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If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed will
- a)Decrease by 10%
- b)Remain unchanged
- c)Increase 10%
- d)Increase by 20%
Correct answer is option 'C'. Can you explain this answer?
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Verified Answer
If the load current and flux of a DC motor are held constant, and volt...
We know that, in a dc motor
As voltage applied across its armature is increased by 10%, back emf also gets increased by 10%.
As flux is constant and speed is directly proportional to back emf, speed also gets increased by 10%.
As voltage applied across its armature is increased by 10%, back emf also gets increased by 10%.
As flux is constant and speed is directly proportional to back emf, speed also gets increased by 10%.
Most Upvoted Answer
If the load current and flux of a DC motor are held constant, and volt...
The correct answer is option 'C' - the speed of the DC motor will increase by 10%.
Here's an explanation of why this is the case:
1. Relationship between voltage, current, and speed:
In a DC motor, the speed is directly proportional to the voltage applied to the armature. This means that if the voltage increases, the speed of the motor will also increase, assuming that the load current and flux are held constant.
2. Effect of increased voltage:
When the voltage applied across the armature of the DC motor is increased by 10%, it means that the voltage is 110% of its original value. Since the speed is directly proportional to the voltage, the speed of the motor will also increase by the same percentage.
3. Mathematical explanation:
Let's assume that the original voltage applied to the armature is V, and the original speed of the motor is S. When the voltage is increased by 10%, the new voltage applied will be 1.1V. As the speed is directly proportional to the voltage, the new speed of the motor will be 1.1S, which is a 10% increase from the original speed.
4. Example:
For example, if the original voltage applied to the armature is 100 volts and the original speed of the motor is 1000 RPM (revolutions per minute), when the voltage is increased by 10% to 110 volts, the new speed of the motor will be 1100 RPM. This is a 10% increase in speed.
In conclusion, when the voltage applied across the armature of a DC motor is increased by 10% while keeping the load current and flux constant, the speed of the motor will increase by 10%. This is because the speed of the motor is directly proportional to the voltage applied.
Here's an explanation of why this is the case:
1. Relationship between voltage, current, and speed:
In a DC motor, the speed is directly proportional to the voltage applied to the armature. This means that if the voltage increases, the speed of the motor will also increase, assuming that the load current and flux are held constant.
2. Effect of increased voltage:
When the voltage applied across the armature of the DC motor is increased by 10%, it means that the voltage is 110% of its original value. Since the speed is directly proportional to the voltage, the speed of the motor will also increase by the same percentage.
3. Mathematical explanation:
Let's assume that the original voltage applied to the armature is V, and the original speed of the motor is S. When the voltage is increased by 10%, the new voltage applied will be 1.1V. As the speed is directly proportional to the voltage, the new speed of the motor will be 1.1S, which is a 10% increase from the original speed.
4. Example:
For example, if the original voltage applied to the armature is 100 volts and the original speed of the motor is 1000 RPM (revolutions per minute), when the voltage is increased by 10% to 110 volts, the new speed of the motor will be 1100 RPM. This is a 10% increase in speed.
In conclusion, when the voltage applied across the armature of a DC motor is increased by 10% while keeping the load current and flux constant, the speed of the motor will increase by 10%. This is because the speed of the motor is directly proportional to the voltage applied.
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If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed willa)Decrease by 10%b)Remain unchangedc)Increase 10%d)Increase by 20%Correct answer is option 'C'. Can you explain this answer?
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If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed willa)Decrease by 10%b)Remain unchangedc)Increase 10%d)Increase by 20%Correct answer is option 'C'. Can you explain this answer? for Railways 2024 is part of Railways preparation. The Question and answers have been prepared according to the Railways exam syllabus. Information about If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed willa)Decrease by 10%b)Remain unchangedc)Increase 10%d)Increase by 20%Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Railways 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed willa)Decrease by 10%b)Remain unchangedc)Increase 10%d)Increase by 20%Correct answer is option 'C'. Can you explain this answer?.
If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed willa)Decrease by 10%b)Remain unchangedc)Increase 10%d)Increase by 20%Correct answer is option 'C'. Can you explain this answer? for Railways 2024 is part of Railways preparation. The Question and answers have been prepared according to the Railways exam syllabus. Information about If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed willa)Decrease by 10%b)Remain unchangedc)Increase 10%d)Increase by 20%Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Railways 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If the load current and flux of a DC motor are held constant, and voltage applied across its armature is increased by 10%, its speed willa)Decrease by 10%b)Remain unchangedc)Increase 10%d)Increase by 20%Correct answer is option 'C'. Can you explain this answer?.
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