单项选择题
With No~1 and No~2 alternators running in parallel and the KW loads equally shared, one alternator is drawing much higher current than the other.What does this indicate?（）
A.The alternators are not generating the same voltages and should be adjusted on automatic voltage regulator rheostats
B.Alternator frequencies are different and should be adjusted on the governor speed controllers
C.Alternators are out of phase and should be tripped and paralleled again
D.One alternator has lost one of its phases
相关考题
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单项选择题
Operational amplifiers, used primarily in analog circuits, are characterized by（）
A.high input impedance, high gain and low output impedance
B.high input impedance, high gain and high output impedance
C.low input impedance, low gain and high output impedance
D.low input impedance, high gain and low output impedance -
单项选择题
CFC refrigerants exposed to high temperature or direct flame, will decompose and may produce（）
A.methyl chloride
B.ammonia
C.hydrofluoric acid
D.ozone -
单项选择题
The major difference between the discharge and suction valves installed in most low pressure, reciprocating air compressors is that（）
A.one valve seats upwards, while the other seats downwards
B.the reed valves used on the discharge are made substantially thicker and heavier than the suction valves
C.the suction valve springs exert a greater tension than the discharge valve springs
D.the discharge valve springs exert a greater tension than the suction valve springs
