JEE PYQ: Alternating Current Question 9
Question 9 - 2021 (18 Mar Shift 2)
In a series LCR circuit, the inductive reactance ($X_L$) is $10\Omega$ and the capacitive reactance ($X_C$) is $4\Omega$. The resistance ($R$) in the circuit is $6\Omega$. The power factor of the circuit is:
(a) $\frac{1}{2}$ (b) $\frac{1}{2\sqrt{2}}$ (c) $\frac{1}{\sqrt{2}}$ (d) $\frac{\sqrt{3}}{2}$
Show Answer
Answer: (c)
Solution
$Z = \sqrt{R^2 + (X_L - X_C)^2} = \sqrt{6^2 + (10-4)^2} = 6\sqrt{2}$. $\cos\phi = \frac{R}{Z} = \frac{6}{6\sqrt{2}} = \frac{1}{\sqrt{2}}$.
BETA
