单项选择题
A.Glass B.Bakelite C.Soft iron D.Aluminum
An ohmmeter can be used to measure（）A.current flow in a...
单项选择题An ohmmeter can be used to measure（）
A.current flow in a circuit B.voltage between two points in a circuit C.circuit continuity D.power
The instantaneous reduction in voltage of an AC generat...
单项选择题The instantaneous reduction in voltage of an AC generator, resulting from an increase in load, and prior to the automatic voltage regulator correcting the situation, is called voltage （）.
A.droop B.drop C.dip D.regulation
If both the “high level” and “low level” alarms come on...
单项选择题If both the “high level” and “low level” alarms come on for the same address of a centralized control console, the most likely problem is a/an （）.
A.sensor failure B.failed alarm C.low level D.extremely high level
