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 $t$ seconds,the e.m.f. induced per turn in the other coil in volt is:

$A$ circular current loop of radius $R$ is placed inside a square loop of side length $L$ $(L >> R)$ such that they are co-planar and their centers coincide. The permeability of free space is $\mu_0$. The mutual inductance between the circular loop and the square loop is . . . . . . .

$A$ long solenoid '$S$' has 'n' turns per meter,with diameter 'a'. At the centre of this coil we place a smaller coil of '$N$' turns and diameter 'b' (where $b < a$). If the current in the solenoid increases linearly with time,what is the induced emf appearing in the smaller coil? Plot a graph showing the nature of variation in emf,if current varies as a function of $I(t) = mt^2 + C$.

The emf induced in the secondary coil due to unit rate of change of current in the primary is called

If a current of $3.0 \ A$ flowing in the primary coil is reduced to zero in $0.001 \ s$,then the induced $e.m.f.$ in the secondary coil is $15000 \ V$. The mutual inductance between the two coils is (in $H$):

$A$ varying current at the rate of $3 \, A/s$ in a coil generates an $e.m.f.$ of $8 \, mV$ in a nearby coil. The mutual inductance of the two coils is: