The electron in a hydrogen atom jumps from ground state to the higher energy state where its velcoity is reduced to one-third its initial value. If the radius of the orbit in the ground state is `r` the radius of new orbit will be

Options

A. `3 r`
B. `9r`
C. `(r )/(3)`
D. `(r )/(9)`

Answer

B

Explanation

`v = (1)/(137)(c )/(n)` or `prop(1)/(n)`
Since `v` is reduced to one-third therefore
`n = 3`
Now, `r prop n^(2)`.