An A.C. Method of Measuring Resistance

Some applications of an alternating field method to various problems of superconductivity are described. It is shown how the method can be used to measure the resistance and self inductance of a metal ring, and this was applied to show how the resistance of a superconducting tin ring is restored by a magnetic field. The method is also convenient for a rapid determination of the order of magnitude of the specific resistance of a substance, and to see whether or not it becomes superconducting; several elements were examined in this way, but no new superconductors were found.