A particle of charge e and mass m moves with a velocity v in a magnetic field B applied perpendicular to the motion of the particle .The radius r of its path in the field is

Options

A. `(mv)/(Be)`
B. `(Be)/(mv)`
C. `(ev)/(Bm)`
D. `(Bv)/(em)`

Answer

A

Explanation

Magnetic force on a charged particle provides the necessary centripetal force for the circular motion of the charged particle.
`therefore (mv^(2))/(R )=qvB` or `r=(mv)/(qB)=(mv)/(eB)`