body through vagina.
The sperms then pass through the uterus and reach to oviducts. It is here, that sperm combines with egg to form zygote (i.e fertilisation occurs).

Question. 7 In human beings, after fertilisation, the structure which gets embedded in the wall of uterus is
(a) ovum (b) embryo (c) foetus (d) zygote
Answer. (b) After fertilisation, the zygote divides repeatedly to form a ball of hundreds of cells called an embryo. The embryo moves down from oviduct into the uterus, where it gets embedded. This is called implantation.

Question. 8 Aquatic animals in which fertilisation occurs in water are said to be
(a) viviparous without fertilisation (b) oviparous with external fertilisation
(c) viviparous with internal fertilisation
(d) oviparous with internal fertilisation
Answer. (b) The aquatic animals in which fertilisation occurs in water are oviparous with external fertilisation. They lay eggs and release sperms outside body in the water for fertilisation to take place. The young one top is formed outside the body in water from the zygote formed inside eggs.

Question. 9 After fertilisation, the resulting cell which gives rise to a new individual is the
(a) embryo (b) ovum (c) foetus (d) zygote
Answer. (d) After fertilisation (i.e. combining of sperm with the egg), zygote is formed. It is the beginning of formation of a new individual. All the multicellular animals start their life from a single cell called zygote.

Question. 10 In human beings, the correct sequence of events during reproduction is
(a) gamete formation, fertilisation, zygote, embryo
(b) embryo, zygote, fertilisation, gamete formation
(c) fertilisation, gamete formation, embryo, zygote
(d) gamete formation, fertilisation, embryo, zygote
Answer. (a) In human beings, sexual reproduction takes place by the combination of gametes, i.e. sperm and egg, formed in male and female, respectively. The fusion of gametes is called fertilisation.
The fusion forms a zygote, which divides repeatedly to form the embryo. The embryo gets implanted in female uterus for further development to form foetus.

Very Short Answer Type Questions

Question. 11 Although two cells called gametes fuse, the product formed is a single cell called zygote. Justify.
Answer. During fertilisation, only the nuclei of male and female gametes fuse. The sperm reaches to egg and only its nucleus enters the egg cell and fuses with the egg nucleus to form the single-celled structure called zygote. The cell formed consists of only one nucleus but is diploid in nature.

Question. 12 Stages in the life cycle of silkworm are given below. Write them in sequential order.
Pupa, Egg, Silk moth, Caterpillar
Answer. The stages in the life cycle of silkworm occurs in following sequence:
NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals 1
This process of transformation from an immature form of an animal to its adult form in two or more distinct stages is called metamorphosis.

Question. 13 What is the importance of reproduction?
Answer. Reproduction is important for organisms because it ensures the continuity of life on earth. It is the means of multiplication and perpetuation of a species. It also creates variations among the population.

Question. 14 In markets, eggs of birds are available but never eggs of dogs, why?
Answer. Birds are oviparous, i.e. lay eggs outside their body. So, it is easy to collect their eggs and these are thus available in market.
On the contrary, dogs are viviparous, i.e. do not lay eggs but give birth to young ones. Their eggs are extremely small which remain inside their bodies.

Question. 15 The eggs of frogs do not have shells for protection, yet they are safe in water, how?
Answer. Frog’s eggs are without any external covering or shell but a layer of jelly hold the eggs together, thus providing them protection.
This jelly or gelatinous covering also protects them from drying up and prevents them from being eaten up by other animals or predators.

Short Answer Type Questions

Question. 16 Fill up the blanks with the terms given below:
body, asexual, binary, single, nucleus
Amoeba is a………….. celled organism. It reproduces by…………… reproduction.
The process of reproduction begins by the division of its………….. into two.
This is followed by the division of its …………… into two. This type of reproduction is called…………… fission.
Answer. Single,asexual, nucleus, body, binary

Question. 17 The term ‘metamorphosis’ is not used while describing human development. Why?
Answer. The term ‘metamorphosis’ is not used while describing human development because in human beings, body parts of an adult are present from the time of birth itself, i.e. while beginning of life as a baby and until you are an adult, the basic plan of body does not change.
On the contrary, in metamorphosis, the parts of the adult are different from those at the time of birth.

Question. 18 Mother gives birth to a baby but the baby has characters of both parents. How is this possible?
Answer. Although, mother gives birth to a baby but the baby is formed from the fertilisation of male and female gamete that comes from the father and mother, respectively. The nuclei of both the parent gametes fuse to form a zygote with new character combinations from both parents.
Hence, the zygote formed from fertilisation have characters of both the parents. This zygote develops inside the female body (uterus) and finally takes birth as baby.

Question. 19 How is reproduction in Hydra different from that in Amoeba?
Answer. Both Hydra and Amoeba reproduce asexually involving only single parent but the mode of reproduction is different.
Hydra reproduces from bulges or buds arising from the parent body that grows’ and matures into another organism, i.e. by budding, while Amoeba reproduces by binary fission, i.e. splitting of parent organism to form two new organisms.

Question. 20 State whether the following statements are True/False
1. External fertilisation can occur both in water and on land.
2. The eggs of fish are covered by hard shells for protection.
3. Human egg has a head, middle piece and tail.
4. In adult human females, a single mature egg is released into an oviduct every month.
Answer.1. False, external fertilisation occurs only in water and not on land.
2. False, the eggs of fish are covered by gelatinous or jelly-like covering for protection.
3. False, human sperm has a head, middle piece and tail.
4. True

Question. 21 Why do only malejjametes have a tail?
Answer. Male gametes or sperms have tail to facilitate movement of sperms and help them to reach the egg (female gamete) for fertilisation.

Question. 22 What does figure represent?
NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals 2
Answer. The .figure represents binary fission with a dividing nucleus parent in Amoeba. The single-celled parent Amoeba divides to form two daughter cells that develop into two independent Amoebae.

Question. 23 Observe the given figure and answer the questions that follow.
NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals 3
(a) Label A and B.
(b) Identify the process.
(c) What happens during the process and what is formed?
Answer. (a) A-sperm, B-ovum (egg).
(b) The process is fertilisation.
(c) During the process, the sperm nucleus fuses with the egg nucleus as a result of which a zygote is formed.

Long Answer Type Questions

Question. 24 How can we say that fish exhibits external fertilisation?
Answer. Female fish lay eggs in water while male fish releases its sperms in water. Sperms swim and reach the eggs of fish, randomly due to water currents.When a sperm comes in contact with the viable egg, nuclei of both the cell fuses to form a zygote. This process of fertilisation takes place in water outside the female body, hence fertilisation is external in fishes.

Question. 25
NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals 4
After Observing above figure, answer the following,
(a) Read the following statements and label them in the figure.
1.The part which produces female gametes.
2. The part where development of the baby takes place.
3. The part through which the developing embryo passes to reach the uterus.
(b)Explain the future development of the embryo that would take place
after it gets embedded in the uterus.
Answer. (a) The parts in the figure are labelled below:
NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals 5
(b) The embryo continues to grow and develop after it gets embedded in the uterus. It divides and differentiates into three germ layers which give rise to different body : parts such as hands, legs, head, eyes, ears, etc. This stage where all the body parts are distinct and easily identified in developing embryo is called foetus.
A human embryo becomes a foetus after about 8 weeks of pregnancy. After completion of development of foetus (i.e. after about 38 weeks or 9 months), mother gives birth to baby.

Question. 26 Hens and frogs are both oviparous exhibiting different types of fertilisation, explain.
Answer. Hens are oviparous in which internal fertilisation takes place. The fertilised egg divides repeatedly to form an embryo inside the body. The embryo however, travels down the oviduct with many protective layers forming around it. After the hard egg shell is formed around the developing embryo, the hen lays the eggs outside. After about 3 weeks, the development of chick from egg takes place.
On the contrary, frogs are oviparous in which external fertilisation occurs. The frogs lay eggs and sperms in water, which comes in contact to undergo fertilisation. In this way, a female frog’s eggs get fertilised by sperms outside its body, i.e external fertilisation.
The fertilised eggs are covered by a jelly for protection. The development of embryo takes place in the egg in water, i.e they are oviparous.

Question. 27 Observe the following figures.
NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals 6
(i) Identify the stages (a) to (d) in figure during development of human baby.
(ii) Arrange the stages in correct sequence of development.
(iii) Explain the development that takes place in any one stage.
Answer. 1. The figures showing stages during development of embryo are identified as
(a) Embedding of the embryo in the uterus (implantation).
(b) Fertilisation (fusion of egg and sperm).
(c) Stages in development of an embryo from the zygote in the oviduct, till it gets embedded in uterus.
(d) Zygote (showing fusion of nuclei)
2. The above stages in sequence are:
NCERT Exemplar Class 8 Science Chapter 9 Reproduction in Animals img-7
3. Development of embryo The embryo after being implanted in uterus, continues to develop and divide and differentiate into body parts. The stage of embryo when body parts become distinct and identified is called foetus. After complete development of foetus, mother gives birth to baby.

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NCERT Exemplar Class 6 Science Chapter 15 Air Around Us

NCERT Exemplar Class 6 Science Chapter 15 Air Around Us are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 15 Air Around Us.

NCERT Exemplar Class 6 Science Solutions Chapter 15 Air Around Us

Multiple Choice Questions

Question 1.
Which of the following statements is incorrect?
(a) All living things require air to breathe.
(b) We can feel air but we cannot see it.
(c) Moving air makes it possible to fly a kite.
(d) Air is present everywhere but not in soil.
Solution:
(d): Air is omnipresent and is present in the soil also. This can be proved by a simple activity where a lump of dry soil is taken in a beaker or a glass. When water is added to the soil, it displaces the air which is seen in the form of bubbles.

Question 2.
Wind does not help in the movement of which of the following?
(a) Firki
(b) Weathercock
(c) Ceiling fan
(d) Sailing yacht
Solution:
(c): Ceiling fan moves by electricity, and hence, wind does not help in the movement of ceiling fan.

