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单选题
The alternating current generator supplying a load has a voltage drop resulted from the loadWhen the load has a lagging power factor this voltage drop （）.
A
is small
B
may be neglected
C
is useful
D
is considerable
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单选题Which of the following components are used to convert alternating current produced in the generator windings to direct current?（）A
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There are three phase windings on the rotorD
The generator has brushes
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