For a D.C. shunt motor if the excitation is changed_______________?
Correct answer: B. torque will change but power will remain constant
- A. torque will remain constant
- B. torque will change but power will remain constant
- C. torque and power both will change
- D. torque, power and speed, all will change
Explanation
Changing shunt-field excitation changes flux and speed; under the usual field-control assumption, the motor operates approximately at constant power, so torque changes inversely with speed. Thus torque changes while power remains approximately constant.
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