Question 3.
What is not true about air?
(a) It makes the windmill rotate.
(b) It helps in the movements of aeroplanes.
(c) Birds can fly due to presence of air.
(d) It has no role in water cycle.
Solution:
(d) : Air plays a major role in water cycle. Air helps the water vapour to rise up to form clouds. Evaporation of water, cloud formation and falling of rain, all take place in the atmosphere.

Question 4.
Mountaineers carry oxygen cylinders with them because
(a) there is no oxygen on high mountains
(b) there is deficiency of oxygen on mountains at high altitude
(c) oxygen is used for cooking
(d) oxygen keeps them warm at low temperature.
Solution:
(b): With increase in altitude, the atmosphere gets thinner and the supply of oxygen is reduced. This causes difficulty in breathing on hill stations and mountains. Therefore, while climbing high mountains, mountaineers carry oxygen cylinders with them.

Question 5.
Boojho took an empty plastic bottle, turned it upside down and dipped its open mouth into a bucket filled with water. He then tilted the bottle slightly and made the following observations.
(i) Bubbles of air came out from the bottle.
(ii) Some water entered the bottle.
(iii) Nitrogen gas came out in the form of bubbles and oxygen got dissolved in water.
(iv) No bubbles formed, only water entered the bottle.
Which observations is / are correct?
(a) (i) and (ii)
(b) (iv) only
(c) (iii) and (iv)
(d) (i) only
Solution:
(a)

Question 6.
Which of the following components of air is present in the largest amount in the atmosphere?
(a) Nitrogen
(b) Oxygen
(c) Water vapour
(d) Carbon dioxide
Solution:
(a) Atmosphere cpntains 78% nitrogen, 21% oxygen and remaining 1% is formed by carbon dioxide, water vapour, few other gases and dust particles. Thus, atmosphere contains nitrogen in the largest amount.

Question 7.
The components of air which are harmful to living beings are
(a) nitrogen and carbon dioxide
(b) dust and water vapour
(c) dust and smoke
(d) smoke and water vapour.
Solution:
(c) Water vapour, nitrogen and carbon dioxide are useful to living beings. Water vapour is important for the water cycle in nature. Nitrogenisnecessaryforplants. Carbon dioxide is essential for photosynthesis.

Question 8.
Ushatooka lump of dry soil in a glass and added water to it till it was completely immersed. She observed bubbles coming out. The bubbles contain
(a) water vapour
(b) only oxygen gas
(c) air
(d) none of these.
Solution:
(c) When the water is poured on the lump of soil, it displaces the air trapped in it which is seen in the form of bubbles.

Very Short Answer Type Questions

Question 9.
State whether the following statements are true or false. If false, correct them.
(a) Plants consume oxygen for respiration.
(b) Plants produce oxygen during the process of making their own food.
(c) Air helps in the movements of sailing yachts and gliders but plays no role in the flight of birds and aeroplanes.
(d) Air does not occupy any space.
Solution:
(a) True
(b) True
(c) False – Air helps in the movement of sailing yachts and gliders and also helps in the flight of birds and aeroplanes.
(d) False – Air does occupies space.

Question 10.
In a number of musical instruments, air plays an important role. Can you name such instruments?
Solution:
Air plays an important role in a number of musical instruments such as flute, trumpet, mouth organ, shehnai and harmonium.

Question 11.
In the boxes of column I the letters of some words got jumbled. Arrange them in proper form in the boxes given in column II.
NCERT Exemplar Class 6 Science Chapter 15 Air Around Us Q11
Solution:
NCERT Exemplar Class 6 Science Chapter 15 Air Around Us Q11.1

Question 12.
Make sentences using the given set of words.
(a) 99%, oxygen, nitrogen, air, together
(b) Respiration, dissolved, animals, air aquatic
(c) Air, wind, motion, called
Solution:
(a) Oxygen and nitrogen together make up 99% of the air.
(b) Aquatic animals use dissolved air for respiration.
(c) Air in motion is called wind.

Short Answer Type Questions

Question 13.
A list of words is given in a box. Use appropriate words to fill up the blanks in the following statements.
[Air, oxygen, wind, water vapour, mixture, combination, direction, road, bottles, cylinders]
(a) The ______ makes the windmill rotate.
(b) Air is a ______ of some gases.
(c) A weather cock shows the in which the air is moving at that place.
(d) Mountaineers carry oxygen ___ with them, while climbing high mountains.
Solution:
(a) wind
(b) mixture
(c) direction
(d) cylinders

Question 14.
Observe the picture given in Fig. 15.1 carefully and answer the following questions.
NCERT Exemplar Class 6 Science Chapter 15 Air Around Us img-1
(a) What is covering the nose and mouth of the policeman?
(b) Why is he putting a cover on his nose?
(c) Can you comment on air quality of the place shown in the Fig.15.1?
Solution:
(a) The policeman is wearing a mask to cover his nose and mouth.
(b) He puts a cover on his nose to protect himself from dirt and polluted air. A mask avoids exposure to the harmful exhaust of vehicles, thus prevents the harmful gases and dust particles entering our body.
(c) The given figure shows a polluted area where the air quality is not good. It is due to the smoke and harmful gases such as carbon monoxide and sulphur dioxide emitted by the automobiles along with dust particles present in the air.

Question 15.
Garima observed that when she left her tightly capped bottle full of water in open sunlight, tiny bubbles were formed all around inside the bottle. Help Garima to know why it happened?
Solution:
Air dissolved in water starts escaping in the form of tiny bubbles due to heat from the sun. Thus, tiny bubbles were formed all around inside the bottle.

Question 16.
Match the items of column I with the items of column II.

Column-1 Column-ll
(a) Weather cock (i) Gases and fine dust particles
(b) Mountaineers (ii) Sailing yacht
(c) Fine hair inside the nose (iii) Oxygen cylinders
(d) Smoke (iv) Direction of air flow
(e) Wind (v) Prevent dust particles

Solution:
(a) – (iv)
(b) – (iii)
(c) – (v)
(d) – (i)
(e) – (ii)

Long Answer Type Questions

Question 17.
Explain the following observations very briefly.
(a) A firki does not rotate in a closed area.
(b) The arrow of weather cock points towards a particular direction at a particular moment.
(c) An empty glass in fact is not empty.
(d) Breathing through mouth may harm you.
Solution:
(a) A firki or pmwheel rotates when placed in an open area due to the moving air present all around. In a closed area, there is a lack of air movement which does not support the rotation of a firki.
(b) A weather cock is an instrument used for indicating the direction of the wind. It consists of an arrow, mounted at its centre of gravity so it can move freely about a vertical axis. Therefore, the arrow points towards a particular direction at a particular moment to show the latest direction of the wind movement.
(c) An empty glass is filled with the air. ft is filled completely with air even if turned upside down. It can be proved with a simple experiment in which an empty bottle is turned upside down in a beaker filled with water. The water does not enter the bottle when it is pushed’in an inverted position because there is no space for air to escape. When the bottle is tilted, the air is able to escape out in the form of bubbles and water fills up the empty space. This shows that even an empty glass is filled with the air.
(d) Air contains some gases, water vapour and dust particles. When air is inhaled through nostrils, the fine hair and mucus present in the nose prevent dust particles from entering the respiratory tract. But, if we breathe through mouth, the harmful dust particles may enter our body and make us ill. Thus, breathing through mouth may harm us.

Question 18.
Write just a few sentences for an imaginary situation if any of the following gases disappear from the atmosphere.
(a) Oxygen
(b) Nitrogen
(c) Carbon dioxide
Solution:
(a) If oxygen gas disappeared from the atmosphere, life would not be possible on earth as the presence of oxygen is essential for the survival of the living organisms. Animals and plants take in oxygen from the atmosphere and release carbon dioxide during respiration. Even the aquatic plants and animals take up oxygen in the dissolved form for breathing. It would not be possible for organisms to breathe in the absence of oxygen and hence, eventually the organisms will die.
(b) Nitrogen constitutes major part i.e. 78% of the atmosphere and it does not support burning. If nitrogen gas disappeared from the atmosphere, things on earth will bum very fast which may produce disastrous results. Moreover, nitrogen is required by plants for their growth, although plants are not able to absorb the nitrogen directly from the air. They ocnsume it in the soluble form either through fertilisers or by converting it into nitrate compounds which are absorbed by the plants through soil. Nitrogen is also present in some amounts in all the proteins. All living things need protein for their growth. Thus, if nitrogen gets disappeared from the atmosphere, plants, animals, humans and other organisms would not be able to grow properly and may eventually die.
(c) Although carbon dioxide is present in traces (0.03%) in the atmosphere, it plays a major role in the survival of living beings. Plants require carbon dioxide to manufacture their own food by the process of photosynthesis. During this process, oxygen in evolved out. This maintains the carbon dioxide oxygen balance in the air. If carbon dioxide gets disappeared from the atmosphere, the plants will not be able to produce their food and oxygen will not be released which will disturb the carbon dioxide – oxygen ratio in the atmosphere. In the absence of oxygen and food, there will be no life on earth.

Question 19.
Paheli kept some water in a beaker for heating. She observed that tiny bubbles appeared before the water started to boil. She boiled the water for about 5 minutes and filled it in a bottle up to the brim and kept the bottle air tight till it cooled down to room temperature.
(a) Why did the tiny bubbles appeared?
(b) Do you think tiny bubbles will appear on heating the water taken out from the bottle? Justify your answer.
Solution:
(a) The tiny bubbles appeared before the water started to boil due to the air dissolved in water. On heating, the air dissolved in water escaped in the form of bubbles.
(b) The tiny bubbles will appear on heating the water taken out from the bottle as on opening the cap, some amount of air will be trapped in it. Some amount of air will also be trapped during the transfer of water from the bottle to the utensil for heating. Since the amount of trapped air will be less in the poured water, there will be less number of bubbles appearing in the water on heating as compared to the previous one.

Question 20.
On a Sunday morning Paheli’s friend visited her home. She wanted to see some flowering plants in the nearby garden. Both of them went to the garden. While returning from the garden they also observed some flowering plants on the road side. But to their surprise they found that the leaves and flowers of these roadside plants were comparatively very dull. Can you help them to know why?
Solution:
The dull appearance of the leaves and flowers of the roadside plants may be due to the djust and soot particles emitted from the vehicles, chimneys and factories. These particles might have got deposited on the plant parts which made them appear dull.

