Which term describes energy transfer through currents caused by differences in temperature in liquids and gases?

Which term describes energy transfer through currents caused by differences in temperature in liquids and gases?

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

Answer: (B)

Convection is energy transfer through currents created in liquids and gases by temperature differences. When part of the fluid is heated, it expands, becomes less dense, and rises. Cooler, denser fluid moves in to take its place and sinks, forming a continuous loop that carries heat with it. This bulk movement explains phenomena like boiling water, warm air rising from a heater, and big-scale atmospheric and ocean currents. Conduction, by contrast, moves energy through direct particle contact without bulk motion; radiation transfers energy via electromagnetic waves and doesn’t rely on moving material; gravity is a force, not the mechanism of heat transfer.

Convection is energy transfer through currents created in liquids and gases by temperature differences. When part of the fluid is heated, it expands, becomes less dense, and rises. Cooler, denser fluid moves in to take its place and sinks, forming a continuous loop that carries heat with it. This bulk movement explains phenomena like boiling water, warm air rising from a heater, and big-scale atmospheric and ocean currents. Conduction, by contrast, moves energy through direct particle contact without bulk motion; radiation transfers energy via electromagnetic waves and doesn’t rely on moving material; gravity is a force, not the mechanism of heat transfer.