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

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.....$millihenry$

If a change in current of $0.01\, A$ in one coil produces a change in magnetic flux of $1.2 \times {10^{ - 2}}\,Wb$ in the other coil, then the mutual inductance of the two coils in henries is.....$H$

In a $dc$ motor, induced $e.m.f.$ will be maximum

Two conducting circular loops of radii $R_1$ and $R_2$ are placed in the same plane with their centre coinciding. If $R_1 >> R_2$ the mutual inductance $M$ between them will be directly proportional to

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