The "back emf" of a motor refers to a source of voltage that
A)occurs when the motor runs backwards.
B)occurs when the motor is used as a generator.
C)is biggest when the current through the motor is biggest.
D)is biggest when the motor turns fastest.

Question

Quizplus · Accepted Answer

Back emf is generated by the motor's rotation and is proportional to the speed of the motor; it is largest when the motor turns fastest.

The "Back Emf" of a Motor Refers to a Source