A positive charge .Q. is fixed at a point, A negatively charged of mass .m. and charge .q. is revolving in a circular path of radius radius `r_(1)` with .Q. as the centre. The change in potential energy to change the radius of the circular path from `r_(1) and r_(2)` in joule is

Options

A. zero
B. `(1)/( 24 pi in 0) Qq [(1)/(r_1)-(1)/(r_1)]`
C. `(1)/(pi) Qq [(1)/(r_1) -(1)/(r_2)]`
D. `(Qq)/( 4 pi) [(1)/(r_2)-(1)/( r_1)]`

Answer

B