With the decrease of current in the primary coil from $2\,A$ to zero in $0.01\,s$,the $emf$ generated in the secondary coil is $1000\,V$. The mutual inductance of the two coils is......$H$.

Give two definitions of mutual inductance, give its units and write factors on which its value depends.

Two coils are kept near each other. When no current passes through the first coil and the current in the $2^{nd}$ coil increases at the rate of $10 \,A/s$, the e.m.f. in the $1^{st}$ coil is $20 \,mV$. When no current passes through the $2^{nd}$ coil and $3.6 \,A$ current passes through the $1^{st}$ coil, the flux linkage in coil $2$ is:

The induction coil works on the principle of

$A$ coil of radius $r$ is placed on another coil (whose radius is $R$ and current flowing through it is changing) so that their centres coincide. $(R \gg r)$ If both the coils are coplanar,then the mutual inductance between them is proportional to

An $e.m.f.$ of $100$ $mV$ is induced in a coil when the current in another nearby coil changes from $0$ to $10$ $A$ in $0.1$ $s$. The coefficient of mutual induction between the two coils is $...$ $mH$.