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ConvectionWhat is Convection?Convection is the transfer of thermal energy by means of currents in fluids (liquids or gases) only.
A convection current is the movement of fluid caused by the change in density in various parts of the fluid. When a fluid is heated, its mass remains constant but its volume expands. Its density decreases as p = m / V. Application(a) Air conditioner is always installed near to the ceiling of the room.
Reason: Cool air from the air conditioner, being denser, sinks. The warm air below, being less dense, rises and is drawn into the air conditioner where it is cooled. A convection current is set up and whole room is cooled to a desired temperature. (b) Heating element of an electric kettle is always placed at the bottom of the kettle. |
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