Electric field
Place positive and negative charges on the canvas and watch electric field lines and equipotential contours emerge in real time. Drag charges to rearrange them. The field strength is encoded as color intensity — brighter near the charges, fading with distance.
E = kQ/r² V = kQ/r k = 8.99 × 10⁹ N·m²/C²
Coulomb's law and the electric field
Every electric charge creates an electric field that extends through all of space. The field at any point is the force a unit positive test charge would experience there. For a point charge Q, the field strength falls off as 1/r² — Coulomb’s inverse-square law, the electrical analog of gravity.
Field lines
Field lines are curves tangent to the electric field at every point. They begin on positive charges and end on negative charges (or extend to infinity). The density of lines indicates field strength. Field lines never cross — if they did, the field would point in two directions at once.
Equipotential contours
Equipotential lines connect points of equal electric potential. They are always perpendicular to the field lines. No work is done moving a charge along an equipotential. Near a single charge, equipotentials are concentric circles; between multiple charges, they deform into complex shapes that reveal the geometry of the field.
Superposition
The total field from multiple charges is the vector sum of each individual field — the superposition principle. This is why you can drag charges around and watch the entire field pattern reconfigure instantly.