单选题The output voltage of a three-phase alternator is regulated by the （）.AAC voltage to the armatureBAC voltage to the fieldCDC voltage to the armatureDDC voltage to the field
单选题
The output voltage of a three-phase alternator is regulated by the （）.
A
AC voltage to the armature
B
AC voltage to the field
C
DC voltage to the armature
D
DC voltage to the field
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