An alternating voltage \( V = V_0\sin(\omega t + \pi/2) \) is applied across an ac circuit. As a result, a current \( I = I_0\sin(\omega t + \pi/6) \) flows in it. The power factor of the circuit is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \( 0.5 \)
The power factor of an a.c. circuit is \( \cos\phi \), where \( \phi \) is the phase difference between the voltage and the current.
\( \displaystyle \phi = \left(\omega t + \frac{\pi}{2}\right) - \left(\omega t + \frac{\pi}{6}\right) = \frac{\pi}{3} \)
\( \displaystyle \cos\phi = \cos 60^\circ = 0.5 \)