In the visual
, you can observe the effect of the magnetic
field on a straight cable. If the conductor is curved, or if the field
is not homogeneous, then it is necessary to imagine the conductor is
composed of an infinite number of small straight fragments of length dL
and
add up (integrate) the forces acting on each and every one of
them.
The direction of the force
is given by the left hand rule: if the index finger points in the
direction of the field and the middle finger in the direction of the
current, then the thumb will point in the direction of the force.