The mutual inductance of a pair of coils, each of ' $\mathrm{N}$ ' turns, is ' $\mathrm{M}$ ' henry. If a…
The mutual inductance of a pair of coils, each of ' $\mathrm{N}$ ' turns, is ' $\mathrm{M}$ ' henry. If a current of ' $\mathrm{I}$ ' ampere in one of the coils is brought to zero in ' $\mathrm{t}$ ' second, the e. m. f. induced per turn in the other coil in volt is
$\frac{\text { MI }}{t}$
$\frac{\mathrm{NMI}}{\mathrm{t}}$
$\frac{\mathrm{NM}}{\mathrm{It}}$
$\frac{\mathrm{MI}}{\mathrm{Nt}}$
Solution
Emf induced due to mutual inductance per coil, $\mathrm{e}=\frac{\mathrm{M} \Delta \mathrm{I}}{\Delta \mathrm{t}}$
Here, the current changes from I to zero in time $\mathrm{t}$ seconds.
$\therefore \quad \mathrm{e}=\frac{\mathrm{MI}}{\mathrm{t}}$