Question

In an atom electrons revolves around the nucleus along a path of radius $0.72 \,\mathring{A}$ making $9.4 \times 10^{18}$ revolution per second. The equivalent current is $(e = 1.6 \times 10^{-19}\, C)$

• A. $1.2\,A$
• B. $1.5\,A$
• C. $1.4\,A$
• D. $1.8\,A$

Answer 1

Answer: (B)

Radius of electron orbit $r=0.72\,\mathring{A}=0.72 \times 10^{-10}\,m$
Frequency of revolution of electron in orbit of given atom $\upsilon=9.4 \times 10^{18}$ rev/$s$
(where $T$ is time period of revolution of electron in orbit)
$\therefore $ Then equivalent current is
$I=\frac{e}{T}=e\upsilon=1.6 \times 10^{-19} \times 9.4 \times 10^{18}$
$=1.504\,A$