Charge on the capacitor in the given circuit in steady state condition is :- ............... $\mu C$

Two thin conducting shells of radii $R$ and $3R$ are shown in the figure. The outer shell carries a charge $+Q$ and the inner shell is neutral. The inner shell is earthed with the help of a switch $S$.

$A$ parallel plate capacitor of capacity $100 \mu F$ is charged by a battery of $50 \text{ V}$. The battery remains connected and if the plates of the capacitor are separated so that the distance between them becomes double the original distance,the additional energy given by the battery to the capacitor in joules is

Find the heat produced in the capacitors on closing the switch $S$. (in $J$)

In the circuit shown,the steady state voltage across capacitor $C$ is a fraction of the battery e.m.f. $V$. The fraction is decided by:

$A$ soap bubble of radius $R$ and surface tension $T$ is formed in a vacuum. It is slowly charged so that it slowly expands. It stops charging when the radius becomes $2R$. Find the amount of charge given to the bubble.