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Electric Power

Electric power is the rate at which electric energy is transferred by an electric circuit. The SI unit of power is a watt, or a joule per second.

Electric power is generally produced by electric generators but can also be supplied by chemical sources such as electric batteries. It is typically supplied to businesses and homes by the electric power industry. It is usually sold by a kilowatt hour. This is the product of power in kilowatt multiplied by the running time in hours.

Electric power is the rate of doing work. It is represented by the letter P. The electric power in watts produced by an electric current/consisting of a charge of Q coulombs every t seconds passing through an electric potential difference of V is

P = work done per unit time = QV/t = IV


Q is electric charge in coulombs

t is time in seconds

I is electric current in amperes

V is the electric potential or voltage in volts.

Electric power is transformed to other forms of power when electric charges move through an electric potential difference; this happens from a high voltage to a low voltage. The potential does work on the charges, converting the energy in the potential to kinetic energy of the charges, or some other form. This process occurs in most electrical appliances such as light bulbs, electric motors, and heaters. 

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