Answer:
Electrical appliances at home transfer energy from the mains supply to heat and light our homes as well as to operate our appliances such as TV, Microwave and Computers etc.
The energy used is constant so a TV will use double the amount of energy in two hours as it will in one hour. The power of an electrical appliance tells us how much electrical energy it transfers in a second.
Power, P is measured in watts (W) where:
1 W = 1 J/s (joule/second).
Appliances used for heating have a much higher rating than those used to produce light or sound.
The amount of energy transferred from the mains appliance depends on the power rating of the appliance and the time for which it is switched on. Energy transferred from electricity is worked out by:
Energy = power × time
E = P × t