Which heating modality involves transfer of heat through space from one object to another?

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

Answer: (C)

Heat transfer through space from one object to another is due to radiation. This energy travels as electromagnetic waves, so no medium is needed—heat can move through vacuum or air and warm the receiving object directly, like infrared heat from a radiant heater or the sun warming your skin. Conduction, in contrast, requires direct contact and transfers energy through particle interactions in solids. Convection involves the movement of a fluid (air or water) carrying heat as it circulates. Conversion isn’t a heat-transfer process by itself; it’s about changing energy from one form to another.