We hope the NCERT Exemplar Class 6 Science Chapter 15 Air Around Us will help you. If you have any query regarding NCERT Exemplar Class 6 Science Solutions Chapter 15 Air Around Us, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets

NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 13 Fun with Magnets.

NCERT Exemplar Class 6 Science Solutions Chapter 13 Fun with Magnets

Multiple Choice Questions 

Question 1.
Observe the pictures A and 8 given in figure carefully.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-1
Which of the following statement is correct for the above given pictures?
(a) In A, cars 1 and 2 will come closer and in B, cars 3 and 4 will come closer.
(b) In A, cars 1 and 2 will move away from each other and in B, cars 3 and 4 will move away.
(c) In A, cars 1 and 2 will move away and in 8,3 and 4 will come closer to each other.
(d) In A, cars 1 and 2 will come closer to each other and in 8,3 and 4 will move away from each other.
Solution:
(d) Unlike poles attract each other while like poles repel each other.

Question 2.
The arrangement to store two magnets is shown by figures (a), (b), (c) and (d). Which one of them is the correct arrangement?
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-2
Solution:
(b)

Question  3.
Three magnets A, B and C were dipped one by one in a heap of iron filing. Figure shows the amount of the iron filing sticking to them.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-3
The strength of these magnets will be
(a) A > B > C
(b) A < B < C
(c) A = B = C
(d) A < B > C
Solution:
(a): The amount of the iron filing sticking to magnets is directly proportional to their strengths.

Question 4.
North pole of a magnet can be identified by
(a) Another magnet having its poles marked as North pole and South pole.
(b) Another magnet no matter whether the poles are marked or not.
(c) Using an iron bar.
(d) Using iron filings.
Solution:
(a): That pole of the magnet which is repelled by the north pole of the given magnet will be considered as north pole of the magnet.

Question 5.
A bar magnet is immersed in a heap of iron filings and pulled out. The amount of iron filing clinging to the
(a) North pole is almost equal to the south pole.
(b) North pole is much more than the south pole.
(c) North pole is much less than the south pole.
(d) Magnet will be same all along its length.
Solution:
(a): Magnetic strengths of north pole and south pole of a magnet is same.

Very Short Answer Type Questions

Question 6.
Fill in the blanks.
(i) When a bar magnet is broken; each of the broken part will have _________ pole/poles.
(ii) In a bar magnet, magnetic attraction is _____ near its ends.
Solution:
(i) two
(ii) more

Question 7.
Paheli and her friends were decorating the class bulletin board. She dropped the box of stainless steel pins by mistake. She tried to collect the pins using a magnet. She could not succeed. What could be the reason for this?
Solution:
The pins are made of stainless steel which is a non-magnetic material.

Question 8.
How will you test that ‘tea dust’ is not adulterated with iron powder?
Solution:
By using a magnet we can test that tea dust’ is not adulterated with iron powder. If it has iron powder it will stick to the magnet.

Question 9.
Boojho dipped a bar magnet in a heap of iron filings and pulled it out. He found that iron filings got stuck to the magnet as shown in figure.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-4
(i) Which regions of the magnet have more iron filings sticking to it?
(ii)What are these regions called?
Solution:
(i) The ends of the magnet have more iron filings attached to it.
(ii) These regions are called poles of the magnet.

Short Answer Type Questions

Question 10.
Four identical iron bars were dipped in a heap of iron filings one by one. Figure shows the amount of iron filings sticking to each of them.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-5
(a) Which of the iron bar is likely to be the strongest magnet?
(b) Which of the iron bars is not a magnet? Justify your answer.
Solution:
(a) Iron bar (a) is likely to be the strongest magnet as amount of iron filings sticking to it, is much more than other bars.
(b) Iron bar (b) is not a magnet because iron filings do not stick to it.

Question 11.
A toy car has a bar magnet laid hidden inside its body along its length. Using another magnet i how will you find out which pole of the magnet is facing the front of the car?
Solution:
If the front of the toy car gets attracted to the north pole of the given magnet then it is the south pole of the bar magnet hidden inside the car and vice-versa.

Question 12.
Match column I with column II (One option of I can match with more than one option of II.

Column 1 Column II
(a) Magnet attracts (i) rests along a particular direction
(b) Magnet can be repelled by (ii) iron
(c) Magnet if suspended freely (iii) another magnet
(d) Poles of the magnet can be identified by (iv) iron filings

Solution:
(a) – (ii) , (iii) and (iv)
(b) – (iii)
(c) – (i)
(d) – (iii)

Question 13.
You are provided with two identical metal bars. , One out of the two is a magnet. Suggest two ways to identify the magnet.
Solution:
There can be following ways to identify the magnet out of the two identical metal bars :
(i) By freely suspending the metal bars. Magnet will rest along a particular direction.
(ii) By attracting iron filings.
(iii) By using another magnet. Like poles will repel each other while unlike poles will attract each other.

Long Answer Type Questions

Question 14.
Three identical iron bars are kept on a table. Two out of three bars are magnets. In one of the magnet the North-South poles are marked. How will you find out which of the other two bars is a magnet? Identify the poles of this magnet.
Solution:
The magnet on which the North-South poles are marked can be used to find out the magnet out of two bars.
The magnet with known poles will attract and repel two ends of a magnet while it will attract both the ends of an ordinary bar. This process is known as test for repulsion. To find out the poles of unknown magnet, we can use the same test. North pole marked on the given magnet will repel the north pole of unknown magnet.

Question 15.
Describe the steps involved in magnetising an iron strip with the help of a magnet.
Solution:
An iron strip can be magnetised by rubbing it with a magnet in a particular direction again and again as shown in figure.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-6
Magnets can also be made with the help of electricity.

Question 16.
Figure shows a magnetic compass. What will happen to the position of its needle if you bring a bar magnet near it? Draw a diagram to show the effect on the needle on bringing the bar magnet near it. Also draw the diagram to show the effect when the other end of the bar magnet is brought near it.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-7
Solution:
The magnetic needle of the compass will get deflected.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-8

Question 17.
Suggest an activity to prepare a magnetic compass by using an iron needle and a bar magnet.
Solution:
To prepare a magnetic compass, the given iron needle is magnetised by rubbing a bar magnet over it repeatedly in a particular direction. After that it may be set in a way so that it can rotate freely when suspended. Hence, the iron needle can act as compass and give north-south direction.

Question 18.
Boojho kept a magnet close to an ordinary iron bar. He observed that the iron bar attracts a pin as shown in figure.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-9
What inference could he draw from this observation? Explain.
Solution:
He could infer from this observation that the magnetic properties are induced into the iron bar and it acts like a magnet till the magnet is kept near it.

Question 19.
A bar magnet is cut into two pieces A and B, from the middle, as shown in figure.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-10
Will the two pieces act as individual magnets? Mark the poles of these two pieces. Suggest an activity to verify your answer.
Solution:
Yes, the two pieces A and B will act as individual magnets. A magnet will always have two poles – north and south pole. Each piece will have two poles.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-11
By the test of repulsion, we can conclude that these two pieces A and B will act as individual magnets.

Question 20.
Suggest an arrangement to store a U shaped magnet. How is this different from storing a pair of bar magnets?
Solution: U shaped magnet – One metal plate is placed across the two poles of the U shaped magnet to store it.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-12
Bar magnet – Two metal plates and one wooden block is used and arranged as shown in the figure.
NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets img-13

We hope the NCERT Exemplar Class 6 Science Chapter 13 Fun with Magnets will help you. If you have any query regarding NCERT Exemplar Class 6 Science Solutions Chapter 13 Fun with Magnets, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits

NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 12 Electricity and Circuits.

NCERT Exemplar Class 6 Science Solutions Chapter 12 Electricity and Circuits

Multiple Choice Questions

Question 1.
Choose from the options a, b, c and d given in the figure which shows the correct direction of current .
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-1
Solution:
(b): In an electric circuit, the direction of current is taken to be from the positive terminal to the negative terminal of the electric cell.

Question 2.
Choose the incorrect statement.
(a) A switch is the source of electric current in a circuit.
(b) A switch helps to complete or break the circuit.
(c) A switch helps us to use electricity as per our requirement.
(d) When the switch is open there is an air gap between its terminals.
Solution:
(a) : An electric cell is the source of electric current in a circuit.

Question 3.
In an electric bulb, light is produced due to the glowing of
(a) the glass case of the bulb
(b) the thin filament
(c) the thick wires supporting the filament
(d) gases inside glass case of the bulb.
Solution:
(b)

Question 4.
In the following arrangement shown in figure, the bulb will not glow if the ends A and B are connected with
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-2
(a) A steel spoon
(b) A metal clip
(c) A plastic clip
(d) A copper wire
Solution:
(c): Plastic clip is an insulator. It does not conduct electricity.

Question 5.
In the circuit shown in figure, when the switch is moved to’ON’ position,
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-3
(a) the bulb A will glow first
(b) the bulb B will glow first
(c) the bulb C will glow first
(d) all bulbs will glow together.
Solution:
(d): As soon as the circuit gets completed, current is found at every point in the circuit instantly.

Question 6.
Filament of a torch bulb is
(a) a metal case
(b) metal tip at the centre of the base
(c) two thick wires
(d) a thin wire.
Solution:
(d)

Question 7.
Paheli is running short of connecting wires. To complete an electric circuit, she may use a
(a) glass bangle
(b) thick thread
(c) rubber pipe
(d) steel spoon.
Solution:
(d): Steel spoon is a good conductor of electricity.

Question 8.
In which of the following circuits A, B and C given in figure, the cell will be used up very rapidly?
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-4
Solution:
In circuit A, the cell will be used up very rapidly.

Question 9.
Figure shows a bulb with its different parts marked as 1,2,3,4 and 5. Which of them label the terminals of the bulb?
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-5
Solution:
Labels 3 and 4 are the terminals of the bulb.

