Hall Effect

—A phenomenon first observed by E. H. Hall in 1879, of a transverse electromotive force produced when a powerful magnet is caused to act upon a current flowing in a strip of very thin metal. A ume a steady current to flow through this thin metal strip, and let two points, transversal to the line of flow, be connected to a galvanometer. These points of contact can be adjusted until there is no deflection, showing that they are in the same equipotential line. If the strip of metal be placed in a strong magnetic field at right angles to the lines of force, a deflection of the galvanometer is produced, which indicates that an alternation takes place on the stream lines of current in the strip. The effect is said to be due to the deflections of the moving carriers of the current or electrons.