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

Options

A. zero
B. `(Qq)/(4pi in_(0))((1)/(r_(1))-(1)/(r_(2)))`
C. `(Qq)/(pi)((1)/(r_(1))-(1)/(r_(2)))`
D. `(Qq)/(4pi)((1)/(r_(2))-(1)/(r_(1)))`

Answer

B

Explanation

`DeltaU=U_(2)-U_(1)`