Short Answer Type Questions

Question 10.
You are provided with a bulb, a cell, a switch and some connecting wires. Draw a diagram to show the connections between them to make the bulb glow.
Solution:
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-6

Question 11.
Will the bulb glow in the circuit shown in figure ? Explain.
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-7
Solution:
No, the bulb will not glow in this circuit because the switch is open and the circuit is incomplete. Current flows only in a closed circuit.

Question 12.
An electric bulb is connected to a cell through a switch as shown in figure. When the switch is brought in ‘ON’ position, the bulb does not glow. What could be the possible reason/s for it? Mention any two of them.
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-8
Solution:
There could be following reasons for it:
(i) Cell is a used one.
(ii) Bulb is fused.
(iii) Loose connections.
(iv) Break in connecting wires.

Question 13.
A torch requires 3 cells. Show the arrangement of the cells, with a diagram, inside the torch so that the bulb glows.
Solution:
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-9

Question 14.
When the chemicals in the electric cell are used up, the electric cell stops producing electricity. The electric cell is then replaced with a new one. In case of rechargeable batteries (such – as the type used in mobile phones, camera and inverters), they are used again and again. How?
Solution:
Rechargeable batteries can be recharged • by providing them appropriate current. These are called secondary cells or storage cells.

Question 15.
Paheli connected two bulbs to a cell as shown f in figure,
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-10
She found that filament of bulb B is broken. Will the bulb A glow in this circuit? Give reason.
Solution:
No, the bulb will not glow in this circuit as the filament of bulb B is broken. So the circuit remains incomplete.

Question 16.
Why do bulbs have two terminals?
Solution:
Bulb consists of a tiny thin wire called filament. Bulb has two terminals to connect the filament within the circuit so that current can pass through it.

Question 17.
Which of the following arrangement A, B, C and D given in figure should not be set up? Explain, why?
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-11
Solution:
Arrangement A is not desirable and should not be set up. This will exhaust the cell very quickly as large current will flow through it.

Question 18.
A fused bulb does not glow. Why?
Solution:
In a fused bulb, the filament is broken and the circuit is incomplete.

Question 19.
Paheli wanted to glow a torch bulb using a cell. She could not get connecting wires, instead, she got two strips of aluminium foil. Will she succeed? Explain, how?
Solution:
Yes, she will succeed as aluminium foil strips can act as connecting wires being good conductor of electricity.

Long Answer Type Questions

Question 20.
Boojho has a cell and a single piece’ of connecting wire. Without cutting the wire in two, will he be able to make the bulb glow? Explain with the help of a circuit diagram.
Solution:
Yes, using the arrangement given in figure, he can succeed in getting the bulb glow.
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-12
He can connect second terminal of the bulb directly to the positive terminal of the cell as given in figure. In this way, circuit will get completed without using another piece of connecting wire.

Question 21.
Figure A and B, show a bulb connected to a cell in two different ways.
NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits img-13
(i) What will be the direction of the current through the bulb in both the cases (Q to P orPto Q)?
(ii) Will the bulb glow in both the cases?
(iii) Does the brightness of the glowing bulb depend on the direction of current through it?
Solution:
(i) In case A: Q toP
In case B: P to Q
(ii) Yes, the bulb will glow in both the cases as the circuit is complete in both the cases.
(iii) No, the brightness of the glowing bulb does not depend on the direction of current through it.

Question 22.
Think of six activities which use electric current. Also name the devices used to perform the activity.
Example:

Activity you perform get light Device Torch

Solution:

Activity you perform Device
(i) Get light Torch
(ii) Heat water Geyser/ immersion rod
(iii) Make toast Toaster
(iv) Cook food Heater/microwave
(v) Listen to music CD player/ radio/i-pod
(vi) Watch movies TV/Laptop

Question 23.
A torch is not functioning, though contact points in the torch are in working condition. What can be the possible reasons for this? Mention any three.
Solution:
The possible reasons could be
(i) the bulb may be fused.
(ii) the cells may have been used up.
(iii) the cells are not placed in the correct order.
(iv) the switch is faulty.

We hope the NCERT Exemplar Class 6 Science Chapter 12 Electricity and Circuits will help you. If you have any query regarding NCERT Exemplar Class 6 Science Solutions Chapter 12 Electricity and Circuits, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections

NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 11 Light, Shadows and Reflections.

NCERT Exemplar Class 6 Science Solutions Chapter 11 Light, Shadows and Reflections

Multiple Choice Questions

Question 1.
Observe the picture given in figure carefully.
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-1
A patch of light is obtained at B, when the torch is lighted as shown. Which of the following is kept at position A to get this patch of light?
(b) A glass sheet
(c) A mirror
(d) A sheet of white paper,
Solution:
Only a mirror can reflect a patch of light and change its direction.

Question 2.
A student observes a tree given in figure through a pinhole camera. Which of the diagrams given in figures (a) to (d), depicts the image seen by her correctly?
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-2
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-3
Solution:
(b:) She will observe upside down image of the tree with lateral inversion.

Question 3.
Four students A, B, C and D looked through pipes of different shapes to see a candle flame as shown in figure.
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-4
Who will be able to see the candle flame clearly?
(a) A
(b) B
(c) C
(d) D
Solution:
(d): Light travels in a straight line.

Question 4.
Which of the following is/are not always necessary to observe a shadow?
(a) Sun
(b) Screen
(c) Source of light
(d) Opaque object
Solution:
(a): Sun is a source of light. Any source of light can replace it. So, sun is not always necessary to observe a shadow.

Question 5.
Paheli observed the shadow of a tree at 8:00 a.m., 12:00 noon and 3:00 p.m. Which of the following statements is closest to her observation about the shape and size of the shadow?
(a) The shape of the shadow of the tree changes but the size remains the same.
(b) The size of the shadow of the tree changes but the shape remains the same.
(c) Both the size and shape of the shadow of the tree change.
(d) Neither the shape nor the size of the shadow changes.
Solution:
(c): Sun is source of light here and it changes its position at different points of time. So accordingly size and shape of the shadow of the tree change.

Question 6.
Which of the following can never form a circular shadow?
(a) A ball
(b) A flat disc
(c) A shoe box
(d) An ice cream cone
Solution:
(c)

Question 7.
Two students while sitting across a table looked down on to its top surface. They noticed that they could see their own and each other’s image. The table top is likely to be made of
(a) unpolished wood
(b) red stone
(c) glass sheet
(d) wood top covered with cloth
Solution:
(c): Out of the given options, only glass sheet can reflect light properly in order to form their images.

Very Short Answer Type Questions

Question 8.
You have 3 opaque strips with very small holes of different shapes as shown in figure. If you obtain an image of the sun on a wall through these holes, will the image formed by these holes be the same or different?
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-5
Solution:
Same image will be formed by these holes. These opaque strips will act as pinholes and image of the sun will be obtained on wall.

Question 9.
Observe the picture given in figure. A sheet of some material is placed at position ‘P’, still the patch of light is obtained on the screen. What is the type of material of this sheet?
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-6

Solution:
Sheet P must be of transparent material as it allows light to pass through it.

Question 10.
Three torches A, B and C shown in figure are switched on one by one. The light from which of the torches will not form a shadow of the ball on the screen.
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-7
Solution:
The light from torch C will not form a shadow of the ball on the screen. Torch C is parallel to the screen and light travels in straight line.

Question 11.
Look at the given figure.
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-8
Will there be any difference in the shadow formed on the screen in A and B ?
Solution:
No, shadows formed on the screens A and B will be same.

Question 12.
Correct the following statements.
(i) The colour of the shadow of an object depends on its colour of the object.
(ii) Transparent objects allow light to pass through them partially.
Solution:
(i) The colour of the shadow of an object does not depend on its colour of the object.
(ii) Translucent objects allow light to pass through them partially or transparent objects allow most of the light to pass through them.

Question 13.
Suggest a situation where we obtain more than one shadow of an object at a time.
Solution:
At a time we can obtain more than one shadow of an object if light from more than one source falls on it.
For example: While watching a match in a stadium, we can observe multiple shadows of players.

Question 14.
0n a sunny day, does a bird or an aeroplane flying high in the sky cast its shadow on the ground? Under what circumstances can we see their shadow on the ground?
Solution:
Even on a sunny day, a bird or an aeroplane flying high in the sky does not cast its shadow on the ground.
We can see their shadow on the ground only if they are flying very close to the ground. In this case, ground acts as screen.

Question 15.
You are given a transparent glass sheet. Suggest any two ways to make it translucent without breaking it.
Solution:
(i) By applying oil, grease, butter on it or pasting a butter paper on it.
(ii) Grinding (rubbing) the surface of the glass by any abrasive material.

Question 16.
A torch is placed at two different positions A and B, one by one, as shown in figure.
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-9
The shape of the shadow obtained in two positions is shown in figure.
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-10
Match the position of the torch and shape of the shadow of the ball.
Solution:
A  → a; B → b
As the position of torch changes, we can observe the change in shape of shadow.

Question 17.
A student covered a torch with red cellophane sheet to obtain red light. Using the red light she obtains a shadow of an opaque object. She repeats this activity with green and blue light. Will the colour of the light affect the shadow? Explain.
Solution:
Maim The colour of light will not affect the shadow because shadow is the dark patch r formed when an object obstructs the path of
light and hence no light reaches in the shadow region.

Question 18.
Is air around us always transparent? Discuss.
Solution:
Mann Air around us is transparent but when thick smoke/ thick clouds, etc. are present in ‘ the air it does not remain transparent.

Question 19.
Three identical towels of red, blue and green colour are hanging on a clothesline in the sun. ‘ What would be the colour of shadows of these
towels?
Solution:
The colour of shadows of all the three t towels will be same as no light passes through them. Shadow will be of black colour.

Question 20.
Using a pinhole camera a student observes the image of two of his friends, standing in sunlight, wearing yellow and red shirt respectively. What will be the colours of the shirts in the image?
Solution:
The colours of the image of the shirts 1 will be the same as the colour of the shirt. Image obtained using a pinhole camera is inverted.

Question 21.
In figure, a flower made of thick coloured paper has been pasted on the transparent glass sheet.What will be the shape and colour of shadow seen on the screen?
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-11
Solution:
The shadow formed will be dark and of the shape of the flower along with the stalk.

