A Study in Photoelectricity

A. A theoretical current-voltage relation, for the case of retarding potentials applied to a photoelectric cell, was derived for each of the three cases of plane-parallel, spherical and cylindrical electrodes. When these curves were compared with experimental ones obtained from a sodium cell having spherical electrodes, it was found that the agreement was very poor. The data, treated by the extrapolation method, gave values of Planck's constant in good agreement with that of Birge, thus seeming to show that the theory here developed, rather than the data, is at fault. B. A test of a new photoelectric effect, described by E. Marx, was investigated and the conclusion reached that no such effect exists in well-constructed cells.