单项选择题
A.phase angle B.frequency C.wave form D.half mode
Complete maintenance of electrical motors should includ...
单项选择题Complete maintenance of electrical motors should include periodic checks for machine （）
A.vibration B.watertight integrity C.speed droop D.reactive power
The frequency of an alternator is controlled from the m...
单项选择题The frequency of an alternator is controlled from the main switchboard by adjusting the（）
A.frequency meter B.voltage regulator C.governor control D.sychroscope switch
The frequency of an AC generator is controlled by the （...
单项选择题The frequency of an AC generator is controlled by the （）
A.rheostat B.governor C.exciter D.capacitor