Long Answer Type Questions

Question 22.
A football match is being played at night in a stadium with flood lights ON. You can see the shadow of a football kept at the ground but cannot see its shadow when it is kicked high in the air. Explain.
Solution:
We can see the shadow of football lying on the ground because the ground acts as a screen for it. However, when the football is kicked high, the ground, which is acting as a screen is away from the football, hence no shadow of the football will be formed on the ground.

Question 23.
A student had a ball, a screen and a torch in working condition. He tried to form a shadow of the ball on the screen by placing them at different positions. Sometimes the shadow was not obtained. Explain.
Solution:
Some of the reason can be
(i) The screen is far away from the ball.
(ii) The beam of light from the torch is falling parallel to the screen on the ball.
(iii) The torch is kept away from the ball.

Question 24.
A sheet of plywood, a piece of muslin cloth and that of a transparent glass, all of the same size and shape were placed at A one by one in the arrangement shown in figure. Will the shadow be formed in each case. If yes, how will the shadow on the screen be different in each case? Give reasons for your answer.
NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections img-12
Solution:
Shadow will not be formed in each case. Only the piece of muslin cloth and the sheet of plywood will cast shadow on the screen.
The sheet of plywood will form a dark shadow as it blocks the path of light completely. The piece of muslin cloth will form a lighter shadow as it allows light to pass through it partially. The transparent glass will allow most of the light to pass through it. So, no shadow will be obtained on screen.

We hope the NCERT Exemplar Class 6 Science Chapter 11 Light, Shadows and Reflections will help you. If you have any query regarding NCERT Exemplar Class 6 Science Solutions Chapter 11 Light, Shadows and Reflections, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement

NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement of Distances are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 10 Motion and Measurement of Distances.

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

Multiple Choice Questions

Question 1.
The distance between Delhi and Mumbai is usually expressed in units of
(a) decametre
(b) metre
(c) centimetre
(d) kilometre
Solution:
(d) : The distance between Delhi and Mumbai is very large so it is usually expressed in units of kilometre.

Question 2.
Which of the following does not express a time interval?
(a) A day
(b) A second
(c) A school period
(d) Time of the first bell in the school
Solution:
(d): Time of the first bell in the school represents a point of time, not a time interval.

Question 3.
Figure shows a measuring scale which is usually supplied with a geometry box. Which of the following distance cannot be measured with this scale by using it only once?
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-1
(a) 0.1m
(b) 0.15 m
(c) 0.2 m
(d) 0.05 m
Solution:
(c): This scale is 0.15 m long so by using it only once, 0.2 m cannot be measured.

Question 4.
A piece of ribbon folded five times is placed along a 30 cm long measuring scale as shown in figure.
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-2
The length of the ribbon is between
(a) 1.15 m – 1.25 m
(b) 1.25 m – 1.35 m
(c) 1.50 m – 1.60 m
(d) 1.60 m – 1.70 m.
Solution:
(b): According to the given figure, the five times folded ribbon piece is (27.5 – 2) cm x 5 (= 1.275 m) long approximately.

Question 5.
Paheli moves on a straight road from point A to point C. She takes 20 minutes to cover a certain distance AB and 30 minutes to cover the rest of distance BC. She then turns back and takes 30 minutes to cover the distance CB and 20 minutes to cover the rest of the distance to her starting point. She makes 5 rounds on the road the same way. Paheli concludes that her motion is
(a) only rectilinear motion
(b) only periodic motion
(c) rectilinear and periodic both.
(d) neither rectilinear nor periodic
Solution:
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-3
Paheli is moving along a straight line with a fixed time period. So, her motion is rectilinear and periodic both.

Question 6.
Bholu and Golu are playing in a ground. They start running from the same point A in the ground and reach point B at the same time by following the paths marked 1 and 2 respectively as shown in figure. Which of the following is/are true for the given situation ?
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-4
As compared to Golu, Bholu covers a
(a) longer distance but with a lower speed
(b) longer distance with a higher speed
(c) shorter distance with a lower speed
(d) shorter distance with a higher speed.
Solution:
(b) : Path 1 is longer than path 2 but Golu and Bholu both have reached point B at the same time, so Bholu’s speed is more than Golu’s speed.

Question 7.
Four pieces of wooden sticks A, B, C and D are placed along the length of 30 cm long scale as shown in figure. Which one of them is 3.4 cm in length?
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-5
(a) A
(b) B
(c) C
(d) D
Solution:
From the given figure, we can observe that stick C lies between 10.4 cm and 7 cm. So, its length is (10.4 – 7) cm = 3.4 cm.

Question 8.
Which of the following figure shows the correct placement of a block along a scale for measuring its length?
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-6

NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-7
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-8
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-9

Solution:
(c): Object should be placed on a scale such that its ends should come in between the readings marked on the scale.

Question 9.
You are provided three scales A, B and C as shown in figure to measure a length of 10 cm.
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-10
For the correct measurement of the length you will use the scale
(a) A only
(b) B only
(c) C only
(d) Any of the three Scales.
Solution:
(d): Length of 10 cm is available in all the three scales A, B and C. So, any of the three scales’ can be used.
Correct the following.

Question 10.
(i) The motion of a swing is an example of rectilinear motion.
(ii) 1m = 1000cm
Solution:
(i) The motion of a swing is an example of periodic motion as it repeats its motion after a fixed interval of time.
(ii) 1 m = 100 cm. Each metre (m) is divided into 100 equal divisions, called centimetre (cm).

Question 11.
Fill in the blanks.
(i) Motion of an object or a part of it around a fixed point is known as_______ motion.
(ii) A body repeating its motion after certain interval of time is in_______ motion.
(iii) In rectilinear motion, object moves a______ line______.
(iv) SI unit of length is_______.
Solution:
(i) Circular
(ii) periodic
(iii) along; straight
(iv) metre

Question 12.
Write one example for each of the following type of motion.
(i) Rectilinear
(ii) Circular
(iii) Periodic
(iv) Circular and periodic
Solution:
(i) An apple falling vertically downwards.
(ii) The motion of a point marked on the hands of a clock.
(iii) Motion of a child on a swing.
(iv) Blades of a rotating fan.

Short Answer Type Questions

Question 13.
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-11
The photograph given in figure shows a section of a grille made up of straight and curved iron bars. How would you measure the length of the bars of this section, so that the payment could be made to the contractor?
Solution:
As the grille is made up of straight and curved iron bars, so the length of the bars can be measured with the help of thread which can be further measured using a scale.

Question 14.
Identify the different types of motion in the following word diagram given.

Y O U N G C C N T E R
L E V E L p I E E A R
A L L O T o P P E A I
N O T E P A D N E C K
O W O N E w I Y Z s E
I E V O R L O A D w P
T R G N I C E D R I L
A Z H T O N G U E N A
T X C R D E P T H G R
O E Y C I R C U L A R
R T L C C O P P E R T

Solution:
NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement img-12

Question 15.
Four children measure the length of a table which was about 2 m. Each of them used different ways to measure it.
(i) Sam measured it with a half metre long thread.
(ii)with a 15 cm scale from her geometry box.
(iii) Reena measured it using her hand span.
(iv) Salim measured it using a 5 m long measuring tape.
Which one of them would get the most accurate length? Give reason for your answer.
Solution:
Salim would get the most accurate length because’ he is using a 5 m long measuring tape which is longer than the table. So, he can measure the length of the table in one go accurately. While in the other cases the chance of making an error is higher due to multiple measurements. In case of Sam, only that lengths can be measured which are exact multiples of half a metre.

Question 16.
Match the events related to motion in column I with the types of motions given in column II.

Column 1 Column 11
(a) A moving wheel of a sewing machine (i) Circular motion
(b) Movement of tip of the minute hand of a clock in one hour (ii) Rotational motion
(0 A moving swing (iii) Periodic motion

(a) – (ii)
(b) – (i)
(c) – (iii)

Long Answer Type Questions

Question 17.
While travelling in a train, it appears that the trees near the track are moving whereas co-passengers appear to be stationary. Explain the reason.
Solution:
While sitting in a moving train, when we look outside the window, the trees appear to be moving in opposite direction because their position is changing with respect to us. On the other hand the position of co-passengers is not changing with respect to us, hence they appear to be stationary.

Question 18.
How are the motions of a wheel of a moving bicycle and a mark on the blade of a moving electric fan different? Explain.
Solution:
The wheel of a moving bicycle depicts circular as well as rectilinear motion. Wheels of bicycle rotate on the ground which in turn moves the bicycle forward. A blade of a moving electric fan shows only circular motion as it is not moving from one place to another.

Question 19.
Three students measured the length of a corridor and reported their measurements. The values of their measurements were different.
What could be the reason for difference in their measurements? (Mention any three)
Solution:
Some of the reasons for difference in their measurement could be
(i) Different measuring devices were used.
(ii) The smallest length that could be _ measured by different devices may be different.
(iii) Measurement may not be along the shortest length in all three cases.
(iv) The end of the corridor may not be easily accessible.
(v) The measuring devices may be faulty (not standardised).

Question 20.
Boojho was riding in his bicycle along a straight road. He classified the motion of various parts of the bicycle as
(i) rectilinear motion,
(ii) circular motion and
(iii) both rectilinear as well as circular motion. Can you list one part of the bicycle for each type of motion? Support your answer with reason.
Solution:
(i) Rectilinear motion: Handle bar or seat of the bicycle has rectilinear motion only. It moves in a straight line as the wheels of bicycle move forward.
(ii) Circular motion: Pedal of the bicycle is having circular motion only as it rotates with its shaft but does not move from its place.
(iii) Rectilinear and circular motion: Wheel of the bicycle is having both circular and rectilinear motion. Wheels rotate on their ‘ shafts as well as move forward on the ground.

We hope the NCERT Exemplar Class 6 Science Chapter 10 Motion and Measurement of Distances will help you. If you have any query regarding NCERT Exemplar Class 6 Science Solutions Chapter 10 Motion and Measurement of Distances, drop a comment below and we will get back to you at the earliest.

