单项选择题
A.generate its own electrical power B.transform electrical energy into mechanical energy C.increase or decrease circuit voltage as required D.convert AC current to DC current
When placed in a magnetic field, which of the materials...
单项选择题When placed in a magnetic field, which of the materials listed will maintain the highest permeability?（）
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
