This simulation illustrates the electric field generated
by a charged ring, and shows how, by the principle of
superposition, a continuous charge distribution can
be thought of as the sum of many discrete charge elements
(in this case, thirty). 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 ring (given
by the large resultant vector, and by the large two
dimensional field map). By moving the observation point
around with the arrow keys, changes in field magnitude
and direction can be observed at different positions
relative to the ring.
Note that along the axis of the ring, the perpendicular
component of each element's field is cancelled out by
the corresponding element directly opposite it on the
other side of the ring. The resultant field is thus
described only by the contributions along that axis.
At the center of the ring, where those components are
zero, the resultant field is also exactly zero.