Question

The power factor of the following circuit is

• A. $\frac{1}{\sqrt{2}}$
• B. $\frac{\pi }{4}$
• C. $1$
• D. $\sqrt{2}$

Answer 1

The correct option is A $\frac{1}{\sqrt{2}}$

In series LCR circuit power factor is the ratio of resistance and impedance $\left(Z\right)$.

$Z=\sqrt{R^2+(X_L-X_c{)}^2}$

$\cos \varphi =\frac{R}{Z}=\frac{2}{\sqrt{2^2+(4-2{)}^2}}=\frac{1}{\sqrt{2}}$