Charge Garden
Arrange a few charges. Discover the shape of an invisible field.
Click empty space to place · drag any charge to move · right-click / Delete to remove · R over the field rotates the next dipole
Select charges with the keyboard
Select a listed charge, then use the arrow keys to move it. Change Strength to resize its charge. Tab reaches the sign and remove controls.
Description
A two-dimensional window into the electric field of stationary point charges. Warm circles are positive; blue circles are negative. A dipole is a pair of equal, opposite charges. Place several and see how their fields combine.
Instructions
- Choose Positive, Negative, or Dipole, then click empty space. Strength sets the magnitude of new charges and changes the selected charge.
- Drag charges to reshape the field. Click a charge to select it, flip its sign, or remove it. Dipole members move independently.
- Compare one charge, two equal signs, and an opposite-sign pair. Try making a square with alternating signs. Undo restores your last edit; Clear empties the field.
Arrowheads show the direction a small positive test charge would initially be pushed. They are field directions, not particle trajectories. Lines start on positive charges and end on negative charges or continue beyond the view; negative-only fields enter from outside.
Model: the in-plane slice of the ordinary three-dimensional Coulomb field, E = Σ q r / |r|³, in relative units. These are point charges held in place, not infinite charged wires. Field lines are numerically traced with finite seeds; their displayed density is illustrative, not a calibrated flux measurement. The finite circles hide the point-charge singularities. Charges cannot overlap. Up to 16 charges; layouts save automatically in this browser when storage is available.
Background: OpenStax: electric field lines. For a moving charge and finite-speed propagation, try Electromagnetic Field.