Air – Chapter 4 Geography Class 7 NCERT Solutions

Answer the following questions.

 

1. What is the meaning of atmosphere?

Ans. Atmosphere is the huge blanket of air that is surrounding the planet earth. All living beings on earth depends on the atmosphere for their survival.

 

2. Which are the two gases that makes the bulk of the atmosphere?

Ans. Those two gases are Nitrogen and Oxygen.

 

3. Which gas is responsible for creating greenhouse effect in the atmosphere?

Ans. Carbon Dioxide CO2 is the gas that is responsible. It creates green house effect by trapping the heat of the earth from going out in space.

 

4. What is weather?

Ans. Weather is the hour-to-hour, day to day condition of the atmosphere. It can change dramatically from day to day.

 

5. Name three types of rainfall?

Ans. On the basis of mechanism, there are three types of rainfall: the convectional rainfall, the orographic rainfall and the cyclonic rainfall.

 

6. What is air pressure?

Ans. It is the pressure exerted by the weight of the air on the earth’s surface.

 

Give reasons.

 

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

Ans. Humidity is associated with moisture. Moisture is created when water evaporates from land and different water bodies. Therefore moisture in the air at any time, is known as humidity. When there is a lot of water vapor in the air, the day is called as a humid day. Since there is already a lot of water vapor in the air therefore it takes longer to dry clothes as the water does not evaporates easily.

 

2. Amount of insulation decreases from equator towards poles?

Ans. The meaning for insulation is the incoming solar energy from the sun on the surface of the earth. At equator, the amount of solar energy that comes is much higher than compare to the North and South poles. That is why as we move away from the equator and head toward pole area the temperature naturally decreases resulting in low insulation. This is also the reason why the North and South pole is covered with snow.

Leave a Reply

Your email address will not be published.