A thin spherical conducting shell of radius $R$ has a charge $q$ . Another charge $Q$ is placed at the centre of the shell. The electrostatic potential at a point $P$ at a distance $R/2$ from the centre of the shell is
$\frac{{2Q}}{{4\pi { \in _0}R}}$
$\frac{{2Q}}{{4\pi { \in _0}R}} - \frac{{2q}}{{4\pi { \in _0}R}}$
$\frac{{2Q}}{{4\pi { \in _0}R}} + \frac{q}{{4\pi { \in _0}R}}$
$\frac{{(q + Q)}}{{4\pi { \in _0}R}}\frac{2}{R}$
Twenty seven drops of water of the same size are equally and similarly charged. They are then united to form a bigger drop. By what factor will the electrical potential changes.........$times$
Considering a group of positive charges, which of the following statements is correct?
Derive an expression for the electric potential in a electric field of positive point charge at distance $\mathrm{r}$.
Figure shows the variation of electric field intensity $E$ versus distance $x$. What is the potential difference between the points at $x=2 \,m$ and at $x=6 \,m$ from $O$ is ............. $V$
Write an equation for an electrostatic potential of a negative point charge.