Straight Wire
A single current-carrying wire produces concentric circular field lines — the canonical Biot-Savart law demonstration.
2D
NGSS HS-PS2-5
AP Physics C
IB Physics 5.4
Simulations
Twenty interactive magnetic-field simulations, organized by topic and mapped to NGSS, AP Physics C, and IB Physics standards. Click Open to run a simulation in the browser, or Copy embed to drop it into a Canvas, Blackboard, Schoology, Moodle, or Notion page.
Magnetic fields of currents
From a single straight wire to toroidal coils — the geometries that define Biot-Savart and Ampère's law.
Single Current Loop
A single circular loop of current — the building block for understanding solenoids, Helmholtz pairs, and toroids.
3D
NGSS HS-PS2-5
AP Physics C
IB Physics 5.4
Antiparallel Wires
Two long straight wires carrying equal currents in opposite directions. The field lines show the repulsive interaction pattern.
2D
NGSS HS-PS2-5
AP Physics C
IB Physics 5.4
Parallel Wires (Same Direction)
Two wires carrying currents in the same direction — field lines wrap both wires together and the wires attract.
2D
NGSS HS-PS2-5
AP Physics C
IB Physics 5.4
Helmholtz Coils
Two coaxial current loops spaced one radius apart produce a highly uniform magnetic field between them.
3D
AP Physics C
IB Physics 5.4
Solenoid (LIC View)
A long solenoid. Linear Integral Convolution visualization reveals the near-uniform internal field and weak external field.
2D
NGSS HS-PS2-5
AP Physics C
IB Physics 5.4
Solenoid (3D View)
The same solenoid rendered in 3D with traced field lines — rotate to see how the internal field aligns with the axis.
3D
NGSS HS-PS2-5
AP Physics C
IB Physics 5.4
Toroidal Coil
Eight current loops arranged around a ring form a toroid. The field is almost entirely confined inside the torus, circling the major axis.
3D
AP Physics C
IB Physics 5.4
Permanent magnets
Bar magnets, paired dipoles, and gap geometries — the patterns students compare to current loops to build dipole intuition.
Bar Magnet Dipole
A single ferrite bar magnet. Iron-filings visualization reveals the classic dipole field pattern from N to S poles.
2D
NGSS HS-PS2-4
AP Physics C
IB Physics 5.4
Two Magnets Attracting
Two collinear bar magnets with opposite poles facing each other — field lines flow continuously between them.
2D
NGSS HS-PS2-4
IB Physics 5.4
Two Magnets Repelling
Two collinear bar magnets with like poles facing each other — field lines bulge outward and the magnets repel.
2D
NGSS HS-PS2-4
IB Physics 5.4
Horseshoe Magnet Gap
Two flat magnets with N and S poles facing across a small gap — approximately uniform field in the gap, like a classroom horseshoe magnet.
2D
NGSS HS-PS2-4
IB Physics 5.4
Aligned Magnet Pair
Two parallel bar magnets magnetized in the same direction — their dipole fields superpose into a stronger composite field.
2D
NGSS HS-PS2-4
IB Physics 5.4
Charged particles in fields
The Lorentz force F = qv × B in action — circular orbits, mass spectrometry, helical motion, and right-hand-rule deflection.
Cyclotron Motion
A charged particle launched into a uniform magnetic field traces a circular (cyclotron) orbit — the basis of mass spectrometry.
2D
AP Physics C
IB Physics 5.4
Mass Spectrometer
Two particles with the same speed but different charge-to-mass ratios trace different orbit radii — the principle behind magnetic-sector mass spectrometry.
2D
AP Physics C
IB Physics 5.4
Helical Motion
A charged particle with velocity components both parallel and perpendicular to the magnetic field traces a 3D helix.
3D
AP Physics C
IB Physics 5.4
Cyclotron Radius vs Speed
Three particles with identical charge-to-mass ratio but different speeds trace orbits of different radii — visceral demonstration that r ∝ v.
2D
AP Physics C
IB Physics 5.4
Lorentz Deflection
A charged particle entering a uniform magnetic field is deflected by the Lorentz force F = qv × B — direct visualization of the right-hand rule.
2D
AP Physics C
IB Physics 5.4
Field visualization techniques
Same physics, different rendering — a side-by-side teaching tool for comparing iron-filings to LIC.
Earth and applications
Real-world geometries that students recognize before they learn the physics.
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