$A$ capacitor of capacity $4 \, \mu F$ is charged to $80 \, V$ and another capacitor of capacity $6 \, \mu F$ is charged to $30 \, V$. When they are connected, the energy lost by the $4 \, \mu F$ capacitor is: (in $ \, mJ$)

$A$ parallel plate capacitor of capacitance $C$ is charged to a potential difference $V$ by connecting it to a battery. Another capacitor of capacitance $2C$ is charged to a potential difference $2V$ by connecting it to another battery. Now,the charging batteries are removed and the capacitors are connected in parallel such that the positive plate of one is connected to the negative plate of the other and the negative plate of the first is connected to the positive plate of the second. Find the final energy of this configuration.

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

Two metallic charged spheres whose radii are $20\,cm$ and $10\,cm$ respectively,have each $150\,\mu C$ positive charge. The common potential after they are connected by a conducting wire is

Two capacitors $C_1$ and $C_2$ are charged to $120 \ V$ and $200 \ V$ respectively. It is found that connecting them together the potential on each one can be made zero. Then

Consider the situation shown in the figure. Capacitor $A$ has a charge $q$ on it,whereas $B$ is uncharged. The charge appearing on capacitor $B$ a long time after the switch $S$ is closed is