Air Question Answers: NCERT Class 7 Social Science - Our Environment (Geography)

Exercise 1
Q:
A:

(i) A huge blanket of air by which our earth is covered is known as atmosphere. The atmosphere Contains following layers:
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
- Exosphere
Out of these atmospheric layers, troposphere is the most important layer of the atmosphere which directly support life.

(ii) Nitrogen and oxygen make the bulk of the atmosphere.

(iii) Carbon dioxide gas creates the greenhouse effect in the atmosphere, as it contributes maximus area in the atmosphere.

(iv) Whether is defined as hour to hour and day to day conditions of the atmosphere. It is short term state of the atmosphere. Either is hot or cold wet or dry.

(v) The following types of rainfall are:
- convectional rainfall
- orographic rainfall
- cyclonic rainfall

(vi) Air pressure is defined as the pressure exerted by the weight of air on the earth’s surface.




Q:
A:

(i) This happens because on a humid day, there is more water in air than the sunny day. Because air can soak less water from wet clothes i.e, where rate of evaporation decrease.

(ii) Because sun rays fall vertical on the equator while slanting on the poles.


Q:
A:

1. Humidity: It is defined as the Water vapour present in the air. 

2. Cloud

3. Loo

4. weather

5. Rain

6. Peepal

7. atmosphere: Which is formed of air. 

8. Carbon dioxide

9.Barometer

1o. insolation

11. Exosphere

12. air

13. Fog

14. Oxygen

15. wind

16. Neem

17. Noon

18. ozone: ozone is a layer which protect our earth from sun's harmful UV- radiations.

19. Cyclone: Cyclone is defined as the large air mass which rotates around the strong center which have low atmospheric pressure, in the counterclock-wise direction.