Which term best describes energy transfer via electromagnetic waves emitted by a hot object?

• A. Conduction
• B. Convection
• C. Radiation
• D. Thermal resistance

Answer: (C)

Heat transfer by electromagnetic waves is radiation. This mode sends energy away from a hot object as photons and can travel through empty space, so another object can absorb the energy without touching or needing a surrounding fluid. That’s why you can feel warmth from a fire or the Sun even though there’s no direct contact or air in between. Conduction requires direct contact and transfer between nearby particles, while convection relies on the bulk movement of a fluid carrying heat. The warmer the object and the surface characteristics, the more energy it radiates, so hotter objects glow and emit more infrared energy.