A hemispherical bowl of mass $m$ is uniformly charged with charge density $'\sigma '$ . Electric potential due to charge distribution at a point $'A'$ is (which lies at centre of radius as shown).
$\frac{{\sigma R}}{{4{\varepsilon _0}}}$
$\frac{{\sigma R}}{{3{\varepsilon _0}}}$
$\frac{{\sigma R}}{{2{\varepsilon _0}}}$
$\frac{{\sigma R}}{{{\varepsilon _0}}}$
Figure shows three circular arcs, each of radius $R$ and total charge as indicated. The net electric potential at the centre of curvature is
Three charges $2 q,-q$ and $-q$ are located at the vertices of an equilateral triangle. At the center of the triangle
A uniform electric field of $400 \,v/m$ is directed $45^o$ above the $x$ - axis. The potential difference $V_A - V_B$ is -.....$V$
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 regular polygon of $n$ sides, each corner is at a distance $r$ from the centre. Identical charges are placed at $(n - 1)$ corners. At the centre, the intensity is $E$ and the potential is $V$. The ratio $V/E$ has magnitude.