Electromagnetic Induction

Φ = B·A·cosθ. Tilt the loop and watch flux follow a cosine curve.

ε = −N·dΦ/dt. Move a magnet near a coil and watch the galvanometer needle.

Induced current opposes the change in flux — repels approaching magnet, attracts retreating.

ε = BLv. Rod sliding on rails through B field generates current and feels back-force.

Changing B induces E circulating around it. E ∝ r inside, ∝ 1/r outside.

L = μ₀N²A/ℓ. RL circuit current I(t) = I∞(1 − e^(−t/τ)), τ = L/R.

Two coupled coils. M = μ₀N₁N₂A/ℓ. ε₂ = −M·dI₁/dt with 90° phase shift.

Solid plate damps quickly in B; slotted plate barely damps. Lenz dissipation.