Problem 6: What is the time period of an electron projected into a uniform magnetic field of 10 mT and moves in a circle of radius 6 cm?

Solution

The time period of a charged particle moving in a circular path in a magnetic field can be calculated as

We know that mass of the electron, m = 9.11 × 10-31 kg and charge on electron is 1.6 × 10-19 C. Also, given that, magnetic field, B = 10 mT = 10 × 10-3 T and radius of the circular path of electron in the field = r = 6 cm = 0.06 m
Put the values