$A$ magnetic field of $2 \times 10^{-2} \, T$ acts at right angles to a coil of area $100 \, cm^2$ with $50$ turns. The average emf induced in the coil is $0.1 \, V$,when it is removed from the field in time $t$. The value of $t$ is $... \, sec$.

Magnetic flux in a circuit containing a coil of resistance $2\,\Omega$ changes from $2.0\,Wb$ to $10\,Wb$ in $0.2\,s$. The charge passed through the coil in this time is......$C$

$A$ 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.

$A$ bar magnet is moved along the axis of a copper ring placed far away from the magnet. Looking from the side of the magnet,an anticlockwise current is found to be induced in the ring. Which of the following may be true?

Two identical metallic square loops $L_1$ and $L_2$ are placed next to each other with their sides parallel on a smooth horizontal table. Loop $L_1$ is fixed and a current which increases as a function of time is passed through it. Then,loop $L_2$ is

$A$ copper ring having a cut such as not to form a complete loop is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring as shown in figure. The acceleration of the falling magnet is ($g=$ acceleration due to gravity)