Question

For wattless power in an AC circuit, the phase difference between the current and the voltage is -

• A. $0^{\circ }$
• B. ${90}^{\circ }$
• C. ${45}^{\circ }$
• D. Not possible

Answer 1

The correct option is B ${90}^{\circ }$

Wattless power means the average power consumed is zero.

So,

$P_{\text{avg}}=E_{\text{rms}}{i}_{\text{rms}}\cos \varphi =0$

$\Rightarrow \cos \varphi =0$

$\Rightarrow \varphi ={90}^{\circ }$

Therefore, the phase difference between the current and the voltage is ${90}^{\circ }$.

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