The electric potential at the surface of a hollow metallic sphere is $10\, V$. What will be the electric potential at its center (in $, V$)?

Three particles,each having a charge of $10\,\mu C$,are placed at the corners of an equilateral triangle of side $10\,cm$. The electrostatic potential energy of the system is.....$J$ (Given $\frac{1}{4\pi\varepsilon_0} = 9 \times 10^9\,N\cdot m^2/C^2$).

Two point charges $-20 \,\mu C$ and $+40 \,\mu C$ are separated by a distance $r$. At which region$(s)$ will the electric potential be zero?

$A$ charge of $10^{-3} \ \mu C$ is placed at the origin $(0, 0)$ of an $X-Y$ coordinate system. Two points $A$ and $B$ are located at $(\sqrt{2}, \sqrt{2})$ and $(2, 0)$ respectively. The potential difference between points $A$ and $B$ is ....... $V$.

An electric point charge $10^{-3} \mu C$ is placed at the origin $(0, 0)$ of an $X-Y$ 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.....$volt$.

Four identical charges $+50\,\mu C$ each are placed,one at each corner of a square of side $2\,m$. How much external energy is required to bring another charge of $+50\,\mu C$ from infinity to the centre of the square? (Given $\frac{1}{4\pi\varepsilon_0} = 9 \times 10^9\,\frac{N\cdot m^2}{C^2}$)