// electrostatics · F = kQ₁Q₂/r²

Electric Field

Click the canvas to place a charge — drag charges to move them

Click the canvas to place charges and see field lines form

Study the charge configuration, then calculate the answer below.

About Electric Field

  1. Placing charges. Select + or − from the toolbar, then click on the canvas. Each click places a charge at that position.
  2. Moving charges. Switch to Move mode (or just drag any charge) to reposition them. Field lines update in real time.
  3. Dipole shortcut. Click Dipole to place a +/− pair side by side — a quick way to see the classic dipole field pattern.
  4. Field lines. Lines flow from positive to negative charges. The density of lines indicates field strength.
  5. Charge info. The side panel shows the list of charges and the net force on the selected charge.
  6. Practice mode. Switch to Practice for randomly generated Coulomb's law and field strength problems.
Tip: Place two positive charges near each other to see how like charges repel — the field lines curve away from each other!