All Tools

Electric Field Visualizer

Place positive and negative point charges on a 2D canvas and watch the electric field come to life. Field arrows show direction and strength, field lines trace the paths, and clicking any point reveals the net field and potential with full vector superposition math.

Electric Field Canvas

Click to add charges. Drag to reposition. Click a charge to select it.

++5 \u03BCC−-5 \u03BCC

Controls

1 μC10 μC
+5 μC at (200, 200)
-5 μC at (400, 200)

Field at Point

Click anywhere on the canvas to see the electric field and potential at that point.

Step-by-Step Calculation

Click a point on the canvas to see the vector superposition calculation.

Reference Guide

Coulomb's Law

The electric field at a distance rr from a point charge QQ is given by Coulomb's law.

E=kQr2E = \frac{kQ}{r^2}

where k=8.99×109  N⋅m2/C2k = 8.99 \times 10^9\;\text{N}\cdot\text{m}^2/\text{C}^2 is Coulomb's constant. The field points radially outward from positive charges and inward toward negative charges.

Superposition Principle

The net electric field at any point is the vector sum of the fields from each individual charge. This is the principle of superposition.

E⃗net=∑i=1nE⃗i=∑i=1nkqiri2r^i\vec{E}_{\text{net}} = \sum_{i=1}^{n} \vec{E}_i = \sum_{i=1}^{n} \frac{kq_i}{r_i^2}\hat{r}_i

Each field vector has both magnitude and direction. You must add the x-components and y-components separately, then combine them to find the net field.

Electric Potential

Electric potential is a scalar quantity (not a vector). It represents the electric potential energy per unit charge at a point in space.

V=∑i=1nkqiriV = \sum_{i=1}^{n} \frac{kq_i}{r_i}

Because potential is a scalar, you simply add the values from each charge. Positive charges create positive potential, negative charges create negative potential.

Electric Field Lines

Field lines are a visual tool for mapping the electric field. They start on positive charges and end on negative charges (or extend to infinity).

The density of field lines indicates field strength. Closer lines mean a stronger field. Field lines never cross each other. The tangent to a field line at any point gives the direction of the electric field there.