If a copper ring is moved quickly towards the south pole of a powerful stationary bar magnet,then:

$A$ current-carrying solenoid is approaching a conducting loop as shown in the figure. The direction of the induced current as observed by an observer on the other side of the loop will be

Consider a metal ring kept on top of a fixed solenoid (say on a cardboard) as per the figure. The center of the ring coincides with the axis of the solenoid. If the current is suddenly switched on,the metal ring jumps up. Explain.

The flux associated with a closed loop is $\phi = 3t^2 + 2t + 5 \text{ Wb}$. If the resistance of the loop is $14 \ \Omega$,then the current induced in this coil at $t = 2 \text{ s}$ is . . . . . . . (in $\text{ A}$)

$A$ cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis,then

$A$ magnetic field $B$ is confined to a region $r \le a$ and points out of the paper (the $z$-axis),$r = 0$ being the centre of the circular region. $A$ charged ring (charge $= Q$) of radius $b$,$b > a$ and mass $m$ lies in the $xy$-plane with its centre at the origin. The ring is free to rotate and is at rest. The magnetic field is brought to zero in time $\Delta t$. Find the angular velocity $\omega$ of the ring after the field vanishes.