Two identical positive charges are placed at $x =\, -a$ and $x = a$ . The correct variation of potential $V$ along the $x-$ axis is given by

Shows that how the electrostatic potential varies with $\mathrm{r}$ for a point charge.

Calculate potential on the axis of a disc of radius $R$ due to a charge $Q$ uniformly distributed on its surface.

For given $\vec E = 2x\hat i + 3y\hat j$, find the potential at $(X, Y)$ if potential at origin is $5\, volts.$

Assertion : Two concentric charged shells are given. The potential difference between the shells depends on charge of inner shell.

Reason : Potential due to charge of outer shell remains same at every point inside the sphere.

As shown in the figure, charges $ + q$ and $ - q$ are placed at the vertices $B$ and $C$ of an isosceles triangle. The potential at the vertex $A$ is