A small conducting sphere of radius $r$ is lying concentrically inside a bigger hollow conducting sphere of radius $R.$ The bigger and smaller spheres are charged with $Q$ and $q (Q > q)$ and are insulated from each other. The potential difference between the spheres will be
$\frac{1}{{4\pi { \in _0}}}\left( {\frac{q}{r} - \frac{Q}{R}} \right)$
$\frac{1}{{4\pi { \in _0}}}\left( {\frac{Q}{R} + \frac{q}{r}} \right)$
$\frac{1}{{4\pi { \in _0}}}\left( {\frac{q}{r} - \frac{q}{R}} \right)$
$\frac{1}{{4\pi { \in _0}}}\left( {\frac{q}{R} - \frac{Q}{r}} \right)$
$1000$ small water drops each of radius $r$ and charge $q$ coalesce together to form one spherical drop. The potential of the big drop is larger than that of the smaller drop by a factor of
A point charge of magnitude $+ 1\,\mu C$ is fixed at $(0, 0, 0) $. An isolated uncharged spherical conductor, is fixed with its center at $(4, 0, 0).$ The potential and the induced electric field at the centre of the sphere is
An electric charge $10^{-3}\ \mu C$ is placed at the origin $(0, 0)$ of $X-Y$ coordinate system. Two points $A$ and $B$ are situated at $(\sqrt 2 ,\sqrt 2 )$ and $(2, 0)$ respectively. The potential difference between the points $A$ and $B$ will be......$V$
Consider a finite insulated, uncharged conductor placed near a finite positively charged conductor. The uncharged body must have a potential
Draw a graph for variation of potential $\mathrm{V}$ with distance $\mathrm{r}$ for a point charge $\mathrm{Q}$.