Two coils, $X$ and $Y$, are kept in close vicinity of each other. When a varying current, $I(t)$, flows through coil $X$, the induced emf $(V(t))$ in coil $Y$, varies in the manner shown here. The variation of $I(t)$; with time, can then be represented by the graph labelled as graph

Explain mutual induction and derive equation of mutual $\mathrm{emf}$.

A circular loop ofradius $0.3\ cm$ lies parallel to amuch bigger circular loop ofradius $20\ cm$. The centre of the small loop is on the axis of the bigger loop. The distance between their centres is $15\ cm$. If a current of $2.0\ A$ flows through the smaller loop, then the flux linked with bigger loop is

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

In $SI$, Henry is the unit of

Two circuits have coefficient of mutual induction of $0.09$ $henry$. Average $e.m.f$. induced in the secondary by a change of current from $0$ to $20$ $ampere$ in $0.006$ $second$ in the primary will be......$V$