3D Magnetic Field Visualizer
Explore 3D field lines around bar and horseshoe magnets. Drag magnets to move them; compass needles (green) align with the local B field.
Controls
12 lines
1.0×
Live Data
Configuration
Bar magnet
|B| at probe
—
Field lines
0
Legend
- North Pole (N)
- South Pole (S)
- Magnetic Field B (N → S)
- Compass Needles
Key Concepts
- Like poles repel; unlike poles attract.
- Field lines go from N to S outside the magnet and form closed loops.
- A compass needle aligns with the local field direction.
- Field strength is stronger where lines are closer together.
Dipole Model
$\vec{B} \propto \dfrac{\vec{m}}{r^3}$ (far field)
Each magnet is modelled as N and S monopoles. The net field is their superposition. Lines never cross; density indicates |B|.