What is IP rating of a motor? What is insulation resistance of motor winding? Working principle of DC motor, DC generator, AC motor and AC alternator? What is Synchronization? What are SCR, AVR, DIAC, TRIAC, and IGBT? Can induction motor run in synchronous speed? What is megger and its application? Working principle of Induction motor? Advantage of back emf in Motor? What is armature reaction? What do we need for self-excitation of DC generator? What is d/ce b/n motor and generator? What is battery capacity? What is opto coupler?