Twenty-seven drops of the same size are charged at $220 \, V$ each. They combine to form a bigger drop. Calculate the potential of the bigger drop (in $V$).

In the circuit shown in the following figure,the potential difference across the $3 \mu F$ capacitor is: (in $V$)

Five similar condenser plates,each of area $A$,are placed at equal distance $d$ apart and are connected to a source of $e.m.f.$ $V$ as shown in the diagram. The charge on the plates $1$ and $4$ will be:

Two positrons $(e^+)$ and two protons $(p)$ are kept on four corners of a square of side $a$ as shown in the figure. The mass of a proton is much larger than the mass of a positron. Let $q$ denote the charge on the proton as well as the positron. Then,the kinetic energies of one of the positrons and one of the protons,respectively,after a very long time will be:

The capacities and connection of five capacitors are shown in the adjoining figure. The potential difference between the points $A$ and $B$ is $60\;V$. Then the equivalent capacity between $A$ and $B$ and the charge on $5\;\mu F$ capacitor will be respectively:

$A$ fully charged capacitor has a capacitance $C$. It is discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity $s$ and mass $m$. If the temperature of the block is raised by $\Delta T$,the potential difference $V$ across the capacitor is