The variation of electrostatic potential $V$ with radial distance $r$ from the centre of a positively charged metallic thin shell of radius $R$ is given by the graph:

There is a uniformly charged non-conducting solid sphere made of material of dielectric constant $1$. If the electric potential at infinity is zero,then the potential at its surface is $V$. If we take the electric potential at its surface to be zero,then the potential at the centre will be

The electrostatic potential energy of the given system of charges placed at the corners of a square of side $a$ is:

$90 \ J$ of work is done to move an electric charge of magnitude $3 \ C$ from a place $A$,where potential is $-10 \ V$,to another place $B$,where potential is $V_1 \ V$. The value of $V_1$ is: (in $V$)

An electron (charge = $1.6 \times 10^{-19} \text{ C}$) is accelerated through a potential difference of $1,00,000 \text{ V}$. The energy acquired by the electron is:

Three identical charges of $10 \ \mu C$ are placed at the vertices of an equilateral triangle of side $10 \ cm$. The electrostatic potential energy of the system is ....... $J$.