Convection

Q. Statement 1: Cold air flows from sea to land in the daytime.
Statement 2: Air above the sea gets hot in the daytime and starts flowing towards the land.

1. Both statements are correct
2. Statement 1 is correct but statement 2 is incorrect
3. Both statements are incorrect
4. Statement 2 is correct but statement 1 is incorrect

Q. Transfer of heat in liquids takes place predominantly by:

1. Conduction
2. Convection
3. Radiation
4. Both convection and radiation

Q. The mode of heat transfer in fluids is convection.

1. True
2. False

Q. Which of the following situations explains the meaning of free convection?

1. Air conditioning installations in nuclear reactors
2. Flow of water inside the condenser tubes
3. Cooling of internal combustion engine
4. Drying of clothes in the sun

Q. In which of the following type of convection, a fan or pump is used to increase the rate of heat transfer?

1. Natural convection
2. Forced convection
3. Gravitational convection
4. Adhesive action

Q. Rooms are fitted with ventilators to let the hot air out. What is the phenomenon involved here?

1. Conduction
2. Convection
3. Radiation
4. Insulation

Q. Which of the following statements is true about convection?

1. Convection occurs only in cold liquids.
2. In solids, heat is transferred only by convection.
3. Convection requires a medium for transmission of heat.
4. Heat flows from the cold end to the hot end in a substance.

Q. Convection occurs in solids.

1. False
2. True

Q. Hot air is less dense than cold air.

1. True
2. False

Q. In which of the following processes does heat transfer in the form of movement of particles?

1. Convection
2. Radiation
3. Conduction
4. All of the above.