Two circular coils $P$ and $Q$ are fixed coaxially and carry currents $I_1$ and $I_2$ respectively.

Two metallic rings $A$ and $B$,identical in shape and size but having different resistivities $\rho_A$ and $\rho_B$,are kept on top of two identical solenoids as shown in the figure. When current $I$ is switched on in both the solenoids in an identical manner,the rings $A$ and $B$ jump to heights $h_A$ and $h_B$,respectively,with $h_A > h_B$. The possible relation$(s)$ between their resistivities and their masses $m_A$ and $m_B$ is(are):
$(A)$ $\rho_A > \rho_B$ and $m_A = m_B$
$(B)$ $\rho_A < \rho_B$ and $m_A = m_B$
$(C)$ $\rho_A > \rho_B$ and $m_A > m_B$
$(D)$ $\rho_A < \rho_B$ and $m_A < m_B$

$A$ 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:

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

$A$ wire loop is placed in a region of time-varying magnetic field which is oriented orthogonally to the plane of the loop as shown in the figure. The graph shows the magnetic field variation as a function of time. Assume the positive $emf$ is the one which drives a current in the clockwise direction as seen by the observer in the direction of $B$. Which of the following graphs best represents the induced $emf$ as a function of time?

$A$ square loop of side $5 \, cm$ enters a magnetic field with a velocity of $1 \, cm/s$. The front edge enters the magnetic field at $t = 0$. Which graph best depicts the induced electromotive force $(emf)$ versus time?