Figure shows three circular arcs, each of radius $R$ and total charge as indicated. The net electric potential at the centre of curvature is

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 : 

Consider a finite insulated, uncharged conductor placed near a finite positively charged conductor. The uncharged body must have a potential

Uniform electric field of magnitude $100$ $V/m$ in space is directed along the line $y = 3 + x$. Find the potential difference between point $A$ $ (3, 1)$ $\&$ $B$ $(1, 3)$…….$V$

Two charges of $4\,\mu C$ each are placed at the corners $A$ and $B $ of an equilateral triangle of side length $0.2\, m $ in air. The electric potential at $C$ is $\left[ {\frac{1}{{4\pi {\varepsilon _0}}} = 9 \times {{10}^9}\,\frac{{N{\rm{ – }}{m^2}}}{{{C^2}}}} \right]$