The radius of `1^(st)` Bohr's orbit for hydrogen atom is 'r'. The radius of second Bohr's orbit is

Options

A. 4r
B. `r^(3)`
C. `4r^(2)`
D. `r^(1//3)`

Answer

A

Explanation

`r_(n) = r_(1) xx n^(2)" "`(for hydrogen atom)
`r_(n) = r xx n^92)`
as `r_(1) = r` (given)
`r_(2) = r xx 2^(2)` (n=2, for second Bohr. orbit )
= 4r