Chapter-Air (Class 7th)

Which gas creates a greenhouse effect?

• Carbon dioxide

• Nitrogen

• Oxygen

• Hydrogen

Ionosphere is part of which later of atmosphere?

• Mesosphere

• Stratosphere

• Thermosphere

• Exosphere

Which gas is present in highest amount in atmosphere?

• Oxygen

• Nitrogen

• Hydrogen

• Carbon dioxide

In which layer of atmosphere, does airplanes present?

• Stratosphere

• Thermosphere

• Exosphere

• Mesosphere

Which layer is upper most layer?

• Mesosphere

• Troposphere

• Exosphere

• Thermosphere

Degree of hotness and coldness in air is called

• Humidity

• Pressure

• Insolation

• Temperature

Which winds change their directions in different seasons?

• Local winds

• Permanent winds

• Seasonal winds

• None of the above

What is the result when the air is heated?

• Heavier

• Lighter

• Warmer

• Cooler

How much percentage of oxygen is present in atmosphere?

How ozone layer is important to us?

• Protects us from weather changes

• Protects us from harmful rays

• Protects us from rain

• None of the above