Which mechanism describes heat transfer in the form of invisible electromagnetic waves?

Which mechanism describes heat transfer in the form of invisible electromagnetic waves?

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

Answer: (A)

Radiation describes heat transfer through electromagnetic waves. This form of heat can travel through empty space and doesn’t require a material medium, which is why you can feel the Sun’s warmth on Earth even though space has no air. In a fire, the surrounding heat you feel at a distance comes from infrared radiation emitted by the hot flames and hot surfaces.

Conduction, by contrast, needs direct contact and works through molecular interactions within or between solids. Convection relies on the movement of fluids (air or liquid) carrying heat with circulating currents. Combustion is the chemical reaction that releases heat (and light); it’s the source of heat, not a method of transferring it.

So the mechanism described by heat transfer via invisible electromagnetic waves is radiation.