The power factor of an AC circuit having resistance $R$ and inductance $L$ (connected in series) and an angular velocity $\omega$ is :

Question

( A ) $\frac{R}{(R^2 - \omega^2L^2)^{1/2}}$
( B ) $\frac{R}{(R^2 + \omega^2L^2)^{1/2}}$
( C ) $\frac{R}{\omega L}$
( D ) $\frac{\omega L}{R}$