The efficiency of a dc series machine cannot be determined by ___

The efficiency of a dc series machine cannot be determined by Swinburne’s test as

A. a series motor has very high starting torque.
B. a series motor draws excessive current from the supply mains on no load.
C. a series motor runs at dangerously high speed on no load. [Correct Answer]
D. all of the above.

Show Answer

Answer: C

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