Question
An isolated conducting sphere of radius r has given charge q then PE??
ans is q2/8πe0r
But Sir ,why the ans q2/2πe0r is incorrect??
Joshi sir comment
let we have given x charge and want to give dx also to the sphere
so dE = [1/4πε0]xdx/r
now integrate and take limits of x as 0 to q