$A$ spherical shell of radius $5 \ cm$ is charged to a potential of $10 \ V$ on its surface. The potential at the center of the shell will be ...... $V$.

In a certain charge distribution,all points having zero potential can be joined by a circle $S$. Points inside $S$ have positive potential and points outside $S$ have negative potential. $A$ positive charge,which is free to move,is placed inside $S$. What will happen to the charge?

An infinite number of charges,each equal to $0.2\,\mu C$,are arranged in a line at distances $1\,m, 2\,m, 4\,m, 8\,m, \dots$ from a fixed point. The potential at the fixed point is $......\,kV$.

If eight identical drops are joined to form a bigger drop,the potential on the bigger drop as compared to that on the smaller drop will be:

$A$ spherical shell with an inner radius $a$ and an outer radius $b$ is made of conducting material. $A$ point charge $+Q$ is placed at the centre of the spherical shell and a total charge $-q$ is placed on the shell. Assume that the electrostatic potential is zero at an infinite distance from the spherical shell. The electrostatic potential at a distance $R$ $(a < R < b)$ from the centre of the shell is (where $K = \frac{1}{4\pi\varepsilon_0}$):

Let $W$ joule be the work done to move an electric charge $q$ coulomb from a place $A$,where potential is $-5 \ V$,to another place $B$,where potential is $V$ volt. The value of $V$ is