SACE Stage 2 Physics — Electricity & Magnetism 2.4

Two Parallel Wires

Two long straight wires each set up their own circular magnetic field; each then sits in the other's field and feels a force. Parallel currents attract, antiparallel currents repel: F/ℓ = μ₀ I₁ I₂ / 2π d. Drag to orbit; switch to End-on or Side for the textbook cross-sections.