Ontario Office of the Fire Marshal (OFM) Firefighter I Certification Practice Exam

Thermal energy transfer in convection occurs through the circulation or movement of a fluid, which can be a liquid or a gas. As a fluid is heated, it becomes less dense and tends to rise, while cooler, denser fluid moves in to take its place. This creates a convection current, which effectively transfers heat throughout the fluid.

In contrast, direct contact of materials refers to conduction, where thermal energy is passed through direct contact between solids. The movement of solids isn't applicable to convection since it specifically involves the fluid dynamics of liquids and gases. Electromagnetic waves relate to radiation, where heat is transferred through waves without the need for a medium.

Understanding convection is particularly relevant in firefighting when assessing how heat spreads in different environments, affecting strategies for fire control and safety.