In electromagnetic induction,the induced $e.m.f.$ in a coil is independent of

$A$ flexible wire loop in the shape of a circle has a radius that grows linearly with time. There is a magnetic field perpendicular to the plane of the loop that has a magnitude inversely proportional to the distance from the center of the loop,i.e.,$B(r) \propto \frac{1}{r}$. How does the emf $E$ vary with time?

The working of a dynamo is based on the principle of

$A$ circular coil of area $2 \text{ cm}^2$ is placed in a magnetic field of $3 \text{ T}$ perpendicularly. The coil has $10$ turns and $5 \text{ } \Omega$ resistance. Now,the coil is removed from the magnetic field in $0.2 \text{ s}$. The value of induced charge flowing through the coil is . . . . . . .

The magnetic flux through a loop of resistance $10 \Omega$ varies according to the relation $\phi = 6t^2 + 7t + 1$,where $\phi$ is in milliweber and time is in seconds. At time $t = 1 \ s$,the induced e.m.f. is:

Lenz's law gives