Two charges ${q_1}$ and ${q_2}$ are placed at $(0, 0, d)$ and$(0, 0, – d)$ respectively. Find locus of points where the potential is zero.

Figure shows a solid hemisphere with a charge of $5\ nC$ distributed uniformly through its volume. The hemisphere lies on a plane and point $P$ is located on this plane, along a radial line from the centre of curvature at distance $15\ cm$. The electric potential at point $P$ due to the hemisphere, is …..$V$

The election field in a region is given by $\vec E = (Ax + B)\hat i$ where $E$ is in $N\,C^{-1}$ and $x$ in meters. The values of constants are $A = 20\, SI\, unit$ and  $B = 10\, SI\, unit$. If the potential at $x =1$ is $V_1$ and that at $x = -5$ is $V_2$ then $V_1 -V_2$ is…..$V$

The potential at a distance $R/2$ from the centre of a conducting sphere of radius $ R$ will be

Charges are placed on the vertices of a square as shown. Let $E$ be the electric field and $V$ the potential at the centre. If the charges on $A$ and $B$ are interchanged with those on $D$ and $C$ respectively, then