If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens__________?
Correct answer: C. this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses D. motor will run at very slow speed
- A. nothing will happen to the motor
- B. this will make armature to take heavy current, possibly burning it
- C. this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses D. motor will run at very slow speed
Explanation
If the shunt field opens, the motor flux collapses while the applied voltage remains, causing a dangerous rise in speed. The armature may be damaged by excessive centrifugal stress, so option c is correct.
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