$A$ 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?

$A$ coil of effective area $3 \,m^2$ is placed at right angles to a magnetic field of induction $0.05 \,Wb/m^2$. If the field is decreased to $20 \%$ of its original value in $10 \,s$, the e.m.f. induced in the coil will be: (in $\,mV$)

The magnetic flux through a coil of resistance $10\,\Omega$ is changed by $\Delta \phi$ in $0.1\,s$. The resulting current in the coil varies with time as shown in the figure. Then,the magnitude $\left| \Delta \phi \right|$ is equal to (in weber):

As shown in the figure,a bar magnet is moving towards a stationary coil with a constant speed $v$. The direction of the induced current in the coil as observed by the observer on the $R$.$H$.$S$. is . . . . . . .

$A$ wire of irregular shape is turning into a circular shape in a magnetic field which is directed into the paper. The direction of the induced current is

$A$ current-carrying infinitely long wire is kept along the diameter of a circular wire loop,without touching it. The correct statement$(s)$ is (are):
$(A)$ The emf induced in the loop is zero if the current is constant.
$(B)$ The emf induced in the loop is finite if the current is constant.
$(C)$ The emf induced in the loop is zero if the current decreases at a steady rate.
$(D)$ The emf induced in the loop is finite if the current decreases at a steady rate.