In the attached figure, a coil is wrapped around the central arm of a flat H-shaped thin plate. DC current flows through the coil and magnetizes the arm. At the same time, DC current also flows from another source through the plate as shown in the figure. Within the central arm, the directions of flow of the magnetic field and current are perpendicular to each other.
If B is the magnetic flux density, L is the length along which the current I flows through the arm, does the plate experience a force F according to the equation F = B I L ?