$A$ spherical shell of radius $R$ carries a charge $Q$. What is the potential at point $B$ on the surface,at the center $A$,and at point $C$ at a distance $R/2$ from the center?

Two charges of magnitude $+q$ and $-3q$ are placed $100 \, cm$ apart. The distance from $+q$ between the charges where the electrostatic potential is zero is ....... $cm$.

Two positive charges $Q$ and $4Q$ are placed at points $A$ and $B$ respectively, where $B$ is at a distance $d$ units to the right of $A$. The total electric potential due to these charges is minimum at point $P$ on the line segment joining $A$ and $B$. What is the distance of $P$ from $A$?

The figure shows a positively charged infinite wire. $A$ particle of charge $q = 2 \, C$ moves from point $A$ to $B$ with constant speed. (Given linear charge density on the wire is $\lambda = 4 \pi \varepsilon_0$)

The electric potential inside a charged hollow conducting sphere is . . . . . . .

Two point charges of $1 \text{ nC}$ and $2 \text{ nC}$ are placed at two corners of an equilateral triangle of side $3 \text{ cm}$. The work done in bringing a charge of $3 \text{ nC}$ from infinity to the third corner of the triangle is . . . . . . $\mu\text{J}$. $( \frac{1}{4\pi\epsilon_{0}} = 9 \times 10^{9} \text{ N.m}^{2}/\text{C}^{2} )$