De la spire circulaire au solénoïde en 3D
A solenoid is simply a stack of circular coils, and this 3D simulation builds one loop at a time so you can watch the field evolve. What starts as separate doughnut-shaped fields merges into the familiar uniform interior field of a long solenoid.
Comment utiliser cette simulation
- Add coils one at a time and watch the field build
- Vary the spacing between turns and the current
- Rotate the 3D view and slice through the solenoid
Ce qu’il faut observer
- The interior field becomes progressively more uniform as turns are added
- External field lines largely cancel out along the length
- Field strength depends on turns per unit length, not on the total number of turns alone
La physique derrière
Each turn produces a circular field pattern. Stacked together, the fields inside reinforce while those outside largely cancel, producing a nearly uniform interior field B = μ₀nI, where n is turns per unit length. The field outside a long solenoid is very weak, and the ends are where the uniform approximation breaks down.