单项选择题
Which of the following components are used to convert alternating current produced in the generator windings to direct current?（）
A.Armature and equalizer B.Commutator and brushes C.Rotor and interpoles D.Field and exciter
单项选择题 In a series circuit, which value will remain unchanged at all places in the circuit?（）
单项选择题 Most conducting materials such as copper, aluminum, iron, nickel, and tungsten （）.
单项选择题 The function of a rectifier is similar to that of a （）.
