Question

In a hydrogen atom, an electron moves in an orbit of radius $5.0\times {10}^{-11}m$ with a speed of $2.2\times {10}^{6}m{s}^{-1}$. The equivalent current is :

• A. $11.2\times {10}^{-3}A$
• B. $1.9\times {10}^{-3}A$
• C. $1.12\times {10}^{-3}A$
• D. $11.2\times {10}^{4}A$

Answer 1

Answer: (C)

$1.12\times {10}^{-3}A$

Current $=$ Charge passing per unit time $q$

$I=\frac{q}{t}$

$t=\frac{2\pi r}{v}$

$I=\frac{q}{2\pi r}.v=\frac{1.6\times {10}^{19}\times 2.2\times {10}^6}{5\times {10}^{-11}\times 2n}$

$I=\frac{1.6\times 2.2}{5\times 2\pi }\times {10}^{-2}=1.12\times {10}^{-3}A$

$I=1.12mA$