Question

The time taken by the electron in one complete revolution in the $n ^{\text {th }}$ Bohr's orbit of the hydrogen atom is

• A. Inversely proportional to $n^{2}$
• B. Directly proportional to $n ^{3}$
• C. Directly proportional to $\frac{ h }{2 \pi}$
• D. Inversely proportional to $\frac{n}{h}$

Answer 1

Answer: (B)

Time period $=\frac{\text { circumference }}{\text { velocity }}=\frac{2 \pi r}{v_{n}}$
$=\frac{n^{3}}{z^{2}} \times 1.5 \times 10^{-16}$ seconds
Time period $\propto n ^{3}$