Solution of Chapter 4. Air (Our Environment Book)

Exercise

1

What is atmosphere?
1

Which two gases make the bulk of atmosphere?
1

Which gas creates greenhouse effect in atmosphere?
1

What is weather?
1

Name three types of rainfall?
1

What is air pressure?
2

Tick the correct Answer.

Which of the following gases protects us from harmful sun rays?


(a) Carbon dioxide.


(b) Nitrogen.


(c) Ozone.
2

Tick the correct Answer.

The most important layer of the atmosphere is.


(a) Troposphere.


(b)Thermosphere.


(c) Mesosphere
2

Tick the correct Answer.

Which of the following layers of atmosphere is free from clouds?


(a) Troposphere.


(b) Stratosphere.


(c) Mesosphere
2

Tick the correct Answer.

As we go up the layers of the atmosphere, the pressure


(a) Increases.


(b) Decreases.


(c) Remain same.
2

Tick the correct Answer.

When precipitation comes down to the earth in the liquid form, it is called


(a) cloud


(b) Rain


(c) Snow
3

Match the following:


(i) Trade Winds



(a) Incoming solar energy



(ii) Loo



(b) Seasonal wind



(iii) Monsoon



(c) Horizontal movement of Air



(iv) Wind



(d) Layer of ozone gas




(e) Permanent wind




(f) Local wind
4

Give reasons

Wet clothes take longer time to dry on a humid day?
4

Give reasons

Amount of insolation decreases from equator towards poles?
5

For fun

Solve this crossword puzzle with the help of given clues:



Across


6. An Indian tree having extraordinary quality of providing oxygen round the clock


8. Gas present in atmosphere occupying only 0.03% by volume


11. Outermost layer of atmosphere


12. Mixture of many gases


14. Life giving gas


15. Air in motion


16. An Indian tree valued highly for medicinal properties


18. Gas protecting us from harmful sunrays


19. Low pressure area


Down


1. Amount of water vapor in air


2. Condensation of water vapors around


dust particles in atmosphere


3. Example of local wind blowing in summer in northern India


4. Short term changes in atmosphere


5. Precipitation in liquid form


7. Blanket of air around the earth


9. Instrument to measure pressure


10. Incoming solar radiation


13. Reduces visibility in winters


17. It is ....... time when sun is overhead
5

For fun

Make a weather calendar for one weak. Use pictures or symbols to show different types of weather. You can use more than one symbol in a day, If the weather changes. For example, the sun comes out when rain stops. An example is given below: