Which mode of heat transfer moves heat directly from one object to another?

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

Answer: (C)

Heat moving directly from one object to another happens through conduction. This occurs when objects are in contact or when heat travels through a solid material from the hotter region to the cooler region by transferring energy molecule to molecule. The energy moves without any overall movement of the surrounding medium. A common example is a metal spoon warming up in hot liquid—the heat travels along the spoon from the hot end to the cooler end by conduction. Metals are especially good at this because their particles and free electrons transmit energy quickly.

Convection, by contrast, requires the movement of a fluid, such as air or water, to carry heat as it circulates. Radiation transfers heat via electromagnetic waves and can go through empty space, like sunlight warming the Earth. The term heat of combustion isn’t a transfer mechanism at all—it’s the energy released when a fuel burns.

So, the mode that moves heat directly from one object to another is conduction.