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In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation will
- a)Improve and the speed falls
- b)Deteriorate and the speed rises
- c)Deteriorate and the speed falls
- d)Improve and the speed rises
Correct answer is option 'C'. Can you explain this answer?
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Verified Answer
In a loaded dc motor, if the brushes are given a shift from the inter-...
In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation will deteriorate
The armature reaction is partially magnetizing due to horizontal component and partially cross magnetizing due to vertical component. The flux will increase and hence there will be reduction in speed
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In a loaded dc motor, if the brushes are given a shift from the inter-...
Effect of Brush Shift on Commutation and Speed in Loaded DC Motor
When the brushes of a loaded DC motor are shifted from the inter-pole axis in the direction of rotation, it can have the following effects on commutation and speed:
Commutation Deteriorates:
- Commutation is the process of exchanging the current between the armature conductors and the external circuit through the brushes and commutator segments.
- In a loaded DC motor, the armature reaction causes the brushes to shift from the neutral axis or inter-pole axis.
- This shift creates a non-uniform magnetic field around the brushes and commutator segments.
- When the brush shift is in the direction of rotation, the commutator segments that are ahead of the brushes experience a higher current density and wear out faster, while the segments behind the brushes receive a lower current density and may not be fully discharged.
- This leads to sparking, arcing, and brush wear, which can cause poor commutation, increased electromagnetic interference (EMI), and reduced motor efficiency and reliability.
Speed Falls:
- The brush shift also affects the speed of the loaded DC motor.
- As the commutation deteriorates, the motor torque and power output decrease, and the motor speed falls.
- This is because the armature current and voltage waveforms become distorted, and the motor operates at a lower power factor and efficiency.
- The speed regulation of the motor also becomes poor, meaning that the motor speed varies widely with changes in the load and supply voltage.
Therefore, we can conclude that if the brushes are given a shift from the inter-pole axis in the direction of rotation in a loaded DC motor, the commutation will deteriorate, and the speed will fall.
When the brushes of a loaded DC motor are shifted from the inter-pole axis in the direction of rotation, it can have the following effects on commutation and speed:
Commutation Deteriorates:
- Commutation is the process of exchanging the current between the armature conductors and the external circuit through the brushes and commutator segments.
- In a loaded DC motor, the armature reaction causes the brushes to shift from the neutral axis or inter-pole axis.
- This shift creates a non-uniform magnetic field around the brushes and commutator segments.
- When the brush shift is in the direction of rotation, the commutator segments that are ahead of the brushes experience a higher current density and wear out faster, while the segments behind the brushes receive a lower current density and may not be fully discharged.
- This leads to sparking, arcing, and brush wear, which can cause poor commutation, increased electromagnetic interference (EMI), and reduced motor efficiency and reliability.
Speed Falls:
- The brush shift also affects the speed of the loaded DC motor.
- As the commutation deteriorates, the motor torque and power output decrease, and the motor speed falls.
- This is because the armature current and voltage waveforms become distorted, and the motor operates at a lower power factor and efficiency.
- The speed regulation of the motor also becomes poor, meaning that the motor speed varies widely with changes in the load and supply voltage.
Therefore, we can conclude that if the brushes are given a shift from the inter-pole axis in the direction of rotation in a loaded DC motor, the commutation will deteriorate, and the speed will fall.
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In a loaded dc motor, if the brushes are given a shift from the inter-...
Forward m deteriorate hoga and backward m improve hoga.
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In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation willa)Improve and the speed fallsb)Deteriorate and the speed risesc)Deteriorate and the speed fallsd)Improve and the speed risesCorrect answer is option 'C'. Can you explain this answer?
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In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation willa)Improve and the speed fallsb)Deteriorate and the speed risesc)Deteriorate and the speed fallsd)Improve and the speed risesCorrect answer is option 'C'. Can you explain this answer? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation willa)Improve and the speed fallsb)Deteriorate and the speed risesc)Deteriorate and the speed fallsd)Improve and the speed risesCorrect answer is option 'C'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation willa)Improve and the speed fallsb)Deteriorate and the speed risesc)Deteriorate and the speed fallsd)Improve and the speed risesCorrect answer is option 'C'. Can you explain this answer?.
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In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation willa)Improve and the speed fallsb)Deteriorate and the speed risesc)Deteriorate and the speed fallsd)Improve and the speed risesCorrect answer is option 'C'. Can you explain this answer?, a detailed solution for In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation willa)Improve and the speed fallsb)Deteriorate and the speed risesc)Deteriorate and the speed fallsd)Improve and the speed risesCorrect answer is option 'C'. Can you explain this answer? has been provided alongside types of In a loaded dc motor, if the brushes are given a shift from the inter-pole axis in the direction of rotation, then the commutation willa)Improve and the speed fallsb)Deteriorate and the speed risesc)Deteriorate and the speed fallsd)Improve and the speed risesCorrect answer is option 'C'. Can you explain this answer? theory, EduRev gives you an
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