Linie pola elektrycznego

Consider the two-dimensional projection of a positive point charge's electric field. The vectors point away, and their magnitudes decrease with distance.

For a dipole, this field distribution becomes challenging to visualize. For a large number of charges, it becomes intractable.

An alternative visualization via electric field lines solves this problem.

They are defined as lines with direction, such that at any point, the tangent to the electric field line gives the direction of the electric field.

The magnitude of the electric field is given by the density of the electric field lines, the number of field lines per unit cross-sectional area perpendicular to the field.

This representation does not require tracing the lengths of the vector arrows but still traces the electric field at any point uniquely.

For example, the electric field lines of a dipole indicate that the field points away from the positive charge and into the negative charge.

If the magnitude of the positive charge is larger than the negative charge, the field lines become denser near the former.