Question

Under which of the following circumstances is heat transferred via convection?

a) as a jogger runs, heat generated in her body passes through fat cells under her skin before passing through her skin
b) the temperature of a black cast iron frying pan increases as sunlight shines on it
c) an electric heating pad is placed against ones back to soothe muscle ache
d) an electric heater warms the surrounding air causing it to circulate throughout the room
e) a steel disc is heated to 800 c within an air-evacuated furnace chamber

Answer 1

Heat transfer via convection occurs in option (d) where an electric heater warms the air around it, causing the air to circulate throughout the room.

Step-by-step explanation:

Heat is transferred via convection when there is a macroscopic movement of a fluid, such as air or water, due to temperature differences within the fluid. In the scenario provided, option (d) an electric heater warms the surrounding air causing it to circulate throughout the room is an example of heat being transferred by convection.

The electric heater warms the air, which then rises because it's less dense, while cooler air moves in to replace it, creating a cycle of warming and circulation of air throughout the room.