Discussion:
Thomson's Experiment and Charge to Mass Ratio
Q: Thomson's Experiment: Instead of turning off the electric field to determine the charge-to mass ratio, Thomson proceeded to switch off the magnetic field. Suppose that the electric field is pointed towards the y-axis. Then, as the electron travels along the x-axis and hits the glass tube located say, L distance away from the source, the electrons will be deflected along y-axis by a distance, say D. By measuring D, from the knowledge of E,v, and L, Thomson could deduce an expression for e/me. Can you do the same?