Q. The radius of the orbital of electron in the hydrogen atom is $0.5\ \mathring{\mathrm{A}}.$ The speed of the electron is $2 \times 10^{6}\ m/s.$ Then the current in the loop due to the motion of the electron is
A) $1\ mA$
B) $1.5\ mA$
C) $2.5\ mA$
D) $1.5 \times 10^{- 2}\ mA$
Explanation
(a) Time period of revolution of electron $T = \frac{2\pi}{\omega} = \frac{2\pi r}{v}$
Hence corresponding electric current $i = \frac{e}{T} = \frac{ev}{2\pi r}$
$\Rightarrow i = \frac{1.6 \times 10^{- 19} \times 2 \times 10^{6}}{2 \times 3.14 \times 0.5 \times 10^{- 10}} = 1mA$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.