Magnetism and Moving charges *Oersted had showed in the 19th century that a current carrying conductor was surrounded by a magnetic field *Moving charges experience a force in a magnetic field Factors that effect the magnitude of force *F = ILBsinƒÖ Van Allen Radiation belts - example pf motion of charged particles in a field *Charged particles trapped inside the earth's magnetic field, which oscillate back and forth between the poles *These charged particles …showed first 75 words of 2146 total…

…showed last 75 words of 2146 total…- to vary below 50 Hertz, a change in frequency is needed Principle of AC induction motor *Changing magnetic field in electromagnet induces current in rods of squirrel cage *Current in rod, generate their own magnetic fields - oppose magnetic field of electromagnet *Repulsion of magnetic fields cause the cage to rotate - repeated 100 time a second Why the majority of motors are AC induction motors *Cheap *Simple in design *Less moving parts - low maintenance