Electromagnetic Induction

Faraday's law of induction, Lenz's rule, induced electromotive force, and eddy currents.

General idea of the topic

Electromagnetic induction studies how a time-varying magnetic flux generates electromotive force and current in a circuit, connecting the temporal change of the field with a measurable and technologically exploitable electrical response.

The block covers from Faraday's law and Lenz's law to self-inductance, mutual inductance and applications in generators and transformers, closing the link between magnetism and circuits.

What you will truly understand

• How the variation of magnetic flux produces induced EMF according to Faraday's law.
• How Lenz's law determines the direction of induced current through energy conservation.
• How self-induction and mutual inductance store energy in the magnetic field.
• How to apply these principles to generators, transformers and transient circuits.

Recommended learning route

1. Faraday's law and induced EMF: flux, time variation and sign.
2. Inductance: self-induction, stored energy and RL circuits.
3. Applications: generators, transformers and eddy currents.

Physical criterion you must acquire

Always identify the cause of the flux change (motion, field variation or area change) before applying Faraday's law. Verify the sign with Lenz's law and energy coherence of the result.

Connection with real problems

Electric generators, power transformers, induction braking, induction cookers and wireless charging.

Final goal of the topic

Solve induction problems with flux traceability, coherent sign and energy criterion.