Question

In the Bohr model of hydrogen atom, the electron is pictured to rotate in a circular orbit of radius $5\times {10}^{-11}m$, at a speed $2.2\times {10}^6$. What is the current associated with electron motion in mA?

Answer 1

Speed = $2.2\times {10}^6$

radius = $5\times {10}^{-11}m$

time taken $=\frac{2\pi r}{speed}$

$=\frac{2\times \pi \times 5\times {10}^{-11}}{2.2\times {10}^6}=\frac{2\times 22\times 10\times 5\times {10}^{-11}}{7\times 22\times {10}^6}=\frac{10}{7}\times {10}^{-16}$

Current $\frac{q}{t}(1e=1.6\times {10}^{-19}C)$

$=\frac{1.6\times {10}^{-19}}{10\times {10}^{-16}}\times 7=\frac{1.6}{100}\times {10}^{-3}\times 7=112\times {10}^{-5}A=112\times {10}^{-5}\times 1000mA=1.12mA$