单项选择题
A.wasted energy
B.efficient operation
C.a short in the exciter field windings
D.an excessive number of minor system grounds
单项选择题 An alternator is being paralleled with one on the lineAt the INSTANT the circuit breaker is closed, the frequency of the incoming alternator will normally （）.
单项选择题 Current flowing in only one direction is called （）
单项选择题 Accidental grounds in a shipboard electrical system must be repaired as soon as possible as they will （）