|Does the monorail at Disneyland and the metro in D.C. run on the idea of direct current motors? Since they reverse directions? Is it like plugging the train in backwards?
Those trains probably run on AC motors, because then they can use transformers to transfer power between circuits. Most likely, these trains use induction motors. To reverse the direction of the train, the engineer reverses the direction in which magnetic poles in the motors' stators circle the motors' rotors. When the poles reverse directions, the rotor has to reverse its direction, too, so that it chases those poles around in a circle.