What is Faraday's Law of Induction?
The induced EMF equals the negative rate of change of magnetic flux: EMF = −dΦ/dt. For an N-turn coil: EMF = −N • dΦ/dt. The negative sign reflects Lenz's Law.

How is Lenz's Law applied?

Lenz's Law: the induced current flows so that its magnetic field opposes the flux change that caused it. Applications include determining induced current direction, explaining electromagnetic braking, and understanding back-EMF in motors and transformers.

What are self-inductance and mutual inductance?
• Self-inductance (L): a coil's ability to induce EMF in itself due to its own changing current. L = NΦ/I, unit: Henry (H).
• Mutual inductance (M): one coil's changing current induces EMF in another coil — the core principle of transformers.
 

What is Ampere's Law?

Ampere's Law: the line integral of H around a closed path equals the enclosed current: ∮H • dl = I_enc. Used to calculate magnetic fields in symmetric structures such as toroids and coaxial cables.