Which statement concerning radiation is correct?
A) It refers to heat emission from a warm object in the form of electromagnetic waves.
B) It is only a source of heat loss for the body (i.e., the body can lose but not gain heat by radiation).
C) It refers to the transfer of heat by direct contact between a warmer and cooler object.
D) It involves the continued cycling of cool air over the body.

Question

Quizplus · Accepted Answer

Radiation refers to heat emission from a warm object in the form of electromagnetic waves, which can travel through a vacuum or transparent medium. This is different from conduction and convection, which require contact or movement of matter, respectively.

Answer: B
 Radiation can both transfer heat to and from the body, depending on the temperature and surroundings. For example, the body can absorb radiant heat from the sun or a heating source, or emit radiant heat to cooler objects or the air.

Answer: C and D are incorrect.
 Conduction refers to the transfer of heat by direct contact between objects, while convection involves the movement of fluid (such as air or water) to transfer heat. Neither of these processes is referred to as radiation. Cycling of cool air over the body is not a process of radiation, but rather an example of convective cooling (as in a fan or wind).

Which Statement Concerning Radiation Is Correct