Density of Hot and Cold Air

Q. Warm air is ______ than cold air.

1. lighter
2. denser
3. heavier
4. humid

Q. Atmospheric pressure _________ with ________ in altitude.

1. increases, increase
2. decreases, decrease
3. decreases, increase
4. remains constant, increase

Q. The warm air is denser than the cold air.

1. True
2. False

Q.

Hot air is less dense than cold air.

1. True

2. False

Q.

Beakers A and B have the same amount of air initially. The beakers are dipped in water at different temperatures. Which of the following statements is correct with respect to the given figure?

1. Water in both the beakers is at the same temperature.
2. Water in beaker A is hotter than that in B.
3. Water in beaker B is hotter than that in A.
4. Temperature of water in beaker A and B cannot be predicted.

Q.

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

1. Decreases

2. Increases

3. Remains the same

4. Becomes zero

Q. A change in air pressure is observed with the change in temperature.

1. False
2. True

Q. Warm air is lighter than cool air.

1. True
2. False

Q. Which of the following is correct when warm air rises up at a place?

1. The surrounding cold air flows away from that place.
2. A low pressure region is created at that place.
3. The surrounding air flows into that place.
4. A high pressure region is created at that place.

Q. What are the utilities of ventilators present near the ceiling of a room?

1. They act as vents for cold air to enter the room.
2. They can be used to store food grains and other things.
3. They act as vents for hot air to pass out of the room.
4. We use them to escape in case of an emergency.