Electric Charges and Fields — Part 2: Field lines and the electric dipole: visual lesson, ISC Class 12 Physics

Lesson

Field lines and dipoles

Part 2 — drawing fields with lines, and the simplest charge arrangement that appears everywhere in chemistry and physics: the dipole.

In this lesson you will

Traced numerically; arrowheads checked against the computed field.

Concept

An electric line of force is a curve whose tangent at every point gives the direction of $\vec E$ there.

Lines start on positive charges and end on negative charges (or at infinity).
Two lines never intersect: at a crossing the field would have two directions at once.
Lines are closer together where the field is stronger.
Electrostatic field lines never form closed loops, and they meet a conductor’s surface at right angles.

Traced numerically from Coulomb’s law.

Diagram

Standard patterns:

Isolated positive charge: radial lines outward; negative charge: radial lines inward.
Two oppositely charged parallel plates: straight, parallel, equally spaced lines between them — a uniform field — with some bending (fringing) at the edges.