NCERT Exemplar Class 6 Science Chapter 6 Changes around Us

NCERT Exemplar Class 6 Science Chapter 6 Changes around Us are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 6 Changes around Us.

NCERT Exemplar Class 6 Science Solutions Chapter 6 Changes around Us

Multiple Choice Questions

Question 1.
Pick the change that can be reversed from the following.
(a) Cutting of trees
(b) Melting of ghee
(c) Burning of candle
(d) Blooming of flower
Solution:
(b): The molten ghee can be frozen again hence this change can be reversed. Cutting of trees, burning of candle and blooming of flower cannot be reversed.

Question 2.
Which of the following change cannot be reversed?
(a) Hardening of cement
(b) Freezing of ice cream
(c) Opening a door
(d) Melting of chocolate
Solution:
(a): Hardening of cement is irreversible because once hardened it cannot come back to its original shape.

Question 3.
An iron ring is heated. Which of the following statement about it is incorrect?
(a) The ring expands.
(b) The ring almost comes to the same size on cooling.
(c) The change in this case is reversed.
(d) The ring changes its shape and the change cannot be reversed.
Solution:
(d) : The ring expands on heating and comes back to its original size on cooling. The change is reversible.

Question 4.
While lighting a candle, Paheli observed the following changes.
(i)Wax was melting
(ii)Candle was burning
(iii)Size of the candle was reducing
(iv)Melted wax was getting solidified. of the above, the changes that can be reversed are
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Solution:
(d): Molten wax solidifies and the solid wax can be again melted. Hence melting of wax and its solidification are reversible changes.

Question 5.
Salt can be separated from its solution (salt dissolved in water), because
(a) mixing of salt in water is a change that can be reversed by heating and melting of salt
(b) mixing of salt in water is a change that cannot be reversed
(c) mixing of salt in water is a permanent ‘ change
(d) mixing of salt in water is a change that can be reversed by evaporation.
Solution:
(d): Salt can be separated from its water solution by evaporating the water. Hence mixing of salt in water is a reversible change.

Question 6.
Rolling of chapati and baking of chapati are the changes that
(a) can be reversed
(b) cannot be reversed
(c) can be reversed and cannot be reversed, respectively
(d) cannot be reversed and can be reversed, respectively.
Solution:
(c) : Rolling of chapati is a physical reversible change because there is no change in the properties of kneaded flour. Once the chapati is baked it cannot be reversed.

Question 7.
Iron rim is made slightly smaller than the wooden wheel. The rim is usually heated before fixing into the wooden wheel, because on heating the iron rim
(a) expands and fits onto the wooden wheel
(b) contracts and fits onto the wooden wheel
(c) no change in the size takes place
(d) expands first, then on cooling contracts and fits onto the wooden wheel.
Solution:
(d) : The smaller iron rim expands on heating fits into the wooden wheel and on cooling contracts to fit into the wooden wheel tightly hence does not come out.

Very Short Answer Type Questions

Question 8.
Look at figure 6.1 which shows three situations
(a) a burning candle
(b) an extinguished candle
(c) melting wax.
NCERT Exemplar Class 6 Science Chapter 6 Changes around Us img-1
Which of these shows a reversible change and why?
Solution:
Melting of wax in the figure (c) is a reversible change because the molten wax can be solidified again.

Question 9.
A piece of iron is heated till it becomes red-hot. it then becomes soft and is beaten to a desired shape. What kind of changes are observed in this process-reversible or irreversible?
Solution:
A piece of iron on heating can be beaten into desired shape. It is a reversible change because the object of desired shape can be again heated and beated to give the original shape.

Question 10.
Paheli had bought a new bottle of pickle from the market. She tried to open the metal cap to taste it but could not do so. She then took a bowl of hot water and immersed the upper end of the bottle in it for five minutes. She could easily open the bottle now. Can you give the reason for this?
Solution:
On immersing in hot water, the metal cap expands in size hence it can be removed easily.

Short Answer Type Questions

Question 11.
Can we reverse the following changes? If yes, suggest the name of the method.
(a) Water into water vapour
(b) Water vapour into water
(c) Ice into water
(d) Curd into milk.
Solution:
(a) Water into water vapour – Yes, by condensation water vapour can be converted to water.
(b) Water vapour into water – Yes, water can be converted to water vapour by evaporation.
(c) Ice into water – Yes, water can be converted to ice by freezing.
(d) Curd into milk is an irreversible process.

Question 12.
Which of the following changes cannot be reversed?
(a) Blowing of a balloon
(b) Folding a paper to make a toy aeroplane
(c) Rolling a ball of dough to make roti
(d) Baking cake in an oven
(e) Drying a wet cloth
(f) Making biogas from cow dung
(g) Burning of a candle
Solution:
(a) Blowing of a ballon
(b) Folding a paper to make a toy aeroplane
(c) Rolling a ball of dough to make roti
(d) Baking of a cake is irreversible.
(e) Drying a wet cloth
(f) Making biogas from cow dung is irreversible.
(g) Burning of a candle is irreversible.

Question 13.
Boojho’s sister broke a white dove, a symbol of peace, made of Plaster of Paris (POP). Boojho tried to reconstruct the toy by making a powder of the broken pieces and then making a paste by mixing water. Will he be successful in his effort? Justify your answer.
Solution:
Boojho will not be successful because making of toy from Plaster of Paris (POP) is an irreversible change. Once the Plaster of Paris is mixed with water and dried it cannot regain its properties.

Question 14.
Tearing of paper is said to be a change that cannot be reversed. What about paper recycling?
Solution:
Recycling of paper cannot be classified as a reversible change because the quality, colour and texture of the paper changes on recycling and we get a different type of paper not the original one.

Long Answer Type Questions

Question 15.
(b) Change which occurs on heating but cannot be reversed.
(c) Change which occurs on cooling but can be reversed.
(d) Change which occurs on mixing two substances, but can be reversed.
(e) Change which occurs on mixing two substances, but cannot be reversed.
Solution:
(a) Heating of an iron rod
(b) Baking of chapati
(f) Formation of ice from water
(d) Formation of salt solution
(e) Mixing of cement with water

Question 16.
A potter working on his wheel shaped a lump of clay into a pot. He then baked the pot in an oven. Do these two acts lead to the same kind of changes or different? Give your opinion and justify your answer.
Solution:
The two acts lead to the different kind of changes. Shaping of pot on a wheel is a physical, reversible change while baking the pot in an oven is an irreversible change.

Question 17.
Conversion of ice into water and water into ice is an example of change which can be reversed. Give four more examples where you can say that the changes can be reversed.
Solution:
Examples of reversible changes
(i) Melting of wax
(ii) Folding of a paper
(iii) Inflating a tyre or balloon
(iv) Knitting of a sweater

Question 18.
Change of a bud into a flower is a change which cannot be reversed. Give four more such example.
Solution:
Examples of irreversible changes
(i) Milk into curd
(ii) Burning of wood
(iii) Ripening of fruits
(iv) Digestion of food

Question 19.
Paheli mixed flour and water and (i) made a dough, (ii) rolled the dough to make a chapati, (iii) baked the chapati on a pan, (iv) dried the chapati and ground it in a grinder to make powder. Identify the changes (i) to (iv) as the changes that can be reversed or that cannot be reversed.
Solution:
(i) Making of dough from flour and water is irreversible change.
(ii) Rolling the dough to make a chapati is reversible change.
(iii) Baking the rolled chapati on a pan is irreversible change.
(iv) Grinding of dried chapati in a grinder is irreversible change.

Question 20.
lt was Paheli’s birthday, her brother Simba was helping her to decorate the house for the birthday party and their parents were also busy making other arrangements. Following were the activities going on at Paheli’s home:
(i) Simba blew balloons and put them on the wall.
(ii) Some of the balloons got burst.
(iii) Paheli cut colourful strips of paper and put them on the wall with the help of tape.
(iv) She also made some flowers by origami (paper folding) to decorate the house.
(v) Her father made dough balls.
(vi) Mother rolled the dough balls to make puries.
(vii) Mother heated oil in a pan.
(viii) Father fried the puries in hot oil.
Identify the activities at Paheli’s home as those that can be reversed and those which cannot be reversed.
Solution:
Activities (i), (iv), (v), (vi) and (vii) can be reversed and rest cannot be reversed.

 

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NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants

NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 7 Getting to Know Plants.

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

Multiple Choice Questions

Question 1.
Which of the following combination of features would you observe in grass?
(a) Parallel venation and fibrous root
(b) Parallel venation and tap root
(c) Reticulate venation and fibrous root
(d) Reticulate venation and tap root
Solution:
(a): In parallel venation, veins run parallel to one another in the leaf. Fibrous roots are underground thin fibre like roots which arise in groups from the base of the stem. Parallel venation and fibrous roots are usually found in grass, maize, wheat etc.

Question 2.
Which of the following is the correct match between the characteristics of stem and the category of plant?
(a) Weak stem which cannot stand upright: Creeper
(b) Green tender stem: Shrub
(c) Thick, hard stem with branching near the base: Tree
(d) Thick, hard stem with branches high on the plant: Herb
Solution:
(a) : Herbs are the small sized plants with green, tender stem. Shrubs are the medium sized plants having thick, hard stem with branching near the base. Trees are the tall plants having thick, hard stem with branches high on the plant.

Question 3.
Which of the following is not the primary function of stem?
(a) Conduction of water
(b) Photosynthesis
(c) Formation of branches
(d) Bears flowers and fruits
Solution:
(b): Photosynthesis is the primary function of leaf.

Question 4.
Which of the following is not a correct match?
(a) Petiole: attaches leaf to stem
(b) Lamina: green flat part of leaf
(c) Margin: gives shape to the leaf
(d) Veins: transpiration
Solution:
(d) : Veins: Transpiration Veins transport water, minerals and food in the leaf, and provide support to the leaf.

