Question 1:

Which of the following heat transfer mechanisms does not require a medium to transfer heat?

Explanation: The correct answer is C) Radiation. Radiation is the transfer of heat through electromagnetic waves and does not require a medium to propagate. It can occur in a vacuum or through transparent media.

Question 2:

Which heat transfer mechanism is primarily responsible for the circulation of air in a room when a heater is turned on?

Explanation: The correct answer is B) Convection. Convection is the transfer of heat through the movement of fluids (liquids or gases). In this case, the heated air near the heater rises, creating a convection current that circulates the air in the room.

Question 3:

Which of the following objects will heat up the fastest when exposed to sunlight?

Explanation: The correct answer is A) A black metal plate. Black surfaces absorb more radiation than white or transparent surfaces. Therefore, a black metal plate will absorb more sunlight and heat up faster compared to the other objects.

Question 4:

Which of the following heat transfer mechanisms is responsible for transferring heat through direct contact between objects?

Explanation: The correct answer is A) Conduction. Conduction is the transfer of heat through direct contact between objects or within a solid object. It occurs when heat flows from a region of higher temperature to a region of lower temperature.

Question 5:

Which heat transfer mechanism is primarily responsible for the heat transfer in a vacuum flask?

Explanation: The correct answer is C) Radiation. In a vacuum flask, heat transfer primarily occurs through radiation. The flask is designed with a reflective surface that minimizes radiation losses, keeping the contents hot or cold for an extended period.