V(t) = ωL I

_{m}cos ωt
V(t) = X

_{L}I_{m}cos ωt
Where; X

_{L}= ωL; X_{L}is known as inductance of circuit and has a unit of “ohm”.
V(t) = XLI

_{m}sin (ωt + 90⁰)
And instantaneous power

p(t) = v (t) * i(t)

= V

_{m}cos ωt I_{m}sin ωt
So average power is

Hence in positive half cycle of the power, inductor takes energy
from the source and in the negative cycle inductor delivers energy to the
source. Hence not power dissipation is zero.

From above mathematical expressions we can draw phasor diagram of
rms value of voltage and current.