Which process causes warm air to rise in a room?

Which process causes warm air to rise in a room?

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

Answer: (B)

Convection is the process at work. When air is heated near a heat source, it becomes less dense than the surrounding cooler air, so it rises. As it rises, it cools, becomes denser, and sinks, creating a circular pattern called a convection current. In a room, this means warm air from a heater tends to rise toward the ceiling while cooler air moves in to take its place, sustaining the circulation. Conduction would transfer heat mainly by direct contact, warming nearby surfaces or air without creating the rising movement. Radiation transfers heat through waves from the source to objects, and doesn’t by itself describe the vertical rise of air. Reflection is just the bouncing of waves and isn’t a heat-transfer mechanism in this context.

Convection is the process at work. When air is heated near a heat source, it becomes less dense than the surrounding cooler air, so it rises. As it rises, it cools, becomes denser, and sinks, creating a circular pattern called a convection current. In a room, this means warm air from a heater tends to rise toward the ceiling while cooler air moves in to take its place, sustaining the circulation.

Conduction would transfer heat mainly by direct contact, warming nearby surfaces or air without creating the rising movement. Radiation transfers heat through waves from the source to objects, and doesn’t by itself describe the vertical rise of air. Reflection is just the bouncing of waves and isn’t a heat-transfer mechanism in this context.