Having shown the forces that result from a given magnetic field, we must now
complete the picture of magnetic forces and fields by describing the source of
those fields. Such a topic is complex, as magnetic fields come from sundry
sources. Magnets, compasses, straight wires, curved wires, and solenoids are
just some of the sources we will study. Such diverse sources give rise to
complex phenomena, only explainable through vector calculus and difficult
mathematics. This SparkNote will try to cover most sources on a basic level, but
also provide the necessary mathematics to provide for a complete understanding
of the topic.

We begin by describing magnets.
Though they are easily describable in terms of north and south poles, their
magnetic fields are actually quite complicated, and are not examined on a
quantitative basis. In the same section, we move on to perhaps the simplest
source of a magnetic field, a straight wire. From this point we must develop
some calculus regarding magnetic fields
before analyzing more complex phenomena. Equipped with this mathematics, we can
then examine the fields of rings, coils, and
solenoids.

By the end of this SparkNote, one should have a fairly complete understanding of
magnetic phenomena. We will have described both the cause and effect of magnetic
fields. With this complete understanding we can then examine magnetism on a
theoretical basis, using
vector calculus as our guide.