Magnetic Field Lines Explorer
Observe how iron filings align along the magnetic field lines of a bar magnet. The filings form characteristic patterns that reveal the invisible magnetic field structure. Adjust the magnet position and filings density to explore different configurations.
Iron filings align along the magnetic field lines, forming curved patterns from the north to south pole. The filings are most dense near the poles where the field is strongest.
Field lines emerge from the north pole and enter at the south pole.
Lines are closest together near the poles (strongest field).
Lines never cross each other.
The Science Behind Magnetic Field Lines
Magnetic field lines reveal the structure and strength of magnetic fields:
- Field lines emerge from the north pole and terminate at the south pole.
- The density of lines indicates field strength (more lines = stronger field).
- Iron filings become tiny magnets (dipoles) that align with the field.
- Field lines never cross - each represents the path a north pole would follow.
- Inside the magnet, field lines run from south to north, completing the loop.
The magnetic field B around a bar magnet can be modeled as a dipole field:
B = (μ₀/4π) [ (3r(m·r)/r⁵) - (m/r³) ]
Where:
μ₀ = permeability of free space
m = magnetic moment vector
r = position vector from the dipole
