Warm Air and Cool Air

Q. $Statement1:$ Hot air is lighter than cold air.
$Statement2:$ Cold air is lighter than hot air.

1. Both statements are false.
2. Both statements are true.
3. Statement 2 is true and statement 1 is false.
4. Statement 1 is true and statement 2 is false.

Q.

What happens to air when it is heated?

1. Contracts

2. Expands

3. Moves down

4. Movement ceases

Q.

When hot air rises up, the number of air particles in the region:

1. Becomes zero

2. Increases

3. Decreases

4. Remains the same

Q.

When hot air rises up from a region, the region becomes:

1. High pressure region.

2. Low pressure region.

3. Independent of temperature.

4. Independent of pressure.

Q.

Hot air is less dense than cold air.

1. False

2. True

Q.

Molecules at a higher temperature have more energy.

1. True

2. False

Q.

Warm air is ______ than cold air.

1. lighter
2. denser
3. heavier
4. either heavier or lighter

Q.

If we take same amount of hot and cold air, in a given fixed volume of a container, then which of the following statements is correct?

1. Hot air exerts more pressure on the walls of the container.

2. Cold air exerts more pressure on the walls of the container.

3. Both hot and cold air exert same pressure on the walls of the container.

4. Pressure of hot and cold air cannot be compared.

Q. We have learned about kinetic energy and its relation to the heat. State true or false:

The kinetic energy of the air particle increases if we increase its speed.

1. False
2. True

Q. The volume of the air _______, when we heat the air.

1. increases
2. decreases
3. doesn't change
4. becomes zero