Further Experiments

on MHD

and the like...

Lorentz Force in liquid metals

The Lorentz force is here illustrated with two MHD experiments using liquid Gallinstan. In the first one, a horizontal current is applied and the bottom of the tank is paved with an array of magnets; in the second one, an array of probes apply alternate polarities, while the tank is immerged in a vertical applied magnetic field (This movie was realized thanks to Johann Herault. Experimental credit: Stéphan Fauve's group).

A very simplified motor

A very simple motor, using only a battery, a small cylindrical magnet, a wire and a screw. At the contact point between the wire and the magnet, the current goes toward the axis of symmetry (going through the screw), the field there is vertical and the resulting lorentz force is therefore azimuthal.

Emmanuel Dormy