In an ac circuit, the current leads the voltage by $\pi / 2$. The circuit is _________.
Fill in the blank with the correct answer from the options given below.
Answer & explanation
Correct answer: option 4
$ V = V_0 sin\omega t$
$\Rightarrow q = CV_0 sin \omega t $
$\Rightarrow I = \frac{dq}{dt} = CV_0\omega cos\omega t= CV_0sin(\omega t + \frac{\pi}{2})$
Current lead voltage by $\frac{\pi}{2}$. Hence the circuit is purely capacitive.
The correct answer is Option (4) → purely capacitive