Question

In an AC circuit, the power factor

• A. is unity when the circuit contains an ideal resistor only.
• B. is zero when the circuit contains an ideal inductor only.
• C. Both options $\left(A\right)$ and $\left(B\right)$
• D. None of these

Answer 1

The correct option is C Both options $\left(A\right)$ and $\left(B\right)$

The power factor of AC circuit is $\cos \varphi$.

For pure resistive AC circuit, $\varphi =0^{\circ }\Rightarrow \cos \varphi =1$

For pure inductive AC circuit, $\varphi ={90}^{\circ }\Rightarrow \cos \varphi =0$

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