Magnetic Fields is a free interactive simulation of the magnetic field
patterns around permanent magnets for GCSE Physics (Edexcel IGCSE 4PH1).
Students use a plotting compass to map magnetic field lines around single, attracting,
and repelling magnet configurations, investigating how the field pattern changes between
them. This is a required practical for Edexcel IGCSE 4PH1. No login required — includes
a worksheet and self-marking quiz.
A magnetic field is invisible — but a plotting compass can reveal it. Can you map the
field around a bar magnet?
Aim: To investigate the shape of the magnetic field around different
magnet configurations using a plotting compass.
Advanced: Global magnet strength
Global strength
This slider multiplies each magnet's base strength. 0 = off, 1 = normal, 5 = five times
stronger.
Choose a magnet configuration from the buttons above
Drag the plotting compass around the simulation area
Drag the compass to a position and click to mark where the needle points. Repeat across the whole area to build up a map of readings
Once you've plotted enough points, click 'Draw Field Lines' and connect your points into smooth curved lines.
Click the drawing button again to exit drawing mode
Use "Clear All" to start over with a clean canvas
For each configuration: sketch your completed field pattern on your worksheet. Mark the direction of field lines with arrows — field lines always run from North to South outside the magnet.
Compare your attracting and repelling field patterns. Where are the field lines closest together? What does this tell you about field strength in those regions?