Electro Magnetic Induction And Alternating Currents Question 41
Question: The coefficient of induction of a choke coil is 0.1H and resistance is $ 12,\Omega $ . If it is connected to an alternating current source of frequency 60 Hz, then power factor will be [RPET 1997]
Options:
A) 0.32
B) 0.30
C) 0.28
D) 0.24
Show Answer
Answer:
Correct Answer: B
Solution:
$ \cos \varphi =\frac{R}{Z}=\frac{R}{\sqrt{R^{2}+{{\omega }^{2}}L^{2}}} $ $ =\frac{12}{\sqrt{{{(12)}^{2}}+4\times {{\pi }^{2}}\times {{(60)}^{2}}\times {{(0.1)}^{2}}}} $
$ \Rightarrow \cos \varphi =0.30 $
