Properties of Air

Q.

What does air contain?

Q.

Air exerts pressure equally in all the directions.

1. False

2. True

Q. _______ protects us from the harmful UV rays of the sun.

1. Oxygen
2. Carbon dioxide
3. Ozone
4. Nitrogen

Q.

Nitrogen constitutes nearly ____ % of the atmosphere.

1. 21
2. 42
3. 57
4. 78

Q. The air that we breathe out is:

1. Hot and contains water vapour
2. Hot and does not contain water vapour
3. Cold and contains water vapour
4. Cold and does not contain water vapour

Q.

Ozone is the blanket of air that surrounds the Earth.

1. True

2. False

Q.

Which of these is not a constituent of the atmosphere?

1. Oxygen

2. Aluminium

3. Nitrogen

4. Carbon dioxide

Q.

Which of these is not a constituent of the atmosphere?

1. Oxygen

2. Aluminium

3. Nitrogen

4. Carbon dioxide

Q.

Which of the following is not a property of air?

1. Air has mass.
2. Air occupies space.
3. Air is colourless.
4. Air has taste and odour.

Q. The force of surface tension acts tangentially to the surface whereas the force due to air pressure acts perpendicularly on the surface. How is then the force due to excess pressure inside a bubble balanced by the force due to the surface tension?

Q.

Which among the following statements is incorrect?

1. Air is required for burning

2. Air exerts pressure on the surroundings

3. It is easy to crush a closed plastic bottle

4. Air contains gases like nitrogen, oxygen and carbon dioxide

Q.

Give the percentage of the following gases in air;

• Oxygen
• Nitrogen

Q. Which gas makes up around 21% of our atmosphere?

1. Nitrogen
2. Hydrogen
3. Carbon dioxide
4. Oxygen

Q.

Nitrogen constitutes nearly ____ % of the atmosphere.

1. 21
2. 42
3. 57
4. 78

Q.

A small amount of water is boiled in a metal can with thin walls of iron. When steam comes out freely, the mouth of the can is screwed with a cap and cold water is poured over it. It is observed that the can gets crushed. The experiment proves that air exerts pressure:

1. sideways

2. downward

3. upward

4. none of the above

Q.

Nitrogen constitutes nearly ____ % of the atmosphere.

1. 21
2. 57
3. 42
4. 78

Q. Our atmosphere has_____ nitrogen gas.

1. 70%
2. 78%
3. 72%
4. 75%

Q. Assertion: At great heights from the surface of earth, ionisation of air is less
Reason: Ionisation of air depends on the distance of respective layer from the Sun

1. Assertion and reason are true and reason is the correct explanation of assertion
2. Assertion is true but reason is false
3. Assertion is false but Reason is true
4. Assertion and reason are true but reason is not correct explanation of assertion