Draw a graph of $V \to r$ for spherical shell.

Value of potential at a point due to a point charge is

Six point charges are kept at the vertices of a regular hexagon of side $L$ and centre $O$, as shown in the figure. Given that $K=\frac{1}{4 \pi \varepsilon_0} \frac{q}{L^2}$, which of the following statement $(s)$ is (are) correct?

$(A)$ the elecric field at $O$ is $6 K$ along $O D$

$(B)$ The potential at $O$ is zero

$(C)$ The potential at all points on the line $PR$ is same

$(D)$ The potential at all points on the line $ST$ is same.

Four charges of $1\  \mu C, 2\  \mu C, 3\  \mu C,$ and $- 6\ \mu C$ are placed one at each corner of the square of side $1\,m$. The square lies in the $x-y$ plane with its centre at the origin.

Write an expressions for electric potential due to a continuous distribution of charges.

Three concentric metal shells $A, B$ and $C$ of respective radii $a, b$ and $c (a < b < c)$ have surface charge densities $+\sigma,-\sigma$ and $+\sigma$ respectively. The potential of shell $B$ is