Exercise 1

A vertical conducting ring of radius $R$ falls vertically with a speed $v$ in a horizontal uniform magnetic field $B$ which is perpendicular to the plane of the ring. Then

Two identical conducting rings $A \& B$ of radius $R$ are in pure rolling over a horizontal conducting plane with the same speed (of centre of mass) $v$ but in opposite directions. A constant magnetic field $B$ is present pointing inside the plane of paper(ring). Then the potential difference between the highest points of the two rings is

An inductor $L$ and a resistor $R$ are connected in series with a direct current source of $\mathrm{emf} E$. The maximum rate at which energy is stored in the magnetic field is

In the circuit shown in figure, the switch $S$ was initially at position $1$. After a sufficiently long time, the switch $S$ was thrown from position $1$ to position $2$. The voltage drop across the resistor at that instant is

As shown in the figure, the key $K$ is closed, the direction of the induced current in the coil $B$ will be

A copper ring is tied to a string and suspended vertically. On bringing a magnet towards the ring, as shown in the figure

The graph between the current and the time for an inductance coil is shown below. Which of the following graphs show the voltage-time variation

A metallic rod completes its circuit as shown in the figure. The circuit is normal to a magnetic field of $B=0.15 \mathrm{tesla}$. If the resistance of the rod is $3 \mathrm{\Omega }$ the force required to move the rod with a constant velocity of $2 \mathrm{m} {\mathrm{s}}^{-1}$ is