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 $L_2$ :

An ac voltmeter connected between points $A$ and $B$ in the circuit below reads $36 \mathrm{V}$. If it is connected between $A$ and $C$, the reading is $39 \mathrm{V}$. The reading when it is connected between $B$ and is $D$ $25 \mathrm{V}$. What will the voltmeter read when it is connected between $A$ and $D?$) Assume that the voltmeter reads true rms voltage values and that the source generated a pure ac.)

In the circuit shown below, all the inductors (assumed ideal) and resistors are identical. The current through the resistance on the right is $I$ after the key $K$ has been switched on for a long time. The currents through the three resistors(in order, from left to right) immediately after the key is switched off are: 

A conducting bar of mass $m$ and length $l$ moves on two frictionless parallel rails in the presence of a constant uniform magnetic field of magnitude $B$ directed into the page as shown in the figure. The bar is given an initial velocity $v_{\circ }$ towards the right at $t=0$. Then the

A square-shaped conducting wire loop of dimension a moving parallel to the $x$-axis approaches a square region of size $b\left(a<b\right)$ where a uniform magnetic field $B$ exists pointing into the plane of the paper (see figure). As the loop passes through this region, the plot correctly depicting its speed $\left(v\right)$ as a function of $x$ is