Question

Ratio of radii of second and first Bohr orbits of $H$ atom is:

• A. 2
• B. 4
• C. 3
• D. 5

Answer 1

Answer: (B)

According to Bohr rule, $r\propto n^2$
where $r$ is radii and $n$ is the number of orbit
So, $\frac{r_1}{r_2}=\frac{(2{)}^2}{(1{)}^2}=4$
Hence, ratio of radii is $4$