An $e.m.f.$ of $100\,millivolts$ is induced in a coil when the current in another nearby coil becomes $10\, ampere$ from zero in $0.1\,second$ . The coefficient of mutual induction between the two coils will be.....$millihenry$

Two coils of self inductance ${L_1}$ and ${L_2}$ are placed closer to each other so that total flux in one coil is completely linked with other. If $M$ is mutual inductance between them, then $M$ is

Mutual inductance of two coils can be increased by

Two coil $A$ and $B$ have coefficient of mutual inductance $M = 2H$. The magnetic flux passing through coil $A$ changes by $4$ Weber in $10$ seconds due to the change in current in $B$. Then

Two coils $P$ and $Q$ are separated by some distance. When a current of $3\, A$ flows through coil $P$ a magnetic flux of $10^{-3}\, Wb$ passes through $Q$. No current is passed through $Q$. When no current passes through $P$ and a current of $2\, A$ passes through $Q$, the flux through $P$ is

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