If an iron rod is placed inside a coil, what happens to the induced current?

The switch $S$ shown in the circuit is closed at $t=0$. The ratio of the current drawn from the battery by the circuit at $t=0$ and $t=\infty$ is:

The circuit shown in the figure contains an inductor $L = 25 \text{ mH}$, a capacitor $C_0 = 10 \text{ } \mu\text{F}$, a resistor $R_0 = 5 \text{ } \Omega$ and an ideal battery of $20 \text{ V}$. The circuit also contains two keys $K_1$ and $K_2$. Initially, both the keys are open and there is no charge on the capacitor. At an instant, key $K_1$ is closed and immediately after this, the current in $R_0$ is found to be $I_1$. After a long time, the current attains a steady state value $I_2$. Thereafter, $K_2$ is closed and simultaneously $K_1$ is opened, and the voltage across $C_0$ oscillates with amplitude $V_0$ and angular frequency $\omega_0$. Match the quantities mentioned in $List-I$ with their values in $List-II$ and choose the correct option.

$List-I$	$List-II$
$(P)$ The value of $I_1$ in Ampere is	$(1)$ $0$
$(Q)$ The value of $I_2$ in Ampere is	$(2)$ $2$
$(R)$ The value of $\omega_0$ in kilo-radians/s is	$(3)$ $4$
$(S)$ The value of $V_0$ in Volt is	$(4)$ $20$
	$(5)$ $200$

On what factor does the induced current depend?

$A$ square loop of side $0.1 \, m$ and resistance $1 \, \Omega$ is moved with a constant velocity in a magnetic field of $2 \, Wb/m^2$. If a current of $1 \, mA$ is induced in the circuit, what is the velocity of the loop in $cm/sec$? (The external circuit consists of a Wheatstone bridge with five $3 \, \Omega$ resistors as shown in the figure.)

$A$ circular insulated copper wire loop is twisted to form two loops of area $A$ and $2A$ as shown in the figure. At the point of crossing,the wires remain electrically insulated from each other. The entire loop lies in the plane of the paper. $A$ uniform magnetic field $\vec{B}$ points into the plane of the paper. At $t=0$,the loop starts rotating about the common diameter as an axis with a constant angular velocity $\omega$ in the magnetic field. Which of the following options is/are correct?
[$A$] The rate of change of the flux is maximum when the plane of the loops is perpendicular to the plane of the paper.
[$B$] The net emf induced due to both the loops is proportional to $\cos \omega t$.
[$C$] The emf induced in the loop is proportional to the sum of the areas of the two loops.
[$D$] The amplitude of the maximum net emf induced due to both the loops is equal to the amplitude of maximum emf induced in the smaller loop alone.