【判断题】李斯特有大量粉丝,深受贵族妇女的欢迎,是沙龙中的常客。
【简答题】革兰氏染色结果,G-为 色,G+为 色。
【单选题】An alternator switchboard has a synchroscope and synchronizing lamps, if the synchroscope is broken, which of the steps listed is the most essential before an alternator can be paralleled with the bus...
A.
The breaker should be closed when one synchronizing lamp is dark and the other is bright
B.
The breaker should be closed when both synchronizing lamps are bright
C.
The frequency meter should be used to determine that the incoming alternator frequency is slightly higher than the bus
D.
A portable phase sequence indicator must be used to verify the information from the lamps
【单选题】What is the purpose of the alternator reverse power trip?
A.
To prevent the alternator from “motoring” by being supplied power from other parallel alternator
B.
To prevent parallel operation if the excitation field voltage is reversed
C.
To prevent the alternator from being paralleled if it is out of phase with the main switchboard
D.
To give automatic disconnection of the circuit breaker when you are taking the alternator off the switchboard