Moving Charges And Magnetism

Two electrons, \(e_1\) and \(e_2\) of mass \(m\) and charge \(q\) are injected into the perpendicular direction of the magnetic field \(B\) such that the kinetic energy of \(e_1\) is double than that of \(e_2\). The relation of their frequencies of rotation, \(f_1\) and \(f_2\) is