$A$ coil having $N$ turns and resistance $R$ $\Omega$ is connected to a galvanometer of resistance $6R$ $\Omega$. The magnetic flux linked with this coil changes from $\phi_1$ weber to $\phi_2$ weber in time $t$ second. The induced current in the circuit is

$AB$ is a part of an electrical circuit (see figure). The potential difference $V_{A}-V_{B}$, at the instant when current $i=2 \text{ A}$ and is increasing at a rate of $1 \text{ A/s}$, is: (in $\text{ V}$)

$A$ coil of wire having finite inductance and resistance has a conducting ring placed coaxially within it. The coil is connected to a battery at time $t = 0$,so that a time-dependent current $I_1(t)$ starts flowing through the coil. If $I_2(t)$ is the current induced in the ring and $B(t)$ is the magnetic field at the axis of the coil due to $I_1(t)$,then as a function of time $(t > 0)$,the product $I_2(t) B(t)$:

$A$ flexible wire bent in the form of a circle is placed in a uniform magnetic field perpendicular to the plane of the coil. The radius of the coil changes as shown in the figure. The graph of induced $emf$ in the coil is represented by

An electron moves along the line $AB$,which lies in the same plane as a circular loop of conducting wires as shown in the diagram. What will be the direction of current induced,if any,in the loop?

$A$ conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced currents in wires $AB$ and $CD$ are