Calculate the mutual inductance between two coils when a current of 4 A changing to 8 A in 0.5 s in one coil, induces an emf of 50 mV in the other coil.

Question

(A) $6.25 × 10^{−3}$ (B) $− 12.5 × 10^{−3}$ (C) $− 6.25 × 10^{−3}$ (D) $12.5 × 10^{−3}$