What is the difference between energy and power? 

Energy is the ability to do work while power is the rate at which work is done.

Power=W/T

Here P is the power in Watts (W), W is the energy in Joules (J), and T is the time in seconds (s).

In terms of Electric Circuit,

P = I × V

where P is the power in Watts (W), I is the current

in Amperes (A), and V is the voltage in Volts (V).

For example say a current of 3A is drawn from a 9V battery then Power = 27 watts

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