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:
- To reduce torque
- When light loads are connected
- To reduce staring current
- 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:
- 0.2
- 0.05
- 0.03
- 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:
- Maximum
- Zero
- Halved
- 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:
- 750
- 1500
- 3000
- 6000
Correct answer: 2. 1500
Induction motor is a
Induction motor is a:
- Singly excited machine
- Doubly excited machine
- Triple excited machine
- Quad excited machine
Correct answer: 1. Singly excited machine
The rotor windings are skewed to
The rotor windings are skewed to:
- Increase torque
- Reduce torque
- Eliminate harmonics
- 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:
- Smaller than
- Greater than
- Equal to
- 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-slip) * Rotor speed = Sync speed
- (1-slip) * Sync speed = Rotor Speed
- (1-slip) * (1-slip) = Sync speed * Rotor Speed
- 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:
- Maximum
- Zero
- Halved
- 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:
- Induced torque reverses direction
- Motor becomes a generator
- Both of these
- 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
- Rotor current is directly proportional to slip
- Rotor current is inversely proportional to slip
- Rotor current is independent of slip
Correct answer: 1. Rotor current is directly proportional to slip
More MCQ on Induction Motors
- The Correct Statement about DC field current in Induction Motor
- The Induction Motor Runs at the Speed
- The Correct Relationship between Slip, Synchronous, and Rotor speed of Induction Motor
- Formula for Synchronous Speed of Induction Machine
- Five
- The synchronous speed of 4 pole, 50 Hz induction Motor is
- A 4 pole, 60 Hz Induction Motor Has a Slip of 5%. The Speed of motor is
- A 4 pole, 50 Hz Induction Motor Has a Slip of 5%. The Speed of motor is
- Size of Single Phase Induction Motor vs Three Phase Induction Motor for Same Ratings
- Usually, a Single Phase Induction Motor has number of poles
- The rotor frequency of a 4 pole, 60 Hz induction motor having full load slip of 5% at rated load is
- If rotor of Induction motor is rotating at synchronous speed the torque will be
- What is No-load slip value in induction motor
- The current in the starting winding of capacitor-start single-phase motors has what relationship with voltage [49]
- What will happen to a single-phase motor when its capacitor is short-circuited
- With reference to a capacitor-start and run motor the function of the running capacitor in series with the auxiliary winding is
- WREF capacitor-start motor the phase displacement between starting and running winding can be nearly
- In a split-phase induction motor which winding is connected through centrifugal switch
- The torque developed by a single-phase induction motor at starting is [54]
- The motor which will give relatively high starting torque
- Which type of capacitor is preferred for utilization in capacitor-start and run motor
- Which one of the following motors will have comparatively higher power factor
- In a universal motor the width of the brush is nearly
- The single-phase motor which is reversible
- Which one of the following is practical application of shaded pole motors
- The motor which has the highest power to weight ratio
- By shifting the position of brushes in repulsion motor which parameter can be controlled [Speed/Direction]
- The centrifugal switch is used to disconnect starting winding at which instant
- Shaded-pole motors have percentage efficiency of ranges
- The revolving field in a shaded-pole single-phase induction motor is produced by using
- The shading coil in a shaded-pole induction motor usually consists of
- For which of the applications a reluctance motor is preferred
- Which type of induction motor is recommended for high speed and high starting torque applications
- A hysteresis motor works on the principle of
- Which of the following motor will provide the highest starting torque
- Rotor slots are skewed in induction motor so as to