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
Concept. Energy in an inductor is $\frac12LI^2$. Identical parallel inductors (no resistance) share the current equally.
Step 1. Currents. $I$ through $L_1$, $\dfrac I2$ through each of $L_2$, $L_3$.
Step 2. Energies. $U_t=\dfrac12LI^2+2\times\dfrac12L\dfrac{I^2}{4}=\dfrac34LI^2$; $U_l=\dfrac18LI^2$.
Step 3. Ratio. $\dfrac{U_t}{U_l}=6$.
Answer. $6$.
Solution by Sreeraj P, M.Sc Physics
