Question

An electron is revolving around a proton in a circular orbit of radius $\frac{1}{2}{A}^{\circ }$. If it produces a magnetic field of 14 T, its angular velocity in rad/s

• A. $4\times {10}^{16}$
• B. $4\times {10}^{-15}$
• C. $4\times {10}^{17}$
• D. $4\times {10}^{18}$

Answer 1

The correct option is A $4\times {10}^{16}$

$B=\frac{{\mu }_{0}wq}{4\pi r};14=\frac{4\pi \times {10}^{-7}w\times 1.6\times {10}^{-19}}{4\pi \times \frac{1}{2}\times {10}^{-10}}=\frac{7}{1.6}\times {10}^{16}=4\times {10}^{16}rad{s}^{-1}$