The orbital electron of the hydrogen atom jumps from the ground state to a higher energy state and its orbital velocity is reduced to one third of its initial value. If the radius of the orbit in the ground state is r, then what is the radius of the new orbit ?

Options

A. 3R
B. 9R
C. 6R
D. 12R

Answer

B

Explanation

`v prop 1/n " and " R prop n^2 therefore R prop 1/v^2`
`R_2 prop (1)/((v//3)^2) i.e. 9/v^2`
`therefore R_2/R = 9/v^2 xx v^2/1 =9 therefore R_2 = 9R_1`