Derive equation 2 for the e/m ratio apparatus. You will need to use conservation of energy, to find the velocity of the electron and Newton's 2nd Law for circular motion and combine them. Derive the equation for the radius of the electron trajectory inside the field, explains the factor that might affect the radius and how. For PHY2049 Use Ampere's or BiotSavart Laws and derive equation 1. Show that the magnetic field at the middle of the d separation between the two coils is uniform ( B = Constant ). To proof that the magnetic field is uniform: =0 x=dl2