Notice that there are fundamental differences between the electric force and
magnetic force on a charge. First, a magnetic force acts on a charge only if the
charge is moving; the electric force acts on a charge whether it moves or not.
Second, the direction of the magnetic force is always perpendicular to the magnetic
field, while the electric force is always parallel (or antiparallel) to the electric
field.
An Easy Way to Eliminate Answers
Most questions on magnetism
have answers with a
direction in them. Simply
knowing the direction
that the magnetic force
is pointing and then using
the right-hand rule will
usually help you cancel
out two to three
answer choices.The SI unit for the magnetic field is the tesla (abbreviated T), which is one newton
per ampere-meter. Another common unit for magnetic field strength is the gauss