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 distance $\frac{R}{2}$ from the centre of the shell is
$\frac{{(q + Q)}}{{4\pi {\varepsilon _0}}}\frac{2}{R}$
$\frac{{2Q}}{{4\pi {\varepsilon _0}R}}$
$\frac{{2Q}}{{4\pi {\varepsilon _0}R}} - \frac{{2q}}{{4\pi {\varepsilon _0}R}}$
$\frac{{2Q}}{{4\pi {\varepsilon _0}R}} + \frac{q}{{4\pi {\varepsilon _0}R}}$
Charges are placed on the vertices of a square as shown. Let $E$ be the electric field and $V$ the potential at the centre. If the charges on $A$ and $B$ are interchanged with those on $D$ and $C$ respectively, then
charge $Q$ is uniformly distributed over a long rod $AB$ of length $L$ as shown in the figure. The electric potential at the point $O$ lying at distance $L$ from the end $A$ is
In an hydrogen atom, the electron revolves around the nucleus in an orbit of radius $0.53 \times {10^{ - 10}}\,m$. Then the electrical potential produced by the nucleus at the position of the electron is......$V$
Two charges of magnitude $+ q$ and $-\,3q$ are placed $100\,cm$ apart. The distance from $+ q$ between the charges where the electrostatic potential is zero is.......$cm$
Four charges of $1\ \mu C, 2\ \mu C, 3\ \mu C,$ and $- 6\ \mu C$ are placed one at each corner of the square of side $1\,m$. The square lies in the $x-y$ plane with its centre at the origin.