SUBJECT: Integrating Around a Ring of Current

DESCRIPTION: This simulation illustrates the magnetic field generated by a ring of current, and shows how, by the principle of superposition, a continuous current distribution can be thought of as the sum of many discrete current elements (in this case, thirty). Each element generates its own field, described by the Biot-Savart 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 ring (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 ring), and the total field changes accordingly. As the entire ring is integrated, the components of the field contributions in the plane of the ring are cancelled out, leaving a total field that is perpendicular to the ring on its central axis.

VISUALIZATION: Fullscreen Version