Write an equation for potential due to linear charge distribution. 

At the centre of a half ring of radius $R=10 \mathrm{~cm}$ and linear charge density $4 \mathrm{n} \mathrm{C} \mathrm{m}^{-1}$, the potential is $x \pi V$. The value of $x$ is  . . . . . 

Two thin concentric hollow conducting spheres of radii $R_1$ and $R_2$ bear charges $Q_1$ and $Q_2$ respectively. If $R_1 < R_2$, then the potential of a point at a distance $r$ from the centre $(R_1 < r < R_2)$ is

Derive an expression for electric potential at a point due to a system of $\mathrm{N}$ charges.

An electric field $\vec E\, = (25 \hat i + 30 \hat j)\,NC^{-1}$ exists in a region of space. If the potential at the origin is taken to be zero then the potential at $x\, = 2\, m, y\, = 2\, m$ is......$volt$

Electric field at a point $(x, y, z)$ is represented by $\vec E = 2x\hat i + {y^2}\hat j$ if potential at $(0,0,0)$ is $2\, volt$ find potential at $(1, 1, 1)$