Question

In a hydrogen atom, an electron revolves around the nucleus in an orbit of radius $r$ with velocity $v$, the current corresponding to the revolving electron is

• A. $I=\frac{e r}{2 \pi v}$
• B. $I=\frac{e v}{2 \pi}$
• C. $I=\frac{e v}{2 \pi r}$
• D. $I=\frac{e v}{\pi r}$

Answer 1

Answer: (C)

$T$ is the time period of revolution.
Let $r$ be the orbital radius of the electron, and $v$ the orbital speed. Then,
$T=\frac{2 \pi r}{v}, I=\frac{2}{T}$
On substituting, we have $I=e v / 2 \pi r$.