Most Important Synchronous Motor MCQs
Synchronous motors are the electrical machines that convert AC electrical power to mechanical power. Electrical Engineering XYZ shares 10 Most Important synchronous motors MCQs.
Contents
Sort The advantages of amortisseur winding
Sort The advantages of amortisseur winding:
- It increases stability
- It develops torque which is useful for fast machine
- It develops torque which is useful for slow machines
- All of these
Correct answer: 4. All of these
The correct statement about the speed of synchronous motor
The correct statement about the speed of synchronous motor:
- It remains constant from no load to full load
- It increases from no load to full load
- It decreases from no load to full load
- It is pulsating and change at irregular intervals
Correct answer: 1. It remains constant from no load to full load
The synchronous motor is not a self starting motor because
The synchronous motor is not a self starting motor because:
- It uses damper winding
- No stator is present
- The slip is zero in the motor
- The rotor’s instantaneous torque reverses after half cycle
Correct answer: 4. The rotor’s instantaneous torque reverses after half cycle
The overexcited synchronous motor is used to
The overexcited synchronous motor is used to:
- Support the variable loads
- Support loads which have low torque
- Supply reactive power
- None of these
Correct answer: 3. Supply reactive power
Explanation: The overexcited synchronous motor provides reactive power to the power system and it can be used for the power factor correction
The method which can be used to start a synchronous motor
The method which can be used to start a synchronous motor:
- Use an external prime mover
- Reduce the stator frequency to safe point
- Use Amortisseur windings
- All of these
Correct answer: 4. All of these
Speed regulation of the Synchronous motor is
Speed regulation of synchronous motor is:
- 0
- 1
- 10
- 100
Correct answer: 1. 0
The maximum pullout torque in a synchronous motor occurs at
The maximum pullout torque in a synchronous motor occurs at:
- 0º
- 45º
- 60º
- 90º
Correct answer: 4. 90º
Synchronous motors are self-starting, the statement is
Synchronous motors are self-starting, the statement is:
- True
- False
Correct answer: 2. False
The power factor of under excited synchronous motor is
The power factor of under excited synchronous motor is:
- Leading
- Lagging
- Unity
- Zero
Correct answer: 2. Lagging
The percent slip of synchronous motor is
The percent slip of synchronous motor is:
- 0
- 0.5
- 99.5
- 100
Correct answer: a. 0 is the right answer
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