In an AC circuit the emf `(e)` and the current `(i)` at any instant are given respectively by,
`e =E_0 sin omega t and i = I_0 sin (omegat-phi)` The average power in the circuit over one cycle of AC is
Options:
(a) `(E_0I_0)/2`
(b) `(E_0I_0)/2 sin phi`
(c) `(E_0I_0)/2 cos phi`
(d) `E_0I_0`