The diagram shows a small bead of mass m carrying charge q. The bead can freely ring placed on a smooth fixed ring placed on a smooth horizontal plane. In the same plane a charge `+Q` has also been fixed as shown. The potential at the point P due to `+Q` is V. The velocity with which the bead should projected from the point P so that is can complete a circle should be greater than

Options

A. `sqrt((6qV)/m)`
B. `sqrt((qV)/m)`
C. `sqrt((3qV)/m)`
D. None of these

Answer

A

Explanation

`V_p=(KQ)/(4a)=V`
COE `q((KQ)/a)+0=q ((KQ)/(4a))+1/2 mv^2, 3q ((KQ)/(4a0))=1/2 mv^2 implies V=sqrt((6qv)/m)`