Which statement is NOT a mode of heat transfer?

Which statement is NOT a mode of heat transfer?

• A. Radiation
• B. Conduction
• C. Convection
• D. Evaporation

Answer: (D)

Heat moves through three recognized mechanisms: conduction, where energy transfers through direct contact within a material; convection, where the movement of a fluid carries energy; and radiation, which transfers energy via electromagnetic waves across space. Evaporation is a phase-change process that requires latent heat to turn liquid into vapor. While heat input drives evaporation, it isn’t a separate mechanism of heat transfer, so it isn’t considered a mode on its own. Hence evaporation is not a mode of heat transfer.

Heat moves through three recognized mechanisms: conduction, where energy transfers through direct contact within a material; convection, where the movement of a fluid carries energy; and radiation, which transfers energy via electromagnetic waves across space. Evaporation is a phase-change process that requires latent heat to turn liquid into vapor. While heat input drives evaporation, it isn’t a separate mechanism of heat transfer, so it isn’t considered a mode on its own. Hence evaporation is not a mode of heat transfer.