Question 5.
Read the following sentences about photosynthesis.
(i) Sunlight, carbon dioxide, chlorophyll and water are necessary.
(ii) Oxygen is absorbed.
(iii) Leaves carry out photosynthesis.
(iv) Proteins are made during photosynthesis. Choose the correct pair of sentences that are true to photosynthesis.
(a) (iii) and (iv)
(b) (i) and (iii)
(c) (ii) and (iv)
(d) (i) and (iv)
Solution:
(b) : Oxygen is released during photosynthesis. Carbohydrates (glucose) are made during photosynthesis not proteins.

Question 6.
Which of the following terms constitute the female part of the flower?
(a) Sepals, petal and stamen
(b) Stigma, style and ovary
(c) Ovary, stamen and stigma
(d) Ovary, style and stamen
Solution:
(b): Carpel (pistil) is the female reproductive f part of a flower. It consists of stigma, style and ovary. Sepals and petals are accessory parts
and stamens are male reproductive parts of a flower.

Very Short Answer Type Questions

Question 7.
Fill in the blanks.
(a) The small green leaves at the base of flowers are known as _____.
(b) The swollen basal part of the____ pistil is the
which bears the ____.
(c) Stamen has two parts called_____ and ____.
(d) The young unopened flower is termed as______.
Solution:
(a) sepals
(b) ovary, ovules
(c) filament, anther
(d) bud.

Question 8.
Solve the riddles given below.
(a) “I have a green tender stem and I am much shorter than you. Who am I?”
(b) I come out first from the seed when it is soaked in water. I provide anchorage to plants. Who am I? Write another function that I perform.
Solution:
(a) : Herb – Herbs are the small plants with green and tender stem.
(b) Root comes out first from the seed when it is soaked in water. Another function of root is to absorb water and mineral from the soil.

Short Answer Type Questions

Question 9.
Match the parts of plant given in column I with their function in column II.

Column I Column II
(a) Flower (i) Excretion
(b) Leaf (ii) Photosynthesis
(c) Stem (iii) Reproduction
(d) Root (iv) Bears branches
(v) Anchorage

Solution:
(a)-(iii)
(b)-(ii)
(c)-(iv)
(d)(v)

Question 10.
Boojho wanted to test the presence of starch in leaves. He performed the following steps.
(1) He took a leaf and boiled it in water.
(2) He placed the leaf in a petri dish and poured some iodine over it.
He did not get the expected result. Which step did he miss? Explain.
Solution:
After boiling the leaf in water, it has to be boiled in alcohol so that chlorophyll is removed and the green colour of the leaf comes out. Boojho did not boil the leaf in spirit (alcohol) to remove the chlorophyll and therefore, he did not get the expected result (i.e. change in colour of the leaf).

Question 11.
Will a leaf taken from a potted plant kept in a dark room for a few days turn blue black when tested for starch? Give reasons for your answer.
Solution:
No, it will not turn blue black because all the starch stored in the leaf would have been used up by the plant and no starch would be synthesised in the leaves due to the non-availability of sunlight.

Question 12.
Can the stem of a plant be compared with a street with two-way traffic? Give reason.
Solution:
Yes. It is because in stem, water and mineral move in upward direction and food moves in downward direction. The stem conducts water and minerals from the root to leaves and other parts of the plant (upward). The food prepared by the leaves travels through the stem and is stored in different parts (downward).

Long Answer Type Questions

Question 13.
Read the function of parts of a plant given below.
(a) Fixes plant to the soil
(b) Prepares starch
(c) Takes part in reproduction
(d) Supports branches and bears flowers
In the diagram given in Fig. 7.1, write the names of the parts whose functions you have just read at the appropriate space.
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-1
Solution:
(a) Root
(b) Leaf
(c) Flower
(d) Stem
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-2

Question 14.
Draw the veins of leaves given in Fig 7.2 below and write the type of venation.
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-3
Solution:
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-4

Question 15.
Observe Fig. 7.3 and attempt the questions that follow it.
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-5
(a) Label the parts 1, 2, 3 and 4 in the diagram.
(b) What type of venation does the leaf has?
(c) What type of venation is seen in grass leaves? .
(b) The leaf has reticulate venation. In reticulate venation, veins form a network.
(c) In grass leaves, parallel venation is seen. In parallel venation, the veins run parallel to one another.
Solution:
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-6
(b) The leaf has reticulate venation. In reticulate venation, veins form a network.
(c) In grass leaves, parallel venation is seen. In parallel venation, the veins run parallel to one another.

Question 16.
0bserve the picture of an activity given as Fig. 7.4 carried out with leaves of plants and polythene bag.
Now answer the following.
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-7
(a) Which process is demonstrated in the activity?
(b) When will this activity show better results on a bright sunny day or a cloudy day?
(c) What will you observe in the polythene bag after a few hours of setting up the activity?
(d) Mention any one precaution you must
Solution:
(a) The process of transpiration is being demonstrate a in the given activity. The loss of water in the vapour form from the exposed parts of a plant (mainly leaves) is called transpiration.
(b) The activity will show better results on a bright sunny day because the rate of transpiration increases in the presence of strong sunlight.
(c) After a few hours, small drops of water will be seen inside the polythene cover.
(d) (i) The set-up must be airtight.
(ii) Polythene bag must be dry.
(iii) The twig must be fresh with 10-12 leaves.

Question 17.
Identify the wrong statements and correct them.
(a) Anther is a part of the pistil.
(b) The visible parts of a bud are the petals.
(c) Lateral roots are present in a tap root.
(d) Leaves perform the function of transpira-tion only.
Solution:
(a) Wrong – Anther is a part of the stamen.
(b) Wrong – The visible parts of a bud are the sepals.
(c) Correct
(d) Wrong – Leaves perform the various functions other than transpiration, such as photosynthesis, gaseous exchange through stomata etc.

Question 18.
Solve the crossword given in Fig. 7.5 as per the clues given below it.
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-8
1. The term that describes upward movement of water in a stem.
3. The part of leaf which is attached to the stem.
5. This part is attached to the tip of filament.
Down
1. Plants that are weak and spread on the ground.
2. Ovules are present in this part of flower.
4. Is the broad part of leaf.
Solution:
NCERT Exemplar Class 6 Science Chapter 7 Getting to Know Plants img-9
Across
1. CONDUCTION
3. PETIOLE
5. ANTHER
Down
1. CREEPERS
2. OVARY
4. LAMINA.
Question 19.
Fill in the blanks with the terms that are listed below.
anther, male, ovary, ovule, petals, pistil, stamen, filament.
Sepals, (a)____ . stamens and (b)____ are the parts of a flower. Stamen is made up of (c)____ and (d)____ and it represents the (e)____part of the flower. The female part of the flower is called the (f)_____. The basal, swollen part of the pistil is called the (g)____ which contains the (h)_____.
(a) petals
(b) pistil,
(c) anther,
(d) filament,
(e) male,
(f) pistil,
(g) ovary,
(h) ovules.

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NCERT Exemplar Class 6 Science Chapter 2 Components of Food

NCERT Exemplar Class 6 Science Chapter 2 Components of Food are part of NCERT Exemplar Class 6 Science. Here we have given NCERT Exemplar Class 6 Science Solutions Chapter 2 Components of Food.

NCERT Exemplar Class 6 Science Chapter 2 Components of Food

Multiple Choice Questions.

Question 1.
Which one of the following food item does not provide dietary fibre?
(a) Wholegrains
(b) Whole pulses
(c) Fruits and vegetables
(d) Milk
Solution:
(d): Dietary fibre is formed of cellulose and is obtained mainly from plant products. Whole grains, whole pulses, fruits and vegetables are rich sources of dietary fibre. Animal products (e.g. milk) do not contain dietary fibre.

Question 2.
Which of the following sources of protein is different from others?
(a) Peas
(b) Gram
(c) Soyabeans
(d) Cottage cheese (paneer)
Solution:
(d) : Peas, gram and soyabeans are the sources of plant proteins whereas cottage cheese (paneer) is the source of animal protein.

Question 3.
Which of the following nutrients is not present in milk?
(a) Protein
(b) Vitamin C
(c) Calcium
(d) Vitamin D
Solution:
(b) : Protein, calcium and vitamin D are present in considerable amounts in milk whereas vitamin C is present in negligible amount in milk.

Question 4.
Read the food items given below.
(i) Wheat
(ii) Ghee
(iii) Iodised salt
(iv) Spinach (palak)
Which of the above food items are “energy giving foods”?
(a) (i) and (iv)
(b) (ii) and (iv)
(c) (i) and (ii)
(d) (iii) and (iv)
Solution:
(c): Fats and carbohydrates are energy giving foods. Ghee is rich in fats and wheat is rich in carbohydrates. So, these are energy giving foods. Iodised salt and spinach are protective foods because iodised salt contain minerals and spinach is rich in both minerals and vitamins.

Question 5.
Read the following statements about diseases.
(i) They are caused by germs.
(ii) They are caused due to lack of nutrients in our diet.
(iii) They can be passed on to another person through contact.
(iv) They can be prevented by taking a balanced diet.
Which pair of statements best describe a deficiency disease?
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (ii) and (iv)
(d) (i) and (iii)
Solution:
(c): Deficiency diseases are the diseases which are caused by deficiency of nutrients in the diet. These are non infectious and do not spread from one to another person.

Question 6.
Given below are the steps to test the presence of proteins in a food item.
(i) Take a small quantity of the food item in a test tube, add 10 drops of water to it and shake it.
(ii) Make a paste or powder of food to be tested.
(iii) Add 10 drops of caustic soda solution to the test tube and shake well.
(iv) Add 2 drops of copper sulphate solution to it.
Which of the following is the correct sequence of the steps?
(a) i, ii, iv, iii
(b) ii, i, iv, iii
(c) ii, i, iii, iv
(d) iv, ii, i, iii
Solution:
(b): To test the presence of proteins in a food item, first make a paste or powder of food to be tested (ii), then take small quantity of the food item in a test tube, add 10 drops of water to it and shake it (i). After that add 2 drops of copper sulphate solution to it (iv), and finally add 10 drops of caustic soda solution to the test tube and shake well (iii). Let the test tube stand for a few minutes and observe the colour of the solution in the test tube. Appearance of violet colour indicates the presence of proteins in the given food item.

