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In an AC circuit having only a capacitor, the electric current _____ the voltage V in phase by ______.

Asked in GSEB Board July 2022 · Behaviour of R, L and C separately

Answer: (2) leads, π/2

Step-by-step solution

Given: V=V₀ sin ω t applied across a capacitor C.

Idea: the charge follows the voltage, q=CV=CV₀ sin ω t, and the current is its rate of change.

I=(dq)/(dt)=ω CV₀ cos ω t=I₀ sin (ω t+π/2).

The current reaches its peak a quarter cycle before the voltage does.

So the current leads the voltage by π/2.

Why the other options are wrong

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