NCIDQ IDFX Practice Exam

Which of the following terms describes the transfer of heat through the movement of a fluid, such as air?

1. Convection

2. Conduction

3. Evaporation

4. Radiation

The correct answer is: Convection

The term that refers to the transfer of heat through the movement of a fluid, such as air, is convection. This process occurs when warmer, less dense areas of a fluid rise while the cooler, denser areas sink, creating a circulation pattern that facilitates the transfer of heat. Convection is commonly observed in various natural phenomena, including weather patterns and the heating of rooms through forced air systems. In contrast, conduction describes the transfer of heat through direct contact between materials, where heat moves from a warmer object to a cooler one without the movement of the materials themselves. Evaporation involves the transition of a substance from a liquid to a gas, which can also remove heat but is not related to fluid movement in the same context. Radiation refers to the transfer of heat through electromagnetic waves and does not require a medium, making it distinct from the fluid movement characteristic of convection. Thus, convection is the accurate term for heat transfer via the movement of air or other fluids.