Physics 111 Advanced Laboratory. Professor Sumner Davis This video accompanies the Hall Effect In A Plasma Experiment, providing students with an introduction to the theory, apparatus, and procedures. The Hall effect is the phenomenon of a voltage developing across two boundaries in a direction transverse to the current flow in a system of charged particles in a magnetic field owing to the Lorentz force q(v x B). In this experiment you will measure the Hall voltage as a function of current, magnetic field strength, and gas pressure in a gaseous discharge tube. These data are then used to determine the density and mean speed of free electrons in the system. This experiment requires a review of electricity and magnetism, thermal physics, and atomic physics. It is also an excellent introduction to plasma physics http://advancedlab.org