Magnetic material, reluctance, magnetic circuit, inductance, energy storage in magnetic field, energy and co-energy, electromagnetic force, electromagnetic torque, core loss, structure and basic theory of transformer, ideal transformer, equivalent circuit of transformer, three-phase transformer, auto transformer, structure and basic theory of dc machines, armature induced emf, electromagnetic torque, armature windings of DC machines, equivalent circuit of DC generator, equivalent circuit of DC motor, performance of DC machines, armature reaction, inter-pole and compensating winding, DC motor speed control, DC motor protection