Two thin wire rings each having a radius $R$ are placed at a distance $d$ apart with their axes coinciding. The charges on the two rings are $ + q$ and $ - q$. The potential difference between the centres of the two rings is
Zero
$\frac{Q}{{4\pi {\varepsilon _0}}}\,\left[ {\frac{1}{R} - \frac{1}{{\sqrt {{R^2} + {d^2}} }}} \right]$
$QR/4\pi {\varepsilon _0}{d^2}$
$\frac{Q}{{2\pi {\varepsilon _0}}}\left[ {\frac{1}{R} - \frac{1}{{\sqrt {{R^2} + {d^2}} }}} \right]$
The radius of nucleus of silver (atomic number $=$ $47$) is $3.4 \times {10^{ - 14}}\,m$. The electric potential on the surface of nucleus is $(e = 1.6 \times {10^{ - 19}}\,C)$
Derive an expression for the electric potential in a electric field of positive point charge at distance $\mathrm{r}$.
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
Value of potential at a point due to a point charge is
An infinite number of charges each numerically equal to q and of the same sign are placed along the $x-$ axis at $x = 1,2,4,8.... \,metres$. Then the electric potential at $x = 0$ due to this set of charges is