Induction Motor MCQs Part 1
An induction motor is a popular machine that is widely employed in industries. Given below is Induction Motor MCQs Part 1.
Also, check List of other Induction Motor MCQs
Contents
Crawling in an induction motor is caused by
1. Crawling in an induction motor is caused by:
- Harmonics
- Low voltage
- High voltage
- Design fault
Correct answer: 1. Harmonics
The crawling in motors is solved by
2. The crawling in motors is solved by:
- Skewing
- Changing stator
- Decreasing FLA
- Increasing FLA
Correct answer: 1. Skewing
Schrage motor is
3. Schrage motor is:
- An induction motor
- A frequency changer
- Useful for shunt speed-torque drives
- All of above
Correct answer: 4. All of above
Starting torque of slip ring induction motor is
4. Starting torque of slip ring induction motor is:
- Very high
- Medium
- Low
- Zero
Correct answer: 1. Very high
DC excitation in induction motors
5. DC excitation in induction motors:
- Should be very high
- Should increase exponentially
- Is not required
- None of these
Correct answer: 1. Is not required
At the start, the frequency of induced e.m.f in the rotor is
6. At the start, the frequency of induced e.m.f in the rotor is:
- Same as the applied voltage to the stator
- 2 Times higher than the applied voltage to the stator
- Half the applied voltage
- Zero
Correct answer: 1. Same as the applied voltage to the stator
The resistance of squirrel cage rotor is
7. The resistance of squirrel cage rotor is:
- Infinite
- Very high
- Very small
- Zero
Correct answer: 3. Very small
The speed of rotating magnetic field in 4 pole induction motor operating at 50 Hz is
8. The speed of rotating magnetic field in 4 pole induction motor operating at 50 Hz is:
- 1500 RPM
- 3000 RPM
- 4500 RPM
- 6000 RPM
Correct answer: 1. 1500 RPM
Explanation: Speed = 120 * f / P = 120 * 50 / 4 = 1500 RPM
The power factor of squirrel cage induction motor is
9. The power factor of squirrel cage induction motor is:
- Low at no load
- Low at high loads
- Both of these
- None of these
Correct answer: 1. Low at no load
Higher the number of poles
10. Higher the number of poles:
- Higher the speed
- Lower the speed
- Speed has no impact
Correct answer: 2. Low the speed