Air Conditioning Repair Certification (ETI) Practice Exam

The movement of heat through a solid object is described by the process of conduction. Conduction occurs when heat is transferred from one molecule to another within a solid material due to direct contact. This process relies on the vibration and movement of particles within the solid, allowing thermal energy to be passed from the hotter regions to the cooler regions of the object until thermal equilibrium is reached.

In contrast, convection involves the transfer of heat through fluids (liquids or gases) where warmer regions of the fluid rise while cooler regions sink, creating a circulation pattern. Advection is a term often used in meteorology and refers to the horizontal movement of air or water that carries heat and moisture, and radiation is the transfer of heat through electromagnetic waves, such as infrared radiation, without necessarily involving a medium. Thus, conduction is distinct and specific to solids, making it the correct choice for describing heat movement in this context.