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A 440 V dc shunt motors takes an armature current of 20 A and runs at 500 rpm. The armature resistance is 0.6 Ohms. If the flux is reduced by 40 %, calculate the new values of armature current and speed.?
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A 440 V dc shunt motors takes an armature current of 20 A and runs at ...
Original Values:
- Armature current (Ia) = 20 A
- Speed (N) = 500 rpm
- Armature resistance (Ra) = 0.6 Ohms
- Supply voltage (V) = 440 V

Calculation of Back EMF (Eb):
Back EMF (Eb) = V - Ia*Ra
Back EMF = 440 - 20*0.6 = 428 V

Calculation of Flux with 40% reduction:
Original flux (Φ) = Eb / (N * K)
where K is a constant for motor
New flux = 0.6 * Original flux

Calculation of New Armature Current (Ia'):
New back EMF (Eb') = New flux * N * K
New armature current (Ia') = (V - Eb') / Ra

Calculation of New Speed (N'):
New speed (N') = Eb' / (New flux * K)

Substitute the given values into the formulas to find the new values of armature current and speed:
- New armature current (Ia') = (440 - 0.6 * 428) / 0.6 = 16.67 A
- New speed (N') = 0.6 * 428 / (0.4 * 500 * K) = 514.2 rpm
Therefore, after reducing the flux by 40%, the new armature current will be 16.67 A and the new speed will be 514.2 rpm.
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A 440 V dc shunt motors takes an armature current of 20 A and runs at 500 rpm. The armature resistance is 0.6 Ohms. If the flux is reduced by 40 %, calculate the new values of armature current and speed.?
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A 440 V dc shunt motors takes an armature current of 20 A and runs at 500 rpm. The armature resistance is 0.6 Ohms. If the flux is reduced by 40 %, calculate the new values of armature current and speed.? for UPSC 2024 is part of UPSC preparation. The Question and answers have been prepared according to the UPSC exam syllabus. Information about A 440 V dc shunt motors takes an armature current of 20 A and runs at 500 rpm. The armature resistance is 0.6 Ohms. If the flux is reduced by 40 %, calculate the new values of armature current and speed.? covers all topics & solutions for UPSC 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A 440 V dc shunt motors takes an armature current of 20 A and runs at 500 rpm. The armature resistance is 0.6 Ohms. If the flux is reduced by 40 %, calculate the new values of armature current and speed.?.
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