Sail E0 Webinar

MCQs

Total Questions : 395 | Page 9 of 40 pages
Question 81. While starting a salient pole synchronous motor by induction motor action and connecting field discharge resistance across field, starting and accelerting torque is produced by
  1.    induction motor torque in field winding
  2.    induction motor torque in damper winding
  3.    eddy current and hysteresis torque in pole faces
  4.    reHetance motor torque due to saliency of the rotor
  5.    all of the above methods
 Discuss Question
Answer: Option E. -> all of the above methods
Question 82. If one-phase of a 3-phase synchronous motor is short-circuited, motor
  1.    will refuse to start
  2.    will overheat in spots
  3.    will not come upto speed
  4.    will fail to pull into step
 Discuss Question
Answer: Option A. -> will refuse to start
Question 83. The net armature voltage of a synchronous motor is equal to the
  1.    vector sum of Eb and V
  2.    arithmetic sum of Eb and V
  3.    arithmetic difference of Eb and V
  4.    vector difference of Eh and V
 Discuss Question
Answer: Option D. -> vector difference of Eh and V
Question 84. The back e.m.f. of a synchronous motor depends on
  1.    speed
  2.    load
  3.    load angle
  4.    all of the above
 Discuss Question
Answer: Option C. -> load angle
Question 85. The back e.m.f. in the stator of a synchronous motor depends on
  1.    number of poles
  2.    flux density
  3.    rotor speed
  4.    rotor excitation
 Discuss Question
Answer: Option D. -> rotor excitation
Question 86. The shaft of synchronous motor is made of
  1.    mild steel
  2.    chrome steel
  3.    alnico
  4.    stainless steel
 Discuss Question
Answer: Option A. -> mild steel
Question 87. A synchronous motor can develop synchronous torque
  1.    when under loaded
  2.    while over-excited
  3.    only at synchronous speed
  4.    below or above synchronous speed
 Discuss Question
Answer: Option C. -> only at synchronous speed
Question 88. The induced e.m.f. in a synchronous motor working on leading power factor will be
  1.    more than the supply voltage
  2.    less than the supply voltage
  3.    equal to the supply voltage
  4.    none of the above
 Discuss Question
Answer: Option A. -> more than the supply voltage
Question 89. When the field of a synchronous motor is under-excited, the power factor will be
  1.    leading
  2.    lagging
  3.    unity
  4.    zero
 Discuss Question
Answer: Option B. -> lagging
Question 90. If the field of a synchronous motor is underexcited, the power factor will be
  1.    zero
  2.    unity
  3.    lagging
  4.    leading
 Discuss Question
Answer: Option C. -> lagging

Latest Videos
Chapter 1 - GLOBAL STEEL SCENARIO & INDIAN STEEL INDUSTRY Part 1 : (13-04-2024) INDUSTRY AND COMPANY AWARENESS (ICA)
Direction Sense Test Part 1 Reasoning (Hindi)
Chapter 1 - RMHP / OHP / OB & BP Part 1 : (14-02-2024) GPOE
Cube & Cuboid Part 1 Reasoning (Hindi)
Data Interpretation (DI) Basic Concept Reasoning (Hindi)
Counting Figures Part 1 Counting Of Straight Lines Reasoning (Hindi)
Sail E0 free webinar Webinars
Real Numbers Part 7 Class 10 Maths
Real Numbers Part 1 Class 10 Maths
Polynomials Part 1 Class 10 Maths

Latest Test Papers

GPOE / GPA Combined 1 Free Mock Test SAIL JO E-0 2024
Chapter 3.1 : INTRODUCTION Chapter 3 : Sinter Plant SAIL E0 - GPOE/GPA 2024
Chapter 2.3 : COAL HANDLING PLANT - Set 1 Chapter 2 : Coke Ovens and Coal Chemicals SAIL E0 - GPOE/GPA 2024
Chapter 1.1 : INTRODUCTION Chapter 1 : Raw Material Handling Plant SAIL E0 - GPOE/GPA 2024
DSP Combined 1 Free Revision Test SAIL JO E-0