$A$ square coil $ABCD$ is placed in the $x-y$ plane with its centre at the origin. $A$ long straight wire,passing through the origin,carries a current in the negative $z$-direction. The current in this wire increases with time. The induced current in the coil is:

$A$ bar magnet falls from rest under gravity through the centre of a horizontal ring of conducting wire as shown in figure. Which of the following graph best represents the speed $(v)$ vs. time $(t)$ graph of the bar magnet?

Near a circular loop of conducting wire as shown in the figure,an electron moves along a straight line. The direction of the induced current,if any,in the loop is

$A$ very long solenoid of radius $R$ is carrying current $I(t) = kt e^{-\alpha t}$ $(k > 0)$,as a function of time $(t \geq 0)$. Counter-clockwise current is taken to be positive. $A$ circular conducting coil of radius $2R$ is placed in the equatorial plane of the solenoid and is concentric with the solenoid. The induced current in the outer coil as a function of time is correctly depicted by:

$A$ triangular wire frame (each side $= 2 \, m$) is placed in a region of time-variant magnetic field having $dB/dt = \sqrt{3} \, T/s$. The magnetic field is perpendicular to the plane of the triangle. The base of the triangle $AB$ has a resistance $1 \, \Omega$ while the other two sides have resistance $2 \, \Omega$ each. The magnitude of potential difference between the points $A$ and $B$ will be....$V$

The diagram below shows two coils $A$ and $B$ placed parallel to each other at a very small distance. Coil $A$ is connected to an ac supply. $G$ is a very sensitive galvanometer. When the key $K$ is closed: