The power factor of an a.c. circuit having resistance r and inductance L connected in series to an a.c. source of angular frequency ω is
Answer & explanation
Correct answer: option 3
$\text{Power Factor is } cos\phi = \frac{R}{Z} = \frac{R}{\sqrt{R^2 + X_L^2}} = \frac{R}{\sqrt{R^2 + \omega^2L^2}}$