Q 12-06-034JEE MainJEE Main 2026 (5 Apr, Shift 1)Medium
In the given circuit below inductance values of $L_1, L_2$ and $L_3$ are same. The magnetic energy stored in the entire circuit is $(U_t)$ and that stored in the $L_2$ inductor is $(U_l)$. $U_t/U_l$ is ______.
(Ignore the mutual inductance if any)
Numerical value type. Enter your answer.
Answer: 6
$L_1$ carries the full current $I$; $L_2$ and $L_3$ are identical and in parallel, so each carries $I/2$.
$$U_t = \frac{1}{2}LI^2 + 2 \times \frac{1}{2}L\left(\frac{I}{2}\right)^2 = \frac{1}{2}LI^2 \times \frac{3}{2}, \qquad U_l = \frac{1}{2}LI^2 \times \frac{1}{4}$$
$\dfrac{U_t}{U_l} = 6$.
Solution by Sreeraj P, M.Sc Physics