Question 229Electricity/Electronics - Assistant Engineer70% to pass
Concerning the operating characteristics of a synchronous motor, what statement is true?
AI Explanation
The correct answer is D) The synchronous motor initially starts as an induction motor and when it approaches synchronous speed, the motor then runs as a synchronous motor.
This is because a synchronous motor requires an external source to start it and bring it up to near-synchronous speed. Once it reaches near-synchronous speed, the motor can then be switched to run as a synchronous motor, which maintains a constant speed based on the frequency of the power supply.
The other options are incorrect because they do not accurately describe the starting and operating characteristics of a synchronous motor. Option A is incorrect as the motor does not start as a synchronous motor. Option B is incorrect as the motor does not run as an induction motor once it approaches synchronous speed. Option C is incorrect as the motor does not start as an induction motor.
Related Questions
#227 Which of the following statements represents the main difference between a relay and a contactor? #228 By what means is a synchronous motor started and brought nearly to synchronous speed? #230 Occasionally a synchronous motor is configured without an external shaft to drive a load. In this case, the sole purpose of the synchronous motor is improving overall power factor of an electrical distribution system. What is the name of the synchronous motor so constructed? #231 Assuming that a three phase synchronous motor is separately excited, what statement is true concerning power supplies? #232 Not only can a synchronous motor drive a load with greater efficiency than an induction motor, a fringe benefit of the synchronous motor is the ability for power factor correction. What statement is true?