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Which of the statements is/are correct regarding rotating magnetic field production in a 3-phase induction machine?
1. The direction of rotation of resultant flux in the air gap depends upon phase sequence.
2. The resultant flux of constant magnitude is produced in the air gap of the motor.
3. Frequency of rotating magnetic field is not the same as that of the supply frequency
1. The direction of rotation of resultant flux in the air gap depends upon phase sequence.
2. The resultant flux of constant magnitude is produced in the air gap of the motor.
3. Frequency of rotating magnetic field is not the same as that of the supply frequency
- a)1, 2 & 3
- b)1
- c)1 & 2
- d)2
Correct answer is option 'C'. Can you explain this answer?
Verified Answer
Which of the statements is/are correct regarding rotating magnetic fie...
Concept:
- If a balanced three-phase voltage is supplied to balanced three-phase windings in the stator of an Induction motor, the resultant flux remains constant in magnitude but rotates at the synchronous speed.
- Synchronous speed is related to the supply frequency and number of poles, for which the winding (stator) has been designed. This is termed as a rotating magnetic field formed in the air gap of the motor.
Where Ns = Synchronous speed in rpm
f = Supply frequency
P = Number of poles
- The direction of rotation of resultant flux in the air gap depends upon phase sequence. It rotates from the leading phase to the lagging phase.
- Frequency of rotating magnetic field is same as that of the supply frequency, while rotor frequency is slip times of supply frequency.
Most Upvoted Answer
Which of the statements is/are correct regarding rotating magnetic fie...
Understanding Rotating Magnetic Field in 3-Phase Induction Machines
In a 3-phase induction machine, the rotating magnetic field is crucial for its operation. Let's analyze the statements provided to understand why options 1 and 2 are correct.
1. Direction of Rotation Depends on Phase Sequence
- The direction of the rotating magnetic field is determined by the sequence of the phases.
- For example, a phase sequence of R-Y-B (Red-Yellow-Blue) results in a clockwise rotation, while Y-B-R (Yellow-Blue-Red) results in a counterclockwise rotation.
- This aspect is fundamental in controlling the operational direction of the induction motor.
2. Resultant Flux of Constant Magnitude
- The rotating magnetic field in the air gap of the motor indeed has a constant magnitude.
- The stator windings are designed such that the resultant magnetic field produced maintains this constant magnitude as it rotates.
- This is essential for ensuring stable motor performance and torque production.
3. Frequency of Rotating Magnetic Field
- The statement regarding the frequency not being the same as that of the supply frequency is incorrect.
- The frequency of the rotating magnetic field is equal to the supply frequency divided by the number of poles in the machine.
- Therefore, this statement does not hold true in the context of a standard 3-phase induction motor.
Conclusion
- The correct statements regarding the rotating magnetic field production in a 3-phase induction machine are 1 and 2.
- Thus, the appropriate answer choice is "C" (1 & 2).
- This understanding is vital for the effective operation and control of induction machines in various electrical applications.
In a 3-phase induction machine, the rotating magnetic field is crucial for its operation. Let's analyze the statements provided to understand why options 1 and 2 are correct.
1. Direction of Rotation Depends on Phase Sequence
- The direction of the rotating magnetic field is determined by the sequence of the phases.
- For example, a phase sequence of R-Y-B (Red-Yellow-Blue) results in a clockwise rotation, while Y-B-R (Yellow-Blue-Red) results in a counterclockwise rotation.
- This aspect is fundamental in controlling the operational direction of the induction motor.
2. Resultant Flux of Constant Magnitude
- The rotating magnetic field in the air gap of the motor indeed has a constant magnitude.
- The stator windings are designed such that the resultant magnetic field produced maintains this constant magnitude as it rotates.
- This is essential for ensuring stable motor performance and torque production.
3. Frequency of Rotating Magnetic Field
- The statement regarding the frequency not being the same as that of the supply frequency is incorrect.
- The frequency of the rotating magnetic field is equal to the supply frequency divided by the number of poles in the machine.
- Therefore, this statement does not hold true in the context of a standard 3-phase induction motor.
Conclusion
- The correct statements regarding the rotating magnetic field production in a 3-phase induction machine are 1 and 2.
- Thus, the appropriate answer choice is "C" (1 & 2).
- This understanding is vital for the effective operation and control of induction machines in various electrical applications.
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Community Answer
Which of the statements is/are correct regarding rotating magnetic fie...
Concept:
- If a balanced three-phase voltage is supplied to balanced three-phase windings in the stator of an Induction motor, the resultant flux remains constant in magnitude but rotates at the synchronous speed.
- Synchronous speed is related to the supply frequency and number of poles, for which the winding (stator) has been designed. This is termed as a rotating magnetic field formed in the air gap of the motor.
Where Ns = Synchronous speed in rpm
f = Supply frequency
P = Number of poles
- The direction of rotation of resultant flux in the air gap depends upon phase sequence. It rotates from the leading phase to the lagging phase.
- Frequency of rotating magnetic field is same as that of the supply frequency, while rotor frequency is slip times of supply frequency.
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Which of the statements is/are correct regarding rotating magnetic field production in a 3-phase induction machine?1. The direction of rotation of resultant flux in the air gap depends upon phase sequence.2. The resultant flux of constant magnitude is produced in the air gap of the motor.3. Frequency of rotating magnetic field is not the same as that of the supply frequencya)1, 2 & 3b)1c)1 & 2d)2Correct answer is option 'C'. Can you explain this answer? for Electrical Engineering (EE) 2026 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Which of the statements is/are correct regarding rotating magnetic field production in a 3-phase induction machine?1. The direction of rotation of resultant flux in the air gap depends upon phase sequence.2. The resultant flux of constant magnitude is produced in the air gap of the motor.3. Frequency of rotating magnetic field is not the same as that of the supply frequencya)1, 2 & 3b)1c)1 & 2d)2Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2026 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the statements is/are correct regarding rotating magnetic field production in a 3-phase induction machine?1. The direction of rotation of resultant flux in the air gap depends upon phase sequence.2. The resultant flux of constant magnitude is produced in the air gap of the motor.3. Frequency of rotating magnetic field is not the same as that of the supply frequencya)1, 2 & 3b)1c)1 & 2d)2Correct answer is option 'C'. Can you explain this answer?.
Which of the statements is/are correct regarding rotating magnetic field production in a 3-phase induction machine?1. The direction of rotation of resultant flux in the air gap depends upon phase sequence.2. The resultant flux of constant magnitude is produced in the air gap of the motor.3. Frequency of rotating magnetic field is not the same as that of the supply frequencya)1, 2 & 3b)1c)1 & 2d)2Correct answer is option 'C'. Can you explain this answer? for Electrical Engineering (EE) 2026 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about Which of the statements is/are correct regarding rotating magnetic field production in a 3-phase induction machine?1. The direction of rotation of resultant flux in the air gap depends upon phase sequence.2. The resultant flux of constant magnitude is produced in the air gap of the motor.3. Frequency of rotating magnetic field is not the same as that of the supply frequencya)1, 2 & 3b)1c)1 & 2d)2Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2026 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the statements is/are correct regarding rotating magnetic field production in a 3-phase induction machine?1. The direction of rotation of resultant flux in the air gap depends upon phase sequence.2. The resultant flux of constant magnitude is produced in the air gap of the motor.3. Frequency of rotating magnetic field is not the same as that of the supply frequencya)1, 2 & 3b)1c)1 & 2d)2Correct answer is option 'C'. Can you explain this answer?.
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