FAULTS, THEIR CAUSES AND REMEDIES OF A.C. 3 PHASE MOTOR MCQs – CHAPTER 3 DAE 10 min Score: 0 Attempted: 0/10 Subscribe 1. Number of slip rings in squirrel cage motor is: (A) Zero (B) 3 (C) 2 (D) 4Show All Answers 2. Starting torque of squirrel cage induction motor is: (A) Very high (B) Low (C) Zero (D) HighShow All Answers 3. Resistance of the stator of 3-phase motor should not be less than: (A) 1000 Ohm (B) 1 M Ohm (C) 10k Ohm (D) 2 M OhmShow All Answers 4. A 3-phase wound motor does not run; its cause may be: (A) Open circuit in field (B) Loose bearing (C) Low load (D) None of theseShow All Answers 5. Which of the following is a mechanical fault in 3-phase synchronous motor: (A) Punctured the insulation (B) Breaking the motor fan (C) Burning slip rings (D) Open circuitShow All Answers 6. Wound rotor motor can be run on: (A) None of these (B) D.C supply only (C) Both A.C & D.C (D) A.C supply onlyShow All Answers 7. Stator of 3-phase synchronous motor is too hot; possible causes: (A) Overload (B) Both a & b (C) Low excitation (D) None of theseShow All Answers 8. If wrong connection for a given voltage, then motor will be: (A) Overheated (B) Noise on no load (C) Both a & b (D) None of theseShow All Answers 9. Wound rotor motor runs at half speed; possible causes: (A) Short circuit (B) No load (C) Open circuit in rotor connection (D) Earth faultShow All Answers 10. Failure of bearing is: (A) Mechanical fault (B) Magnetic fault (C) Earth fault (D) Electrical faultShow All Answers
