【Daily Topic】【Electrical Edition 20170515】
Thread Content
Participation reward: 2 Wealth. Correct reward: 6 wealth. Multiple-choice question: The method to make a DC motor rotate in the forward and reverse directions is ( ). A. Simultaneously change the positive and negative terminals of the power supply for both the excitation winding and the armature winding. B. Only change the positive and negative terminals of the power supply for the excitation winding. C. Change the magnitude of the current in the excitation winding. B
B. The method of making a DC motor rotate in the forward or reverse direction by only changing the positive and negative terminals of the power supply to the excitation winding (B. Only change the positive and negative terminals of the power supply to the excitation winding). A. Change the positive and negative terminals of both the excitation winding and the armature winding simultaneously. B. Only change the positive and negative terminals of the power supply to the excitation winding. C. Change the magnitude of the current in the excitation winding
B. Only change the positive and negative terminals of the excitation winding supply