单选题The output voltage of a 440 volt, 60 hertz, AC generator is controlled by the ().Aprime mover speedBexciter output voltageCload on the alternatorDnumber of poles

单选题
The output voltage of a 440 volt, 60 hertz, AC generator is controlled by the ().
A

prime mover speed

B

exciter output voltage

C

load on the alternator

D

number of poles


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