In the given circuit,when does the lamp become momentarily bright?

$A$ metallic square wire loop of side $10\, cm$ and resistance $1\,\Omega$ is moved with a constant velocity $v_0$ in a uniform magnetic field of induction $B = 2\, T$ as shown in the figure. The magnetic field is perpendicular into the plane of the loop. The loop is connected to a network of resistors each of value $3\,\Omega$. The resistance of the lead wires $OS$ and $PQ$ are negligible. What should be the speed of the loop so as to have a steady current of $1\, mA$ in it? Give the direction of current in the loop.

On what factor does the induced current depend?

$A$ thin conducting rod $MN$ of mass $20 \text{ g}$,length $25 \text{ cm}$ and resistance $10 \text{ }\Omega$ is held on frictionless,long,perfectly conducting vertical rails as shown in the figure. There is a uniform magnetic field $B_0 = 4 \text{ T}$ directed perpendicular to the plane of the rod-rail arrangement. The rod is released from rest at time $t = 0$ and it moves down along the rails. Assume air drag is negligible. Match each quantity in List-$I$ with an appropriate value from List-$II$,and choose the correct option. [Given: The acceleration due to gravity $g = 10 \text{ m s}^{-2}$ and $e^{-1} = 0.4$]

List-$I$	List-$II$
$(P)$ At $t = 0.2 \text{ s}$,the magnitude of the induced emf in Volt	$(1)$ $0.07$
$(Q)$ At $t = 0.2 \text{ s}$,the magnitude of the magnetic force in Newton	$(2)$ $0.144$
$(R)$ At $t = 0.2 \text{ s}$,the power dissipated as heat in Watt	$(3)$ $1.20$
$(S)$ The magnitude of terminal velocity of the rod in $\text{m s}^{-1}$	$(4)$ $0.12$
	$(5)$ $2.00$

Column $I$ gives certain situations in which a straight metallic wire of resistance $R$ is used and Column $II$ gives some resulting effects. Match the statements in Column $I$ with the statements in Column $II$.

Column $I$	Column $II$
$(A)$ $A$ charged capacitor is connected to the ends of the wire	$(p)$ $A$ constant current flows through the wire
$(B)$ The wire is moved perpendicular to its length with a constant velocity in a uniform magnetic field perpendicular to the plane of motion	$(q)$ Thermal energy is generated in the wire
$(C)$ The wire is placed in a constant electric field that has a direction along the length of the wire	$(r)$ $A$ constant potential difference develops between the ends of the wire
$(D)$ $A$ battery of constant emf is connected to the ends of the wire	$(s)$ Charges of constant magnitude appear at the ends of the wire

In the figure,the switch $S$ is closed so that a current flows in the iron-core inductor which has inductance $L$ and the resistance $R$. When the switch is opened,a spark is obtained at the contacts. The spark is due to