If $n$ drops of the same size and same potential $V$ coalesce to form a single large drop,then the potential of the large drop will be .........

Initially $n$ identical capacitors are joined in parallel and are charged to potential $V$. Now they are separated and joined in series. Then

Initially,switch $S$ is connected to position $1$ for a long time as shown in the figure. The net amount of heat generated in the circuit after it is shifted to position $2$ is:

$A$ capacitor has a capacitance of $15\ \mu F$ when filled with a dielectric of constant $K = 15$. Another capacitor has a capacitance of $1\ \mu F$ when filled with air. Both capacitors are charged by a $100\ V$ battery. After removing the battery and the dielectric from the first capacitor,the two capacitors are connected in parallel. What will be the final voltage across them in $V$?

$A$ network of four capacitors with capacitances $C_1 = C$,$C_2 = 2C$,$C_3 = 3C$,and $C_4 = 4C$ is connected to a battery of potential $V$ as shown in the figure. The ratio of the charges on $C_2$ and $C_4$ is:

Two capacitors each of $1\,\mu F$ capacitance are connected in parallel and are then charged by a $200\,V$ $d.c.$ supply. The total energy of their charges (in $joules$) is