NCERT Exemplar Solution Class 6 Science Chapter 15 Air Around Us Full Explanation. NCERT Exemplar Class 6 Science – Chapter 15 Air Around Us. NCERT Exemplar Class 6 Science Air Around Us Solution by Expert.
NCERT Exemplar Class 6 Science Air Around Us Solution
- Multiple Choice Questions
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 .
Answer:- d) Air is present everywhere but not in soil.
Air is also present in soil particles. These air is further helps in growth of plants.
2) Wind does not help in the movement of which of the following?
a) Firki
b) Weather cock
c) Ceiling fan
d) Sailing yacht
Answer:- c) Ceiling fan
Ceiling fans are connected to the electric circuits. And these are moved by the switch on the current.
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.
Answer:- d) It has no role in water cycle.
Air also plays an important role in water cycle.
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 us used for cooking.
d) Oxygen keeps them warm at low temperature.
Answer:- b) There is Deficiency of oxygen on mountains at high altitude.
As we go on higher in the sky oxygen levels decreases.
5) Boojho took an empty plastic bottle, turned it upside down and dipped it’s open mouth into a bucket filled with water. He then titled 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 come 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
Answer:- a) I) and II)
When the open bottle will be dipped into the bucket filled with water then some water will go inside the bottle and the air which was present in the bottle comes out in the form of bubbles.
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
Answer:- a) Nitrogen
Nitrogen is present about 70 % of the atmosphere air .
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
Answer:- c) Dust and smoke
Dust and Smoke is very harmful for living being if inhaled in more quantity it may cause damage to our lungs.
8) Usha took a lump of dry soil of 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
Answer:- c) Air.
Air is dissolved in soil, when the water is added to the soil it becomes moist and dissolved air evolved out in the atmosphere.
- Very Short Answer Questions
9) State whether the following statements are true or false. If false, correct them.
a) Plants consume oxygen for respiration.
Answer:-True.
b) Plants produce oxygen during the process of making their own food.
Answer:-True.
c) Air helps in the movements of sailing yachts and glider but plays no role in the flight of birds and aeroplanes.
Answer:- False.
Air also plays an important role in the flight of birds and aeroplanes.
d) Air does not occupy any space.
Answer:- False.
Air occupies space. But is not visible.
10) In a number of musical instruments, air plays an important role. Can you name some such instruments?
Answer:- some of the musical instruments are played with the help of air, these instruments are Harmonium , flute, and shahnai. For playing these instruments air is very important.
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.
Answer:-
Column I – Column II
a) DILLMWIN → Windmill
b) YNOGXE → Oxygen
c) MESKO → Smoke
d) TUDS → Dust
12) Make sentences using the given set of words.
a) 99% , oxygen, nitrogen, air, together
Answer:-
Nitrogen and oxygen forms the 99% of the air together.
b) Respiration, dissolved, animals, air, aquatic
Answer:-
Aquatic Animals uses dissolved air or oxygen for the respiration.
c) Air, wind, motion, called
Answer:- Motion of Air is called Wind.
- Short Answer Questions
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.
Answer:- The wind makes the windmill rotate.
b) Air is a _________ of some gases.
Answer:- Air is a mixture of some gases.
c) A weather cock shows the _________ in which the air is moving at that place.
Answer:- A weather cock shows the direction in which the air is moving at that place.
d) Mountaineers carry oxygen __________ with them, while climbing high mountains.
Answer:- Mountaineers carry oxygen cylinders with them, while climbing high mountains.
14) Observe the picture given in fig. 15.1 carefully and answer the following questions.
a) What is covering the nose and mouth of the police man ?
Answer:- police man is covered the nose with the mask.
b) Why is he putting a cover in his nose?
Answer:- police man is covered the nose with the mask from the protection of air Pollution or dirt, dust.
c) Can you comment on air quality of the place shown in the fig. 15.1?
Answer:-
As we can in picture, the air quality is not good of the place. Air is polluted due the traffic over there. The smoke and gases are emitted by the cars and other vehicles . Also dust and dirt particles present in the air. These clearly shows that the air quality is not good of that place.
15) Garima observed that when she left her tightly capped bottle full of water in the open sunlight, tiny bubbles were formed all around Inside the bottle. Help Garima to know why it so happened?
Answer:- Tightly capped bottle full of water was containing the dissolved air in it. When the Garima kept that bottle open in the sunlight, then the tiny bubbles started escaping out due to the heat of the sun.
16) Match the items of Column I with the items of Column II.
Column I | Column II |
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
|
Answers:-
a) Weather cock→ iv) Direction of air flow
b) Mountaineers → iii) oxygen cylinders
c) fine hair inside the nose → v) prevent dust Particles
d) Smoke → i)Gases and fine dust Particles
e) Wind → ii) sailing yacht
- Long Answer Questions
17) Explain the following observations very briefly
a) A firki does not rotate in a closed area.
Answer:- firki rotates when there is movement of air. The motion of air is known as wind. When there is wind firki rotates, in closed area there is no movement of air thus it does not rotate.
b) The arrow of weather cock points towards a particular direction at a particular moment.
Answer:- the Weather cock shows the direction of the wind. It shows the latest direction of wind, therefore it shows particular direction at particular time.
c) An empty glass in fact is not empty.
Answer:- As we see the glass is empty. Even dough the glass is not empty.There may be not any liquid in the glass but there is air filled in the glass.
d) Breathing through mouth may harm you.
Answer:- Breathing process is function of nose. Nose has very small hairs, which prevents the dust and dirt particles going inside the body. But mouth cannot prevent that dust and dirt particles going inside the body and thus it can be harmful for our heal
18) Write just a few sentences for an imaginary situation if any of the following gases disappear from the atmosphere
a) Oxygen
Answer:- If there will be no oxygen, No life will be there on the earth. Oxygen is very much important for the living being to live.
b) Nitrogen
Answer:- Nitrogen will disappear from the atmosphere, things will be burn very fast.
c) Carbon dioxide
Answer:- Carbon dioxide is important for plants life. Plant could not make there own food without carbon dioxide. And if there will not be plants there will not be life on earth.
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?
Answer:- when the water started boiling, the air which was dissolved in the water started evolving. Thus the tiny bubbles appeared there.
b) Do you think tiny bubbles will appear on heating the water taken out from the bottle? Justify your answer.
Answer:- No. Tiny bubbles will not appear there because the water from the bottle does not contain dissolved air. Therefore bubbles will not appear on heating.
20) On a Saturday 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?
Answer:- The roadside plants may got dull due to the dust and dirt present on the road blow with air and stick on the leaves and flowers. Roadside plants do not get water daily as we water the plants in the garden. Therefore the garden plants remains fresh and beautiful.