Two isolated conducting spheres $S_{1}$ and $S_{2}$ of radius $\frac{2}{3} R$ and $\frac{1}{3} R$ have $12\, \mu C$ and $-3\, \mu C$ charges,respectively,and are at a large distance from each other. They are now connected by a conducting wire. $A$ long time after this is done,the charges on $S_{1}$ and $S_{2}$ are respectively:

Two capacitors of $10 \ pF$ and $20 \ pF$ are connected to $200 \ V$ and $100 \ V$ sources respectively. If they are connected by a wire,what is the common potential of the capacitors (in $V$)?

$A$ conducting body $1$ has some initial charge $Q$,and its capacitance is $C$. There are two other conducting bodies,$2$ and $3$,having capacitances $C_2 = 2C$ and $C_3 \rightarrow \infty$. Bodies $2$ and $3$ are initially uncharged. Body $2$ is touched with body $1$. Then,body $2$ is removed from body $1$ and touched with body $3$,and then removed. This process is repeated $N$ times. The charge on body $1$ at the end must be:

$A$ capacitor of capacitance $20 \mu F$ is charged by a battery of potential $24.3 \ V$. The capacitor is then disconnected from the battery and is connected to another uncharged capacitor of capacitance $10 \mu F$. After some time,the second capacitor is disconnected,discharged fully,and is again connected to the first capacitor. If the process is repeated several times,the charge on the first capacitor at the end of the fifth process is . . . . . . $\mu C$.

Two metal spheres of capacitance $C_1$ and $C_2$ carry some charges. They are put in contact and then separated. The final charges $Q_1$ and $Q_2$ on them will satisfy

Two metal spheres have radii of $20\, cm$ and $10\, cm$ respectively, and each sphere carries a charge of $150\, \mu C$. After connecting them with a conducting wire, the common potential on them will be: