http://rawmarks.info/wiki/index.php?title=Main_Page&action=editsome people just fake it as well, cause anybody can edit it
It was a bad question because the diagram didn't show the section of the motor where the split ring commutator would've been located. However, because the question said that it was a DC motor, you can infer that a split ring commutator was therefor a DC motor does the force direction actually change every 180 deg? Wouldn't it only change if there WASNT a SRC? so shouldnt force direction be constant?