A pair of adjacent coils having a mutual inductance, $M$. The current in one coil changes from 0 to $16…
A pair of adjacent coils having a mutual inductance, $M$. The current in one coil changes from 0 to $16 \mathrm{~A}$ in $0.3 \mathrm{~s}$ and the change of flux linkage with the other coil is $40 \mathrm{~Wb}$. The value of $M$ is
$0.4 \mathrm{H}$
$0.12 \mathrm{H}$
$2.5 \mathrm{H}$
$8.3 \mathrm{H}$
Solution
Coefficient of mutual induction between 2 coils is given by
$M=\frac{\text { Flux change in Ind coil }}{\text { Current change in Ist coil }}$
Given, flux change $=40 \mathrm{~Wb}$ and
current change $=16-0=16 \mathrm{~A}$
$\Rightarrow$ so, $\quad M=\frac{40}{16}=2.5 \mathrm{H}$