Which term correctly matches heat transfer by direct contact?

Which term correctly matches heat transfer by direct contact?

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

Answer: (A)

Heat transfer by direct contact is conduction. It happens when energy moves from a hotter object to a cooler one through touch or through a solid material, driven by particle interactions. In metals, free electrons help shuttle energy quickly from the hot side to the cool side, while in other solids it’s mainly vibrations of the atoms that pass the energy along. A familiar example is touching a hot mug; heat flows into your hand because the mug and your skin are in direct contact. The other two options don’t fit the mechanism: convection requires movement of a fluid or gas carrying heat, and radiation transfers energy via waves without any contact. Absorption isn’t a heat-transfer mechanism by itself, but rather the process of a material taking in energy from another source.

Heat transfer by direct contact is conduction. It happens when energy moves from a hotter object to a cooler one through touch or through a solid material, driven by particle interactions. In metals, free electrons help shuttle energy quickly from the hot side to the cool side, while in other solids it’s mainly vibrations of the atoms that pass the energy along. A familiar example is touching a hot mug; heat flows into your hand because the mug and your skin are in direct contact. The other two options don’t fit the mechanism: convection requires movement of a fluid or gas carrying heat, and radiation transfers energy via waves without any contact. Absorption isn’t a heat-transfer mechanism by itself, but rather the process of a material taking in energy from another source.