In a hypothetical system , a partical of mass `m` and charge `-3 q` is moving around a very heavy partical chaRGE `q`. Assume that Bohr's model is applicable to this system , then velocuity of mass `m` in the first orbit is

Options

A. `(3q^2)/(2 epsi_0h)`
B. `(3q^2)/( 4 epsi_0h)`
C. `(3q)/(2 pi epsi_0h)`
D. `(3q )/(4 pi epsi_0 h)`

Answer

A

Explanation

`(mv^2)/( r ) = ( 3q^2)/( 4 pi epsi_0 r^2)implies mvr = ( 3q^2 )/(4 pi epsi_0 v ) `
` and ( nh )/( 2 pi ) = mvr`
using (I ) and (ii ) and putting n=1
`h/ (2 pi) = ( 3q^2)/( 4 pi epsi_0 v ) implies = (3q^2)/( 2 epsi_0 h)`