class 7 geography ch-4 air

Which gas released in the atmosphere creates a greenhouse effect trapping the heat?

• (a) Carbon dioxide

• (b) Nitrogen

Which is the most important layer of the atmosphere?

What is responsible for the excess of CO2?

• global warming

• global cooling

• both a and b

• none of these

What is the result when the air is heated?

• heavier

• lighter

• colder

• warmer

Stratosphere contains a layer of which gas?

• ozone gas

• nitrogen gas

In which layers all weather phenomenon occurs?

• troposphere

• Thermosphere

As we go up in the layers of the atmosphere what is the effect in the pressure?

In which direction the wind blows constantly throughout the year in particular direction?

• Permanent winds

• Seasonal winds

Which one of the following is a local wind?

• Sea breeze

• Trade wind

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

• Ozone

• helium