In a hypothetivsl system, a particle of mass m and charge -3q is moving around a very heavy particle having charge q. Assuming Bohr's model to be true ot this system the orbital velocity of mass m when it is nearest to heavy particle is

Options

A. `(3 q^(2))/(2 epsilon_(0) h)`
B. `(3 q^(2))/(4 epsilon_(0) h)`
C. `(3 q)/(2 pi epsilon_(0) h)`
D. `(3 q^(2))/(4 pi epsilon_(0) h)`

Answer

A

Explanation

`(mv^(2))/( r) = (3 q^(3))/(4 pi epsilon_(0) r^(2)) implies m v r = (3 q^(2))/(4 pi epsilon_(0) v)` (i)
and `(nh)/(2 pi) = m v r` (ii)
Using Bohr's (i) and (ii) and putting `n = 1`
`(h)/(2 pi) = (3 q^(2))/(4 pi epsilon_(0) v) implies v = (3 q^(2))/(2 pi epsilon_(0) h)`