Question

For a series LCR circuit, power factor at resonance is equal to -

• A. $0.9$
• B. $0.5$
• C. $0.7$
• D. $1$

Answer 1

The correct option is D $1$

For a series LCR circuit, at resonance, $Z=R$.

Also, power factor,

$\cos \varphi =\frac{R}{Z}$

$\Rightarrow \cos \varphi =\frac{R}{R}=1$

Hence, option $\left(A\right)$ is the correct answer.