The electric potential at the surface of an atomic nucleus $(z=50)$ of radius $9 \times 10^{-13} \mathrm{~cm}$ is ________$\times 10^6 \mathrm{~V}$.

In a uniform electric field, the potential is $10$ $V $ at the origin of coordinates, and $8$ $V$ at each of the points $(1, 0, 0), (0, 1, 0) $ and $(0, 0, 1)$. The potential at the point $(1, 1, 1)$ will be....$V$

A hollow metal sphere of radius $5\, cm$ is charged so that the potential on its surface is $10\, V$. The potential at the centre of the sphere is

Write an equation for potential due to linear charge distribution. 

There are four concentric shells $A, B, C $ and $D $ of radii $ a, 2a, 3a$  and $4a$ respectively. Shells $B$ and $D$ are given charges $+q$ and $-q$ respectively. Shell $C$ is now earthed. The potential difference $V_A - V_C $ is : 

Three isolated equal charges are placed at the three comers of an equilateral triangle as shown in figure. The statement which is true for net electric potential $V$ and net electric field intensity $E$ at the centre of the triangle is