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ie, Power = Work done / Time taken

 

        or    P = W / t

where P = power

          W = work done

           t = time taken

In other words, power is the work done per unit time or power is the workdone per second.

We know that when work is done, an equal amount of energy is consumed.So,we can also define power by using the term 'energy' in place of work.Thus,power is also defined as the rate at which energy is consumed.

ie, Power = Energy consumed / Time taken

          or  P = E / t

where P = power

           E = energy consumed 

           t = time taken           

or in other words we can say that power is the rate at which work is done or energy is consumed.It is a scalar quantity which has only  magnitude but no direction.

The S.I. unit of power is watt which is denoted by the symbol 'W'.