Q 12-06-090JEE MainJEE Main 2022 (25 Jun, Shift 1)Easy
The current in a coil of self inductance $L = 2.0\ \text{H}$ is increasing according to the law $i = 2\sin t^2$. Find the amount of energy spent (in J) during the period when the current changes from $0$ to $2\ \text{A}$.
Numerical value type. Enter your answer.
Answer: 4
The energy spent goes into the magnetic field of the coil:
$$U = \frac12Li^2 = \frac12\times2\times(2)^2 = 4\ \text{J}$$
Solution by Sreeraj P, M.Sc Physics