Q. An inductor of inductance $L$ and resistor of resistance $R$ are joined in series and connected by a source of frequency $\omega$. Power dissipated in the circuit is
A) $\frac{\left( R^{2} + \omega^{2}L^{2} \right)}{V}$
B) $\frac{V^{2}R}{(R^{2} + \omega^{2}L^{2})}$
C) $\frac{V}{\left( R^{2} + \omega^{2}L^{2} \right)}$
D) $\frac{\sqrt{R^{2} + \omega^{2}L^{2}}}{V^{2}}$
Explanation
(b) $P = Vi\cos\phi = V\left( \frac{V}{Z} \right)\left( \frac{R}{Z} \right) = \frac{V^{2}R}{Z^{2}} = \frac{V^{2}R}{(R^{2} + \omega^{2}L^{2})}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.