Particles & Fields

Electromagnetic Fields

Arrange charges, turn on a current, and discover how changing fields carry energy.

See the field between charges

Electric field · XY plane

Drag a charge or the white probe. Field lines point in the direction a positive test charge accelerates.

At the probe

Experiment state

Change the conditions

Selected chargeCharge +1.0 nC

Position X · m

Position Y · m

Potential colors and contours

Test charge sign

Up to six sources. Moving sources recomputes a static field instantly; this view does not model radiation.

Field lines Direction arrows

Move the probe precisely

Probe X · m

Probe Y · m

Try this

Compare a dipole with two like charges, then release a test charge from the white probe.

What you are seeing

Equations & model notes