Power is defined as the rate of transfer of energy. It is measured in watts (W), where 1W = 1 joule per second i.e. P = E / t.
In electrical circuits: P = VI
This is because;
1) Potential difference (V) is defined as the energy transferred per coulomb.
2) Current (I) is defined as the number of coulombs transferred per second
Therefore, p.d. x current is energy transferred per second i.e. power
The definition of resistance shows: V = IR
If this is combined with the previous equation different methods of calculating power can result;
P = VI,…