A particle of mass m and charge `+q` approaches from a very large distance towards a uniformly charged ring ofradius Rand charge, mass same as that of particle, with initial velocity `v_(0)` along the axis of the ring as shown in the figure-1.420. What is the closest distance of approach between the ring and the particle? Assume the space to be gravity free and frictionless :

Options

A. ` sqrt ( ( q ^4 ) /( pi ^2 epsi _ 0 ^ 2 m ^2 v _ 0 ^ 4 ) - R^ 2 ) `
B. ` sqrt ( ( 3q ^ 4 )/ ( 2pi ^ 2 epsi _ 0 ^ 2 m ^2 v _ 0 ^4 ) + R^ 2 ) `
C. ` sqrt ( ( m ^ 2 v _0 ^ 4 ) /( pi^ 2 q ^ 4 epsi _0 ^ 2 ) - R^ 2 ) `
D. ` sqrt (( q ^ 4 )/( 2pi ^ 2 epsi _ 0 ^ 2 m ^ 2 v _ 0 ^ 4 ) - R^ 2 ) `

Answer

A