$64$ charged drops coalesce to form a bigger charged drop. The potential of bigger drop will be ...... times that of smaller drop:

At a certain distance from a point charge, the electric field is $500 \mathrm{V} {\mathrm{m}}^{-1}$ and the potential is $3000 \mathrm{V}$. What is the distance?

Figure represents a square carrying charges $+q,+q,-q,-q$ at its four corners as shown. Then the potential will be zero at points

The potential difference between points $A$ and $B$ in the given uniform electric field is: