Dynamic Electricity and Electromagnetism — Chapter 3: Electromagnetic induction

About this lesson

This unit covers the principles of electromagnetic induction, starting with Faraday's experiments and laws, and Lenz's rule. It explains how a changing magnetic flux induces an electromotive force (emf) in a coil, with the direction given by Lenz's rule and Fleming's right-hand rule. The unit then explores mutual induction between two coils, self-induction in a single coil, and eddy currents. It derives the emf induced in a moving straight wire and applies this to the alternating current (AC) generator, including the sinusoidal variation of emf and the effective values of AC. The unit also describes how to convert an AC generator to a DC generator using a commutator, and explains the transformer's operation, including the relationships between voltages, currents, and turns, and the concept of efficiency. Finally, it introduces the DC motor, which converts electrical energy to mechanical energy, and explains its operation using Fleming's left-hand rule.