The Line Segment

Most of the time, we use Gauss’ law to calculate the electric field around an infinite line of charge. However, this method only works because we can take advantage of the symmetry of the infinite line. If we want to find the electric field around a charged line segment, we cannot simplify Gauss’ law very easily because there are components of the electric field perpendicular and parallel to the line of charge.

In times like this, it is actually easier to go back to the continuous form for Coulomb’s law. In the video above, I derive the expression for the electric field around a line of charge.