In discussing motors, one college textbook says, "As the coil (of a motor) rotates in a magnetic field, a back emf is generated that tends to counter the emf that supplies the current." This is a true statement, but it does little to enhance student understanding of how and why it is created. In this paper, I will explain how to take students step by step through the creation of what the experts call "back emf" and then describe a simple experiment that clearly demonstrates its existence.