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單項(xiàng)選擇題

The frequency of the alternating current generated by a synchronous generator is governed by the speed and the（）

A.full excitation
B.load
C.power factor
D.number of poles

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單項(xiàng)選擇題

When two DC generators operate in parallel, they are protected against motorizing by（）

A.blow out coils
B.governor relay
C.under voltage trips
D.reverse current trips

單項(xiàng)選擇題

The correct phase rotation of a three-phase alternator can be checked with a（）

A.dynamometer
B.power factor meter
C.three-phase motor
D.polyphase voltmeter

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