Review questions dealing with magnetic fields and electric currents... The effect of a magnetic field on a moving charge was demonstrated on video using a cathode ray tube, phosphorous screen, and magnetic field. The deflection was shown as occurring when the electron passed through the field at an angle, but not parallel. The deflection was always 90 degrees. The effect on a wire with a current was also depicted, along with the right hand rule to determine the direction of the field and the left hand rule to show the direction of movement. The Earth as a magnet was discussed in terms of the magnetic field protecting against radiation coming from space.