$A$ magnetic field of flux density $1.0 \,Wb \,m^{-2}$ acts normal to a $80$ turn coil of $0.01 \,m^2$ area. If this coil is removed from the field in $0.2 \,s$, then the emf induced in it is (in $\,V$)

$A$ uniform magnetic field is restricted within a region of radius $r$. The magnetic field changes with time at a rate $\frac{d\vec{B}}{dt}$. Loop $1$ of radius $R > r$ encloses the region,and loop $2$ of radius $R$ is outside the region of the magnetic field as shown in the figure. Then the $e.m.f.$ generated is:

In the following figure,the magnet is moved towards the coil with a speed $v$ and the induced $emf$ is $e$. If the magnet and the coil recede away from one another,each moving with speed $v$,the induced $emf$ in the coil will be: (Assume the separation in both cases is the same)

The graph shows the variation in magnetic flux $\phi(t)$ with time through a coil. Which of the statements given below is not correct?

The magnetic flux linked with a coil at any instant $t$ is given by $\phi = 5t^3 - 100t + 300$. The $e.m.f.$ induced in the coil at $t = 2 \ s$ is $....... \ V$.

Consider a metal ring kept (supported by a cardboard) on top of a fixed solenoid carrying a current $I$ as per the figure. The centre of the ring coincides with the axis of the solenoid. If the current in the solenoid is switched off,what will happen to the ring?