Two hollow metallic spheres of radii $20 \ cm$ and $10 \ cm$ each carry a charge of $150 \ \mu C$. If they are connected by a conducting wire,the common potential is ...... $V$.

When two isolated conductors $A$ and $B$ are connected by a conducting wire,positive charge will flow from:

$A$ sphere of radius $4 \ cm$ has a charge of $80 \ \mu C$ and a sphere of radius $6 \ cm$ has a charge of $40 \ \mu C$. If they are connected by a conducting wire,how much charge will flow from the $4 \ cm$ sphere to the $6 \ cm$ sphere?

In the circuit shown here $C_1 = 6\,\mu F$,$C_2 = 3\,\mu F$ and battery $B = 20\,V$. The switch $S_1$ is first closed. It is then opened and afterwards $S_2$ is closed. What is the charge finally on $C_2$ in $\mu C$?

$A$ capacitor of capacitance $6\ \mu F$ is charged to $100\, V$. It is then connected to another uncharged capacitor of capacitance $14\ \mu F$. Find the ratio of charges on the $6\ \mu F$ and $14\ \mu F$ capacitors and the potential across the $6\ \mu F$ capacitor.

$A$ capacitor of capacity $C_1$ is charged to a potential of $V_0$. After disconnecting it from the battery,it is connected to a neutral capacitor of capacity $C_2$ as shown in the adjoining figure. The ratio of the energy of the system before and after the connection of switch $S$ will be