SUBJECT: Integrating Along a Line of Charge
DESCRIPTION: This simulation illustrates the electric field generated by a line of charge, and shows how, by the principle of superposition, a continuous charge distribution can be thought of as the sum of many discrete charge elements. Each element generates its own field, described by Coulomb's Law (and represented here by the small vectors attached to the observation point), which, when added to the contribution from all the other elements, results in the total field of the line (given by the large resultant vector). In this animation, each element is being added up one by one (indicated by the highlighted portion of the line), and the total field changes accordingly. As the entire line is integrated, the components of the field contributions in the direction of the line are cancelled out, leaving a total field that is perpendicular to the ring on its perpendicular bisector. If this were truly an infinite line of charge, the total field of the line would be perpendicular to the line at all points.
VISUALIZATION: Fullscreen Version