In a chamber, a uniform magnetic field of 6.5 G ($1 ext{ G} = 10^{-4} ext{ T}$) is maintained. An

Question

In a chamber, a uniform magnetic field of 6.5 G ($1	ext{ G} = 10^{-4}	ext{ T}$) is maintained. An electron is shot into the field with a speed of $4.8 	imes 10^6	ext{ m/s}$ normal to the field.  What is the frequency of revolution of the electron in the above circular orbit? ($e = 1.6 	imes 10^{-19}	ext{ C}$, $m_e = 9.1 	imes 10^{-31}	ext{ kg}$)

Professor PC Thomas Classes · Answer

Frequency $
u = \frac{eB}{2\pi m} = \frac{1.6 	imes 10^{-19} 	imes 6.5 	imes 10^{-4}}{2 	imes 3.14 	imes 9.1 	imes 10^{-31}} \approx 18.18	ext{ MHz} \approx 18	ext{ MHz}$.