Q 12-06-135JEE MainJEE Main 2019 (9 Apr, Shift 2)Easy
Two coils P and Q are separated by some distance. When a current of $3\ \text{A}$ flows through coil P, a magnetic flux of $10^{-3}\ \text{Wb}$ passes through Q. No current is passed through Q. When no current passes through P and a current of $2\ \text{A}$ passes through Q, the flux through P is
Answer: (B) $6.67\times10^{-4}\ \text{Wb}$
Mutual inductance is the same both ways: $M = \dfrac{10^{-3}}{3}\ \text{H}$.
$$\Phi_P = MI_Q = \frac{10^{-3}}{3}\times2 \approx 6.67\times10^{-4}\ \text{Wb}$$
Solution by Sreeraj P, M.Sc Physics