EEE Unit-1 DC Machines MCQ's MULTIPLE CHOICE QUESTIONS ON UNIT 1: DC MACHINES Edit 1.The sole purpose of a Commutator in a dc generator is to------- ((A))increase output voltage ((B)) reduce sparking at brushes ((C)) provide smoother output ((D)) convert the induced ac into dc Hide ! Answer : D 2.In a dc generator, the generated emf is directly proportional to the------ ((A)) field current ((B)) pole flux ((C)) number of armature parallel paths ((D)) number of dummy coils Hide ! Answer:B 3.An ideal dc generator has .......... voltage regulation. ((A))low ((B))zero ((C))positive ((D))negative Hide ! Answer:B 4.Which generator may have poorest voltage regulation? ((A))series ((B))shunt((C))compound ((D))high Hide ! Answer:A 5.Voltage equation of a dc motor is----- ((A)) V = Eb + IaRa ((B)) Eb = V + IaRa ((C))V = Eb /IaRa ((D))V = Eb + Ia2Ra Hide ! Answer: A 6.Which of the following motor has the constant speed? ((A))Series motor ((B))Shunt motor ((C))Cumulatively compound motor ((D)