单项选择题
The energy consumed by an AC motor, as strictly reactive power, is （）
A.used to do mechanical work B.used to establish the magnetic field of the motor C.lost as heat generated by the windings D.lost in doing work to turn the motor itself
单项选择题 A diesel driven emergency generator is prevented from being paralleled with the ships service generators by （）
单项选择题 A motor enclosure which protects against falling liquids is classified as （）
单项选择题 Universal motors will operate on AC or DC current, and are generally found in （）
