Electric Field Visualiser
Place charges and watch electric field lines and equipotentials form in real time.
Conservative Vector Fields 🖖
Electric fields are the negative gradient of a scalar potential field...
Making an invisible push visible 🖖
This tool turns something you cannot see — the electric influence around a charge — into a picture. Each line traces the path a tiny positive test charge would be pushed: away from positive charges, toward negative ones. The single most useful habit is to read the spacing. Where lines crowd together the field is strong; where they spread apart it is weak. Line density is force made graphic.
Why you can't trap a charge in mid-air 🖖
Place two like charges and a null point appears between them where the field is exactly zero. It looks like a resting spot — but it is a saddle, not a bowl: nudge a test charge and it escapes. Earnshaw's theorem (1842) proves that no fixed arrangement of charges can hold another charge in stable static equilibrium. The same maths forbids levitating a magnet with magnets alone — you always need spin, diamagnetism, or active control.
Example problems
- Single + - Single +
- Dipole - Dipole
- Two + - Two +
- Quadrupole - Quadrupole