Answer to Question #300918 in Electricity and Magnetism for aisme

Question

An electron is accelerated through a 100 V potential difference before perpendicularly entering a uniform magnetic field. Inside the field, the electron moves in circular trajectory of radius 4 cm, calculate the magnetic force that acts on the electron.

Answer 1

$B=\frac{mv}{eR},$

$v=\sqrt{\frac{2eU}m},$

$B=\sqrt{\frac{2mU}{eR^2}}=5.2~mT.$