Question

explain all three methods of heat transfers​

Answer 1

Heat is transfered via solid material (conduction), liquids and gases (convection), and electromagnetical waves (radiation). Heat is usually transfered in a combination of these three types and seldomly occurs on its own. For example, the thermal environment of a building is influenced by heat fluxes through the ground (conduction), and the building envelope (mostly convection and radiation).

Answer 2

• Conduction is heat transfer through stationary matter by physical contact. (The matter is stationary on a macroscopic scale—we know there is thermal motion of the atoms and molecules at any temperature above absolute zero.) Heat transferred between the electric burner of a stove and the bottom of a pan is transferred by conduction.

• Convection is the heat transfer by the macroscopic movement of a fluid. This type of transfer takes place in a forced-air furnace and in weather systems, for example.

• Heat transfer by radiation occurs when microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed. An obvious example is the warming of the Earth by the Sun. A less obvious example is thermal radiation from the human body.