Explanation of Icon
The icon shows the topology of the magnetic field lines of a wire carrying
current out of the page, in a background
magnetic
field that vanishes for x < 0 and points upwards and is constant
for x > 0. This is one frame of a two-dimensional animation showing the forces
on a current carrying wire in a background magnetic field, as
explained in the example in the
main text.
![[contents]](contents.gif)