Question

In the hydrogen atom, the electron is making $6.6 \times 10^{15}$ rps. If the radius of orbit is $0.53 \times 10^{-10}$ m, then magnetic field produced at the centre of the orbit is

• A. 140T
• B. 12.5T
• C. 1.4T
• D. 0.14T

Answer 1

Answer: (B)

12.5T

Answer 2

Current, $i=q v$
$B=\frac{\mu_{0} i}{2 r}=\frac{\mu_{0} q v}{2 r}$
$=\frac{4 \pi \times 10^{-7} \times 1.6 \times 10^{-19} \times 6.6 \times 10^{15}}{2 \times 0.53 \times 10^{-10}}$
$=\frac{2 \pi \times 1.6 \times 6.6}{5.3}=12.513\, T$