Question

A proton and an electron travelling along parallel paths enter a region of uniform magnetic field, acting perpendicular to their paths. Which of them will move in a circular path with higher frequency?

Answer 1

Radius of the orbit is given as r = `(mv)/(BQ)`

Time period = `(2pir)/v = (2pimv)/(vBQ) = (2pim)/(BQ)`

Frequency = `1/"Time period" = (BQ)/(2pim)`

As the frequency is inversely proportional to the mass of the particle, thus frequency of revolution of the electron is greater than that of proton because of less mass of electron.