Electric Field Visualizer

What this visualizer does

Each source charge contributes an electric field vector and an electric potential. The page superposes those contributions in real time, making it possible to see where fields reinforce, cancel or curve between charges.

Coulomb's lawSuperpositionField vectorsField linesEquipotentialElectric potential

Choose a field configurationor add and drag charges manually

Field controls

Selected source charge

Charge 1 · +2.00 nC

Source charge +2.00 nC

Negative values reverse the field direction. Zero removes the source contribution without deleting the marker.

x position m

y position m

Visualization layers

Vector density 14 × 9

Field-line density 14 seeds / charge

Test probe

Probe charge +1.00 nC

The probe does not alter the source field. Its force is F⃗ = qE⃗: positive follows E⃗, negative reverses, zero gives F = 0, and arrow length is log-scaled to |qE|.

The probe is extremely close to a point charge. The ideal point-charge field diverges as r → 0, so the on-screen vector length is capped for readability.

Probe & selected-charge results

Interactive electric field map

Drag any colored charge to move it. Click a charge to select it, or drag the white probe crosshair to inspect the local field. The physical model domain is 2.0 m (6.56 ft) wide.

Coulomb + superposition

drag charges · drag probe · probe force arrow = qE · orange +V · blue −V · dashed 0 V

How to read the field

No single layer tells the whole story. The visualizer deliberately combines three complementary representations.

01 / Field vectorsArrow direction gives E⃗ direction; arrow intensity/length is scaled logarithmically so weak and strong regions remain visible.

02 / Field linesLines are tangent to E⃗. They leave positive charges and terminate on negative charges or at the model boundary.

03 / EquipotentialsAlong an equipotential line, V is constant. Electric field is perpendicular to equipotential contours.

04 / ProbeThe movable probe reports local E⃗ and V, then multiplies E⃗ by the chosen probe charge to show force.

Model assumptions & limits

This is an electrostatic point-charge model. It is intended for conceptual learning and preliminary checks, not high-voltage insulation design or detailed electrostatic simulation.

Background & FAQ

Why do field lines never cross? +

Why can electric field be zero while electric potential is not zero? +

What is special about the midpoint of equal like charges? +

What happens at the midpoint of an equal electric dipole? +

Are the field-line particles actual electrons? +

Can I use this for conductor shapes or high-voltage clearances? +

CALCULATION NOTE // source-field calculations use SI units internally and convert only at the input/display boundary.