Clicking on the different links below will produce different magnetic fields in the box above.
The wires (perpendicular to the screen) or coils (in and out of the screen) are not visible, but
you can determine what they are from the field. You can also click on a point to read off the
magnetic field at that place. What combination gives rise to the observed fields?
Physlet problem authored by Scott Bonham, NCSU.