$1000$ small water drops each of radius $r$ and charge $q$ coalesce together to form one spherical drop. The potential of the big drop is larger than that of the smaller drop by a factor of

A hemispherical bowl of mass $m$ is uniformly charged with charge density $'\sigma '$ . Electric potential due to charge distribution at a point $'A'$ is (which lies at centre of radius as shown).

Consider the points lying on a straight line joining two fixed opposite charges. Between the charges there is

A solid conducting sphere having a charge $Q$ is surrounded by an uncharged concentric conducting hollow spherical shell. Let the potential difference between the surface of the solid sphere and that of the outer surface of the hollow shell be $V$. If the shell is now given a charge of $-3Q$, the new potential difference between the same two surfaces is......$V$

A spherical conductor of radius $2\,m$ is charged to a potential of $120\,V.$ It is now placed inside another hollow spherical conductor of radius $6\,m.$ Calculate the potential to which the bigger sphere would be raised......$V$

Draw a graph for variation of potential $\mathrm{V}$ with distance $\mathrm{r}$ for a point charge $\mathrm{Q}$.