Question

The ratio of the velocity of light and the velocity of electron in the first orbit of a hydrogen atom. [Given $h = 6.624 \times 10^{-27}$ erg-sec; m = $9.108 \times 10^{-28}$ $g,r = 0.529 \times 10^{-8}\, cm$.]

• A. $137$
• B. $\frac{1}{137}$
• C. $\frac{1}{13700}$
• D. $13700$

Answer 1

Answer: (A)

$v=\frac{h}{2\pi m}$
$ =\frac{6.624 \times10^{-27}}{2\times3.14\times9.108\times10^{-28}\times0.529\times10^{-8}} $
$=2.189 \times10^{8} $
$\frac{e}{v}=\frac{3\times10^{8}}{2.189\times10^{8}}=137$