Point charge ${q_1} = 2\,\mu C$ and ${q_2} = - 1\,\mu C$ are kept at points $x = 0$ and $x = 6$ respectively. Electrical potential will be zero at points

A neutral spherical copper particle has a radius of $10 \,nm \left(1 \,nm =10^{-9} \,m \right)$. It gets charged by applying the voltage slowly adding one electron at a time. Then, the graph of the total charge on the particle versus the applied voltage would look like

A hollow metal sphere of radius $5\, cm$ is charged so that the potential on its surface is $10\, V$. The potential at the centre of the sphere is

Ten charges are placed on the circumference of a circle of radius $R$ with constant angular separation between successive charges. Alternate charges $1,3,5,7,9$ have charge $(+q)$ each, while $2,4,6,8,10$ have charge $(-q)$ each. The potential $V$ and the electric field $E$ at the centre of the circle are respectively

(Take $V =0$ at infinity $)$

A charge of ${10^{ - 9}}\,C$ is placed on each of the $64$ identical drops of radius $2\,cm$. They are then combined to form a bigger drop. Find its potential

$64$ identical drops each charged upto potential of $10\,mV$ are combined to form a bigger dorp. The potential of the bigger drop will be $..........\,mV$