Q 12-07-104JEE MainJEE Main 2022 (27 Jun, Shift 1)Easy
The current flowing through an ac circuit is given by $I = 5\sin(120\pi t)$ A. How long will the current take to reach the peak value starting from zero?
Answer: (D) $\dfrac{1}{240}$ s
The current first reaches its peak when $120\pi t = \dfrac{\pi}{2}$:
$$t = \frac{1}{240}\ \text{s}$$
(Equivalently, a quarter of the period $T = \dfrac{1}{60}$ s.)
Solution by Sreeraj P, M.Sc Physics