Using the formula \(\vec F=I\vec L\times\vec B\), we see that the
magnetic field and the current run in the same direction along the
right edge, and run in opposite directions on the left edge, so the
cross product on the sides is zero. The magnetic field is
perpendicular to the current along the top and bottom edges, whose
length is \(W\), so the force those edges feel is \(\abs{\vec
F}=IWB\). Using the right-hand rule, we find the following forces:
Notice that the forces all cancel, so the net force is zero. But
something
will happen to this loop, which we'll discuss in
the next section.