The mutual inductance of a pair of coils, each of $N\,turns$, is $M\,henry$. If a current of $I\, ampere$ in one of the coils is brought to zero in $t$ $second$ , the $emf$ induced per turn in the other coil, in volt, will be

There are $10$ turns in coil $M$ and $15$ turns in coil $N$ . If a current of $2\ A$ is passed through coil $M$ then the flux linked with coil $N$ is $1.8 × 10^{-3}\ Wb$ . If a current of $3\ A$ is passed through coil $N$ then flux linked with coil $M$ 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......$H$

A circular loop of radius $0.3\, cm$ lies parallel to a much bigger circular loop of radius $20 \,cm$. The centre of the small loop on the axis of the bigger loop. The distance between their centres is $15\, cm$. If a current of $20\, A$ flows through the smaller loop, then the flux linked with bigger loop is

The induction coil works on the principle of

Two circular coils can be arranged in any of the three situations shown in the figure. Their mutual inductance will be