61. An induction motor can run at synchronous speed when A. It is run on load B. It is run in reverse direction C. It is run on voltage higher than the rated voltage D. e.m.f. is injected in the rotor circuit Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
62. Slip ring motor is preferred over squirrel cage induction motor where A. High starting torque is required B. Load torque is heavy C. Heavy pull out torque is required D. All of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
63. A change of 4% of supply voltage to an induction motor will produce a change of approximately A. 4% in the rotor torque B. 8% in the rotor torque C. 12% in the rotor torque D. 16% in the rotor torque Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
64. If an induction motor with certain ratio of rotor to stator slots, runs at $$\frac{1}{7}$$ of the normal speed, the phenomenon will be termed as A. Humming B. Hunting C. Crawling D. Cogging Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
65. The 'cogging' of an induction motor can be avoided by A. Proper ventilation B. Using DOL starter C. Autotransformer starter D. Having number of rotor slots more or less than the number of stator slots (not equal) Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
66. The power scale of circle diagram of an induction motor can be found from A. Stator resistance test B. No-load test only C. Short-circuit test only D. None of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option C No explanation is given for this question Let's Discuss on Board
67. In a three-phase induction motor, the number of poles in the rotor winding is always A. Zero B. More than the number of poles in stator C. Less than number of poles in stator D. Equal to number of poles in stator Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
68. Which type of bearing is provided in small induction motors to support the rotor shaft? A. Ball bearings B. Cast iron bearings C. Bush bearings D. None of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option A No explanation is given for this question Let's Discuss on Board
69. The vafcie of transformation ratio of an induction motor can be found by A. Open-circuit test only B. Short-circuit test only C. Stator resistance test D. None of the above Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option B No explanation is given for this question Let's Discuss on Board
70. An induction motor is identical to A. D.C. compound motor B. D.C. series motor C. Synchronous motor D. Asynchronous motor Answer & Solution Discuss in Board Save for Later Answer & Solution Answer: Option D No explanation is given for this question Let's Discuss on Board
