Induction Motor MCQ [Questions with Answers]

Induction motor is one of the most popular motors in the electric industry. In an induction motor, the rotor voltage is induced rather than physically connecting the wires. Given below are the most important Induction Motor MCQ you should know.

Starters are used in induction motor

Starters are used in induction motor:

  1. To reduce torque
  2. When light loads are connected
  3. To reduce staring current
  4. To obtain high starting torque

Correct answer: 3. To reduce staring current


The slip of induction motor at no load is

The slip of induction motor at no load is:

  1. 0.2
  2. 0.05
  3. 0.03
  4. Less than 1%

Correct answer: 4. Less than 1%


If induction motor turns at synchronous speed, the induced voltage is

If induction motor turns at synchronous speed, the induced voltage is:

  1. Maximum
  2. Zero
  3. Halved
  4. Doubled

Correct answer: 2. Zero


The synchronous speed of a 220 V, 4 pole, 1 hp, 50 Hz induction motor is

The synchronous speed of a 220 V, 4 pole, 1 hp, 50 Hz induction motor is:

  1. 750
  2. 1500
  3. 3000
  4. 6000

Correct answer: 2. 1500


Induction motor is a

Induction motor is a:

  1. Singly excited machine
  2. Doubly excited machine
  3. Triple excited machine
  4. Quad excited machine

Correct answer: 1. Singly excited machine


The rotor windings are skewed to

The rotor windings are skewed to:

  1. Increase torque
  2. Reduce torque
  3. Eliminate harmonics
  4. None of these

Correct answer: 3. Eliminate harmonics


The rotor speed of induction motor is always ________ synchronous speed

The rotor speed of induction motor is always ___________ synchronous speed:

  1. Smaller than
  2. Greater than
  3. Equal to
  4. None of these

Correct answer: 1. Smaller than


The relationship between rotor slip, synchronous speed and rotor speed is

The relationship between rotor slip, synchronous speed and rotor speed is:

  1. (1-slip) * Rotor speed = Sync speed
  2. (1-slip) * Sync speed = Rotor Speed
  3. (1-slip) * (1-slip) = Sync speed * Rotor Speed
  4. Rotor Speed + Sync speed = 1-slip

Correct answer: 2. (1-slip) * Sync speed = Rotor Speed


The induced torque in the absence of rotors magnetic field is

The induced torque in the absence of rotors magnetic field is:

  1. Maximum
  2. Zero
  3. Halved
  4. Doubled

Correct answer: 2. Zero


If rotor of the induction motor is driven faster than synchronous speed

If rotor of the induction motor is driven faster than synchronous speed:

  1. Induced torque reverses direction
  2. Motor becomes a generator
  3. Both of these
  4. None of these

Correct answer: 3. Both of these

Which one of following is the correct relationship between rotor current in three phase induction motor and slip

Which one of following is the correct relationship between rotor current in three phase induction motor and slip

  1. Rotor current is directly proportional to slip
  2. Rotor current is inversely proportional to slip
  3. Rotor current is independent of slip

Correct answer: 1. Rotor current is directly proportional to slip

More MCQ on Induction Motors

  1. The Correct Statement about DC field current in Induction Motor
  2. The Induction Motor Runs at the Speed
  3. The Correct Relationship between Slip, Synchronous, and Rotor speed of Induction Motor
  4. Formula for Synchronous Speed of Induction Machine
  5. Five
  6. The synchronous speed of 4 pole, 50 Hz induction Motor is
  7. A 4 pole, 60 Hz Induction Motor Has a Slip of 5%. The Speed of motor is
  8. A 4 pole, 50 Hz Induction Motor Has a Slip of 5%. The Speed of motor is
  9. Size of Single Phase Induction Motor vs Three Phase Induction Motor for Same Ratings
  10. Usually, a Single Phase Induction Motor has number of poles
  11. The rotor frequency of a 4 pole, 60 Hz induction motor having full load slip of 5% at rated load is
  12. If rotor of Induction motor is rotating at synchronous speed the torque will be
  13. What is No-load slip value in induction motor
  14. The current in the starting winding of capacitor-start single-phase motors has what relationship with voltage [49]
  15. What will happen to a single-phase motor when its capacitor is short-circuited
  16. With reference to a capacitor-start and run motor the function of the running capacitor in series with the auxiliary winding is
  17. WREF capacitor-start motor the phase displacement between starting and running winding can be nearly
  18. In a split-phase induction motor which winding is connected through centrifugal switch
  19. The torque developed by a single-phase induction motor at starting is [54]
  20. The motor which will give relatively high starting torque
  21. Which type of capacitor is preferred for utilization in capacitor-start and run motor
  22. Which one of the following motors will have comparatively higher power factor
  23. In a universal motor the width of the brush is nearly
  24. The single-phase motor which is reversible
  25. Which one of the following is practical application of shaded pole motors
  26. The motor which has the highest power to weight ratio
  27. By shifting the position of brushes in repulsion motor which parameter can be controlled [Speed/Direction]
  28. The centrifugal switch is used to disconnect starting winding at which instant
  29. Shaded-pole motors have percentage efficiency of ranges
  30. The revolving field in a shaded-pole single-phase induction motor is produced by using
  31. The shading coil in a shaded-pole induction motor usually consists of
  32. For which of the applications a reluctance motor is preferred
  33. Which type of induction motor is recommended for high speed and high starting torque applications
  34. A hysteresis motor works on the principle of
  35. Which of the following motor will provide the highest starting torque
  36. Rotor slots are skewed in induction motor so as to

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