Electrical Engineering (EE) Exam > Electrical Engineering (EE) Questions > Due to which of the following reasons a synch...
Start Learning for Free
Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?
- a)High field current
- b)Low short circuit ratio
- c)High core losses
- d)Low field current
Correct answer is option 'D'. Can you explain this answer?
Most Upvoted Answer
Due to which of the following reasons a synchronous motor fails to pul...
Reasons for failure of synchronous motor to pull into synchronism
There can be several reasons for a synchronous motor to fail to pull into synchronism after applying D.C. field current. However, the correct reason among the given options is low field current.
Explanation
Synchronous motor operates at synchronous speed, which is determined by the supply frequency and the number of poles of the motor. In order to achieve this synchronous speed, the rotor of the motor must rotate at the same speed as the rotating magnetic field produced by the stator. For this purpose, the motor must be first brought into synchronism.
The process of bringing the rotor of the synchronous motor into synchronism with the rotating magnetic field produced by the stator is known as synchronization. This is achieved by adjusting the D.C. field current of the motor.
However, if the field current is too low, the magnetic field produced by the rotor will be weak, and as a result, the rotor will not be able to lock into the rotating magnetic field of the stator. This will cause the motor to fail to pull into synchronism.
Therefore, low field current is the reason for the failure of a synchronous motor to pull into synchronism after applying D.C. field current.
Other reasons that can cause the failure of synchronous motor to pull into synchronism are:
- High field current: High field current can cause magnetic saturation, which can lead to instability of the motor and failure to pull into synchronism.
- Low short circuit ratio: Low short circuit ratio can cause the motor to have low torque, which can prevent it from pulling into synchronism.
- High core losses: High core losses can cause the motor to have low efficiency, which can prevent it from pulling into synchronism.
There can be several reasons for a synchronous motor to fail to pull into synchronism after applying D.C. field current. However, the correct reason among the given options is low field current.
Explanation
Synchronous motor operates at synchronous speed, which is determined by the supply frequency and the number of poles of the motor. In order to achieve this synchronous speed, the rotor of the motor must rotate at the same speed as the rotating magnetic field produced by the stator. For this purpose, the motor must be first brought into synchronism.
The process of bringing the rotor of the synchronous motor into synchronism with the rotating magnetic field produced by the stator is known as synchronization. This is achieved by adjusting the D.C. field current of the motor.
However, if the field current is too low, the magnetic field produced by the rotor will be weak, and as a result, the rotor will not be able to lock into the rotating magnetic field of the stator. This will cause the motor to fail to pull into synchronism.
Therefore, low field current is the reason for the failure of a synchronous motor to pull into synchronism after applying D.C. field current.
Other reasons that can cause the failure of synchronous motor to pull into synchronism are:
- High field current: High field current can cause magnetic saturation, which can lead to instability of the motor and failure to pull into synchronism.
- Low short circuit ratio: Low short circuit ratio can cause the motor to have low torque, which can prevent it from pulling into synchronism.
- High core losses: High core losses can cause the motor to have low efficiency, which can prevent it from pulling into synchronism.
Free Test
FREE
| Start Free Test |
Community Answer
Due to which of the following reasons a synchronous motor fails to pul...
In a synchronous motor, we provide DC excitation to produce require a magnetic field.
This magnetic field generates the back emf in the synchronous motor.
The low field current is the main reason when the synchronous motor fails to pull into synchronous after applying the D.C. field current.
Lowering the field strength lowers the internally generally generated voltage.
So if the value of excitation is low we can’t generate the required magnetic field and hence back emf will is low.
When the machine fails to pull into synchronism it operates as an induction motor at a speed slightly less than synchronous speed.
Therefore the synchronous motor can’t attend the synchronous speed.
This magnetic field generates the back emf in the synchronous motor.
The low field current is the main reason when the synchronous motor fails to pull into synchronous after applying the D.C. field current.
Lowering the field strength lowers the internally generally generated voltage.
So if the value of excitation is low we can’t generate the required magnetic field and hence back emf will is low.
When the machine fails to pull into synchronism it operates as an induction motor at a speed slightly less than synchronous speed.
Therefore the synchronous motor can’t attend the synchronous speed.
|
Explore Courses for Electrical Engineering (EE) exam
|
|
Top Courses for Electrical Engineering (EE)View all
Question Description
Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? for Electrical Engineering (EE) 2025 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer?.
Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? for Electrical Engineering (EE) 2025 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer?.
Solutions for Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? in English & in Hindi are available as part of our courses for Electrical Engineering (EE).
Download more important topics, notes, lectures and mock test series for Electrical Engineering (EE) Exam by signing up for free.
Here you can find the meaning of Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice Due to which of the following reasons a synchronous motor fails to pull into synchronism after applying D.C. field current?a)High field currentb)Low short circuit ratioc)High core lossesd)Low field currentCorrect answer is option 'D'. Can you explain this answer? tests, examples and also practice Electrical Engineering (EE) tests.
|
|
Explore Courses for Electrical Engineering (EE) exam
|
|
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
|
Signup to see your scores
go up
within 7 days!
within 7 days!
Takes less than 10 seconds to signup