单项选择题
A.capacitive circuit B.inductive circuit C.magnetic circuit D.resistive circuit
The number of cycles per second occurring in AC voltage...
单项选择题The number of cycles per second occurring in AC voltage is known as the （）
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
