Question

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

• A. $2$
• B. $4$
• C. $3$
• D. $5$

Answer 1

Answer: (B)

$4$

Since radius is directly proportional to the square of 'n',
$\frac{\text{radius of}{2}^{nd}\text{Bohr orbit}}{\text{radius of}{1}^{st}\text{Bohr orbit}}=\frac{0.529}{0.529}\times \frac{2^2}{1}=4$