Moving Charges and Magnetism Problems - Numerical 12

12.

An electron is projected with a speed of 10⁵ms^-1 at right angles to a magnetic field of 0.019 G. Calculate the radius of the circle described by the electron.

Suggested solution:

Let R be the radius of the circular path described by the electron.

Then mv²/R = B e v or R = mv/B e.

Given: B = 0.019; G = 0.019 x 10^-4; T = 1.9 x 10^-6 T

Therefore, R = 9.1 x 10^-31 x 10⁵/1.9 x 10^-6 x 1.6 x 10^-19

= 0.299m