________ is the direct contact of transmission of heat energy from one body to another.

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

Answer: (B)

Direct contact heat transfer is conduction. When two bodies touch, energy moves from the hotter one to the cooler one through collisions and interactions of their atoms and molecules. This is why a hot pan makes a metal rod or a handle warm—the heat travels through the solid by the neighboring particles passing energy along. Conduction is most efficient in solids with good contact, but it also occurs in liquids and gases via molecular interactions. Radiation, in contrast, transfers heat through electromagnetic waves and doesn’t require contact, while convection moves heat with the flow of a fluid or air. Flashover isn’t a heat transfer method; it’s a rapid, dangerous fire behavior.