Two discs $A$ and $\mathrm{B}$ are mounted coaxially on a vertical axle. The discs have moments of inertia $I$ and $2 I$ respectively about the common axis. Disc $\mathrm{A}$ is imparted an initial angular velocity $2 \omega$ using the entire potential energy of a spring compressed by a distance $x_1$. Disc $B$ is imparted an angular velocity $\omega$ by a spring having the same spring constant and compressed by a distance $x_2$. Both the discs rotate in the clockwise direction.
$1.$ The ratio of $x_1 / x_2$ is
$(A)$ $2$ $(B)$ $\frac{1}{2}$ $(C)$ $\sqrt{2}$ $(D)$ $\frac{1}{\sqrt{2}}$
$2.$ When disc $\mathrm{B}$ is brought in contact with disc $\mathrm{A}$, they acquire a common angular velocity in time $\mathrm{t}$. The average frictional torque on one disc by the other during this period is
$(A)$ $\frac{2 \mathrm{I} \omega}{3 \mathrm{t}}$ $(B)$ $\frac{9 \mathrm{I} \omega}{2 \mathrm{t}}$ $(C)$ $\frac{9 \mathrm{I} \omega}{4 \mathrm{t}}$ $(D)$ $\frac{3 \mathrm{I} \omega}{2 \mathrm{t}}$
$3.$ The loss of kinetic energy during the above process is
$(A)$ $\frac{\mathrm{I} \omega^2}{2}$ $(B)$ $\frac{\mathrm{I} \omega^2}{3}$ $(C)$ $\frac{\mathrm{I} \omega^2}{4}$ $(D)$ $\frac{\mathrm{I} \omega^2}{6}$
Give the answer question $1,2$ and $3.$