$A$ radius of a spherical charged shell is $10 \ cm$ and the electric potential on its surface is $100 \ V$. Then,the potential at $2 \ cm$ from the centre of the shell will be $.......$ (in $V$)

The potential difference between the center and the surface of a sphere of radius $R$ with a uniform volume charge density $\rho$ within it will be:

Charges of $1 \mu C$ are placed at each of the four corners of a square of side $2 \sqrt{2} \text{ m}$. The potential at the point of intersection of the diagonals is . . . . . . .

Calculate the work done in taking a charge $q_0 = -2 \times 10^{-9} \, C$ from point $A$ to point $B$ via point $C$,as shown in the diagram. The source charge $q = 8 \, mC$ is located at the origin $O$. (in $, J$)

Two equal point charges are fixed at $x = -a$ and $x = +a$ on the $x$-axis. Another point charge $Q$ is placed at the origin. The change in the electrical potential energy of $Q$,when it is displaced by a small distance $x$ along the $x$-axis,is approximately proportional to

Identical charges $(-q)$ are placed at each corner of a cube of side $b$. The electrostatic potential energy of a charge $(+q)$ placed at the center of the cube is: