Radio frequency choke uses a core of

Write down the names of two devices which work on the principle of electromagnetic induction.

$A$ 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 $\text{m s}^{-1}$	$(4)$ $0.12$
	$(5)$ $2.00$

An inductance of $2\,H$ carries a current of $2\,A$. To prevent sparking when the circuit is broken,a capacitor of $4\,\mu F$ is connected across the inductance. The voltage rating of the capacitor is of the order of

$A$ short bar magnet passes at a steady speed right through a long solenoid. $A$ galvanometer is connected across the solenoid. Which graph best represents the variation of the galvanometer deflection $\theta$ with time $t$?

$A$ square loop of side $1 \, m$ is placed in a perpendicular magnetic field. Half of the area of the loop is inside the magnetic field. $A$ battery of $emf$ $10 \, V$ and negligible internal resistance is connected in the loop. The magnetic field changes with time according to the relation $B = (0.01 - 2t) \, Tesla$. The resultant $emf$ in the loop will be.....$V$