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
$\frac{1}{{4\pi {\varepsilon _0}}}.\frac{{{Q_1} + {Q_2}}}{r}$
$\frac{1}{{4\pi {\varepsilon _0}}}.\left( {\frac{{{Q_1}}}{r} + \frac{{{Q_2}}}{{{R_2}}}} \right)$
$\frac{1}{{4\pi {\varepsilon _0}}}.\left( {\frac{{{Q_1}}}{{{R_1}}} + \frac{{{Q_2}}}{{{R_2}}}} \right)$
$\frac{1}{{4\pi {\varepsilon _0}}}.\left( {\frac{{{Q_1}}}{{{R_1}}} + \frac{{{Q_2}}}{r}} \right)$
The electric potential at the surface of an atomic nucleus $(Z = 50)$ of radius $9.0×{10^{ - 13}}\, cm$ is
At distance of $5$ $cm$ and $10$ $cm $ outwards from the surface of a uniformly charged solid sphere, the potentials are $100$ $V$ and $75$ $V$ respectively . Then
Six point charges are placed at the vertices of a regular hexagon of side $a$ as shown. If $E$ represents electric field and $V$ represents electric potential at $O$, then
A conducting sphere of radius $R$ is given a charge $Q$. The electric potential and the electric field at the centre of the sphere respectively are
Consider two conducting spheres of radii ${{\rm{R}}_1}$ and ${{\rm{R}}_2}$ with $\left( {{{\rm{R}}_1} > {{\rm{R}}_2}} \right)$. If the two are at the same potential, the larger sphere has more charge than the smaller sphere. State whether the charge density of the smaller sphere is more or less than that of the larger one.