DIRECT CURRENT MOTORS; THEIR FAULTS CAUSES AND REMEDIES MCQs – CHAPTER 5 DAE 10 min Score: 0 Attempted: 0/10 Subscribe 1. No of slip rings in D.C motor is: (A) 3 (B) Zero (C) 4 (D) 2Show All Answers 2. Brushes of D.C motor are made of: (A) Hard carbon (B) Soft carbon (C) Carbon (D) AluminumShow All Answers 3. Armature reaction of an unsaturated D.C motor is: (A) Cross magnetizing (B) De magnetizing (C) Magnetizing (D) None of theseShow All Answers 4. The back e.m.f in a D.C motor: (A) Aids the applied voltage (B) Opposes the applied voltage (C) Aids the armature current (D) None of theseShow All Answers 5. The speed of D.C motor can be varied by varying: (A) All of these (B) Applied voltage (C) Resistance in series with armature (D) Field currentShow All Answers 6. When the speed of D.C motor increases, its armature current: (A) Increases (B) Remains constant (C) Decreases (D) None of theseShow All Answers 7. Types of D.C motor: (A) Series (B) Compound (C) All of these (D) ShuntShow All Answers 8. Motor runs backward, possible reasons: (A) Low voltage (B) Reverse connection (C) Both a & b (D) None of theseShow All Answers 9. D.C motor heats up during running: (A) All of these (B) Short circuit (C) Overload (D) Bearing jamShow All Answers 10. The speed of D.C motor is: (A) Always constant (B) Directly proportional to the flux (C) Directly proportional to back e.m.f (D) None of theseShow All Answers