Short Answer Type Questions

Question 7.
Unscramble the following words related to components of food and write them in thespace provided.
(a) reinpot___________
(b) menliars __________
(c) tivanmi ___________
(d) bocatradhyer _______
(e) nitesturn__________
(f) tfa_______________
Solution:
(a) Protein
(b) Minerals
(c) Vitamin
(d) Carbohydrate
(e) Nutrients
(f) Fat

Question 8.
Which of the following food items does not provide any nutrient
[Milk, Water, Orange juice, Tomato soup]
Solution:
Water does not provide us any nutrient yet it is essential for life.

Short Answer Type Questions

Question 9.
Fill in the blanks from the list of words given below.
(carbohydrate, fat, protein, starch, sugar, vitamin A, vitamin C, roughage, balanced diet, obesity, goitre)
(a) Egg yolk is rich in_____and egg albumin is rich in___.
(b) Deficiency diseases can be prevented by taking a____.
(c) Eating too much of fat rich foods may lead to a condition called____.
(d) The component of food that does not provide any nutrient to our body and yet is essential in our food is_____.
(e) The vitamin that gets easily destroyed by heating during cooking is ____.
Solution:
(a) fat, protein
(b) balanced diet
(c) obesity
(d) roughage
(e) vitamin C

Question 10.
Read the items of food listed below. Classify them into carbohydrate rich, protein rich and fat rich foods and fill them in the given table. Moong dal, fish, mustard oil, sweet potato, milk, rice, egg, beans, butter, butter milk (chhachh), cottage cheese (paneer), peas, maize, white bread.

Carbohydrate Rich Food Item (A) Protein Rich Food Item (B) Fat Rich Food Item (C)
…………………… ……………. ……………..
…………………… ……………. ……………..
…………………… ……………. ………………
…………………… ……………. ………………
…………………… ……………. ……………..
…………………… ……………. ……………..
…………………… ……………. ……………..
…………………… ……………. ……………..

Solution:

Carbohydrate Rich Food Item (A) Protein Rich Food Item (B) Fat Rich Food Item (C)
Sweet potato Moong dal Mustard oil
Rice Fish Cottage cheese
Maize Milk Milk
White bread Egg Egg
Beans Butter
Butter milk Fish
Cottage cheese
Pea

Question 11.
Tasty food is not always nutritious and nutritious food may not always be tasty to eat. Comment with examples.
Solution:
Tasty food is not always nutritious, e.g., burger, samosa, chowmin, potato chips etc. are very tasty but not nutritious. These foods contain refined flour (maida), spices and lot of oil which is not good for health. On the other hand, nutritious food may not always be tasty to eat, e.g., boiled vegetables, pulses etc. are not always tasty but are very good for health. These foods contain important nutrients (proteins, vitamins, minerals etc.) which help to make us strong and healthy.

Question 12.
While using iodine in the laboratory, some drops of iodine fell on Paheli’s socks and some fell on her teacher saree. The drops of iodine on the saree turned blue black while their colour did not change on the socks. What can be the possible reason?
Solution:
The saree of Paheli’s teacher might have been starched. As starch turns blue black with iodine solution, so the saree also turned blue- black. Paheli’s socks did not have starch thus did not show any colour change.

Question 13.
Paheli and Boojho peeled some potatoes and cut them into small pieces. They washed and boiled them in water. They threw away the excess water and fried them in oil adding salt and spices. Although the potato dish tasted very good, its nutrient value was less. Suggest a method of cooking potatoes that will not lower the nutrients in them.
Solution:
Potatoes are nutritious vegetables that provide carbohydrates, vitamins (especially vitamin C), minerals and dietary fibre. Consuming potatoes along with their skin (peel) provides extra dietary fibre and nutrients. A method of cooking potatoes that will not lower their nutrient value is :
Wash the potatoes and cut them into thin slices. Cook the potatoes in little amount of oil and some water by adding salt and spices. Cover the cooking pot while cooking. This method helps to conserve the nutrients of potatoes.

Question 14.
Paheli avoids eating vegetables but likes to eat biscuits, noodles and white bread. She frequently complains of stomach ache and constipation. What are the food items that she should include in her diet to get rid of the problem? Give reason for your answer.
Solution:
Paheli must include whole grains, whole pulses, fresh fruits and vegetables in her diet to get rid of her problem. These food items contain roughage (dietary fibre) which is lacking in Paheli’s diet. Biscuits, noodles and white bread are made up of refined flour (maida) which does not contain any roughage. Roughage prevents constipation, since it allows the waste matter to move more easily down the lower intestine helping us to get rid of undigested waste.

Question 15.
(a) List all those components of food that provide nutrients.
(b) Mention two components of food that do not provide nutrients.
Solution:
(a) Components of food that provide nutrients are carbohydrates, fats, proteins, vitamins and minerals.
(b) Components of food that do not provide nutrients are roughage and water.

Question 16.
‘Minerals and vitamins are needed in very small quantities by our body as compared to other components, yet, they are an important part of a balanced diet’. Explain the statement.
Solution:
Minerals and vitamins are needed in very small quantities but are essential for the normal functioning of our body. It is because
(i) They are protective foods and help in protecting our body against diseases.
(ii) They help in normal growth of our body.
(iii) They help in maintaining good health.

Question 17.
‘Water does not provide nutrients, yet it is an important component of food’. Explain.
Solution:
Water is a vital component of our food because
(i) Water helps our body to absorb nutrients from food.
(ii) Water helps in removing wastes in the form of urine and sweat.
(iii) Water transports nutrients throughout the body.
(iv) Water helps to maintain temperature of our body.

Long Answer Type Questions

Question 18.
Boojho was having difficulty in seeing things in dim light. The doctor tested his eyesight and prescribed a particular vitamin supplement. He also advised him to include a few food items in his diet.
(a) Which deficiency disease is he suffering from?
(b) Which food component may be lacking in his diet?
(c) Suggest some food items that he should include in his diet, (any four)
Solution:
(a) He is suffering from night blindness, which is the inability to see in dim light.
(b) Vitamin A may be lacking in his diet because night blindness is caused by the deficiency of vitamin A.
(c) Carrot, papaya, mango, milk, green leafy, vegetables, fish oil, etc. are food items rich in vitamin A. Therefore, Boojho should include these items in his diet.

Question 19.
Solve the cross-word puzzle given as fig. 2.1 from the dues given below.
NCERT Exemplar Class 6 Science Chapter 2 Components of Food - 1
Across
1. Lack of nutrients in our diet over a long period causes these diseases (10)
2. Rice and potato are rich in this type of carbohydrate (6)
3. Deficiency disease in bones making it become soft and bent (7)
4. The diet that provides all the nutrients that our body needs, in right quantities, along with adequate amount of roughage and water (8, 4)
5. Deficiency disease with bleeding gums (6)
6. Disease caused due to deficiency of iodine (6)
Down
7. Starch and sugar in our food are rich in this type of energy giving nutrient (13)
8. The term given to the useful components of food (9)
9. The disease caused by deficiency of iron in diet (7)
10. Green leafy vegetables, liver and apples are rich in this mineral (4)
11. Deficiency disease caused due to lack of vitamin B in the diet (8)
Solution:
NCERT Exemplar Class 6 Science Chapter 2 Components of Food img-1
Question 20.
Observe the items given in Fig. 2.2 carefully and answer the questions that follow.
NCERT Exemplar Class 6 Science Chapter 2 Components of Food img-2
(a) Food item rich in carbohydrates is___(i)______
(b) Egg is a rich source of protein, the mineral____(ii)__and vitamin __(iii)______
(c) ____(iv)___is a rich source of fat.
(d) Milk provides __(v)____ vitamin D and ___(vi)____(mineral).
(e) ___(vii)____(fruit) is a rich source of vitamin A.
(f) Spinach is a good source of the mineral__(viii)____
(g) Both eggs and ___(xi)____are rich in___(x)______
Solution:
(a) (i) chapati
(b) (ii) phosphorus (iii) D
(c) (iv) Butter
(d) (v) protein (vi) calcium
(e) (vii) Papaya
(f) (viii) iron
(g) (ix) peas (x) proteins

Question 21.
SNAKES AND LADDERS
Make a board-game just like ‘snakes and ladders’ with 10 x 10 grid boxes.
The mouth of the snake will represent the faulty food habit or faulty method of cooking. Its tail will represent the deficiency disease caused or loss of any nutrient in food.
Similarly, the box at the base of a ladder will represent healthy food habit or healthy method of cooking. Its upper end will represent the beneficial effect of that habit. An example is given as Fig. 2.3. Complete the board and play with your friends.
NCERT Exemplar Class 6 Science Chapter 2 Components of Food img-3
Solution:
The terms to be put at the mouths and tails of snakes at different grid numbers are as follows

Mouth of snake (Faulty food habits or Cooking method) Tail of snake (Deficiency disease or loss of nutrient)
17. Eating food deficient in protein 7. Kwashiorkor
54. Lack of exposure to sunlight 34. Rickets
62. Absence of iron in diet 19. Anaemia
64. Less intake of fibre rich food 60. Constipation
83. Excessive cooking (or heating) of food 73.Vitamin C
95. Not taking green leafy vegetables and yellow fruits 75. Vitamin A deficiency
98. Not using iodised salt for cooking 79. Goitre

The terms to be put at the base and upper end of the ladders at different grid number are as follows:

Base of ladder (Healthy food habit or cooking method) Upper end of ladder (Beneficial effect of that habit)
4. Intake of milk, cheese and green vegetables 14. Upper end of ladder(Beneficial effect of that habit
9. Regular consumption of spinach, liver and apple 14. Healthy bones and teeth
19. Eating carrots, papaya  and banana 38. Sufficlient haemoglobin
21. Eating whole grains, pulses and fruits 42. Proper bowel movement
51. Drinking plenty of water 67. Body remains hydrated
71. Intake of citrus fruits 91. Healthy gums
80. Avoiding junk foods 100. Staying fit and healthy

We hope the NCERT Exemplar Class 6 Science Chapter 2 Components of Food will help you. If you have any query regarding NCERT Exemplar Class 6 Science Solutions Chapter 2 Components of Food, drop a comment below and we will get back to you at the earliest.