Concept preview

What you will be able to do

1. 01Explain how a motor and a generator are the same device run in reverse
2. 02Describe how a generator produces alternating current
3. 03Apply the transformer equation and explain AC power transmission

This whole chapter comes together in three machines that quietly run the modern world. They all spring from just two facts: a current in a field feels a force (the motor effect, $F = BIL$) and a changing flux induces a current (Faraday's law). The motor uses the first, the generator uses the second, and the transformer uses induction between two coils. Master these and you understand how electricity is made, moved, and used.