This HTML 5 app demonstrates the Lorentz force, exerted on a current-carrying conductor swing in the magnetic field of a horseshoe magnet.
You can switch on (off) the current by using the upper button ("On / Off"). The other two buttons ("Reverse current" and "Turn magnet") make it possible to change the direction of the current respectively of the magnetic field. If the corresponding checkboxes are selected, the app will indicate the conventional direction of current (red arrows), the magnetic field lines (blue) and the Lorentz force (black arrow).