$A$ series $LR$ circuit is connected to a voltage source with $V(t) = V_0 \sin \omega t$. After a very large time,how does the current $I(t)$ behave? (Given: $t_0 \gg \frac{L}{R}$)

The self-inductance of a choke coil is $10\, mH$. When it is connected to a $10\, V$ $dc$ source,the power loss is $20\, W$. When it is connected to a $10\, V$ $ac$ source,the power loss is $10\, W$. The frequency of the $ac$ source is......$Hz$.

Three alternating voltage sources $V_1 = 3 \sin \omega t \text{ V}$,$V_2 = 5 \sin(\omega t + \phi_1) \text{ V}$,and $V_3 = 5 \sin(\omega t - \phi_2) \text{ V}$ are connected in series with a resistor $R = \sqrt{\frac{7}{3}} \, \Omega$ as shown in the figure (where $\phi_1 = 30^\circ$ and $\phi_2 = 127^\circ$). Find the peak current (in Ampere) through the resistor.

Statement-$I$: $A$ capacitor can be used in an $a.c.$ circuit in place of a choke coil.
Statement-$II$: $A$ capacitor blocks $d.c.$ and allows $a.c.$ to pass.

Give the name of the physical quantity in an $LCR$ circuit that corresponds to the damping constant in forced oscillations.

The figure shows a system of an inductor and a parallel plate capacitor made of $2$ parallel circular plates of area $A$,filled with a dielectric liquid of dielectric constant $K$. $A$ small leak develops in the capacitor,and the liquid starts to fill the inductor of the same dimensions having $n$ turns per unit length. Find the ratio of the magnitude of the initial reactance to the final reactance of the circuit after the liquid fills the inductor completely.
Given: $\omega^2 A^2 n^2 = c^2$
$\omega \rightarrow$ angular frequency of $AC$
$c \rightarrow$ speed of light
$\mu_r \rightarrow$ relative permeability of the liquid