Halliday, Resnick & Walker — Magnetic Fields: Problem 45

45 A certain particle is sent into a uniform magnetic field, with the particle’s velocity vector perpendicular to the direction of the field. Figure 28-38 gives the period T of the particle’s motion versus the inverse of the field magnitude B. The vertical axis scale is set by \(T_s = 80.0 \text{ ns}\), and the horizontal axis scale is set by \(B_s^{-1} = 10.0 \text{ T}^{-1}\). What is the ratio \(m/q\) of the particle’s mass to the magnitude of its charge?