Physics - Modern Physics Question with Solution | TestHub

Radius of Bohr orbit is given by

$r_n =$$\left(\frac{{\epsilon }_0{h}^2}{\pi m{e}^2}\right)n^2$

The quantities in the bracket are constant

$\therefore r_n\propto n^2$

The expression gives the radius of the$n^{th}$Bohr orbit

$\frac{r_1}{r_2}= \frac{n_1^2}{n_2^2}$

$\frac{a}{r_2}= \frac{1}{3^2}$

$r_2= 9a$