Electro Magnetic Induction And Alternating Currents Question 5
Question: 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 [CPMT 1978; MP PMT 1993; MP PET 1999; AIIMS 2000; Pb. PET 2004; RPET 2001, 03]
Options:
A) R + 2pfL
B) $ \sqrt{R^{2}+4{{\pi }^{2}}f^{2}L^{2}} $
C) $ \sqrt{R^{2}+L^{2}} $
D) $ \sqrt{R^{2}+2\pi fL} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ 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}} $
