# The value of mutual inductance of two coils is 10 mH. If the current in one of the coil changes

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The value of mutual inductance of two coils is 10 mH. If the current in one of the coil changes from 5A to 1A in 0.2 s, calculate the value of emf induced in the other coil.

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Data: M = 10 mH = 10-2 H, I1i = 5A, I1f = 1 A,
∆t = 0.2s
The mutually induced emf in coil 2 due to the changing current in coil 1,
e21 = $$-M \frac{\Delta I_{1}}{\Delta t}=-M \frac{I_{1 \mathrm{f}}-I_{1 \mathrm{i}}}{\Delta t}$$
= -(10-2) $$\left(\frac{1-5}{0.2}\right)$$ = 0.2 V