Calculate the mutual inductance between two coils when a current of `4 A` changes to `12 A` in `0.5 s` in primary and induces an emf of `50 mV` in the secondary. Also, calculate the induced emf in the secondary if current in the primary changes from `3 A` to `9 A` is `0.02 s`.

Explanation

(a) `e=M(Deltai)/(Deltat)`
`50xx10^(-3)=(M(12-4))/(0.5)`
`M=3.125xx10^(-3)H=3.125mH`
(b) `e'=M(Deltai)/(Deltat)=(3.125xx10^(-3)xx(9-3))/(0.02)`
`0.9375V`