 Electric power

The instantaneous rate of energy transfer through a circuit port is $P(t)=V(t)I(t)$, with positive electric current entering the positive voltage terminal for the passive sign convention. Peak phasors in sinusoidal steady state give $⟨P⟩=\frac{1}{2}\mathrm{Re}(\tilde{V}{\tilde{I}}^{\ast })$. The factor $1/2$ is absent for root mean square phasors.

Electric power is the rate at which electrical energy is transferred or converted in an electrical circuit. It is typically measured in watts (W), where one watt is equal to one joule per second.