Q. An alternating current of frequency ‘$f$’ is flowing in a circuit containing a resistance $R$ and a choke $L$ in series. The impedance of this circuit is
A) $R + 2\pi fL$
B) $\sqrt{R^{2} + 4\pi^{2}f^{2}L^{2}}$
C) $\sqrt{R^{2} + L^{2}}$
D) $\sqrt{R^{2} + 2\pi fL}$
Explanation
(b) $Z = \sqrt{R^{2} + X_{L}^{2}},\ X_{L} = \omega L$ and $\omega = 2\pi f$
$\therefore Z = \sqrt{R^{2} + 4\pi^{2}f^{2}L^{2}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.