Currents and Magnetic Fields in Hollow Tubes: An In-Class Experiment and Lab Demonstrator for EMC Education

This paper describes a very successful demonstration experiment developed for a course on electromagnetic compatibility at Masters' level at the Eindhoven University of Technology. Such demonstrator plays a big role in teaching both practical concepts and theoretical skills relevant for the topics on cabling, grounding and shielding. The success of the demonstrator relies on several factors, among which: its simplicity, its versatility, its possibility to confront measurements with actual field calculations and on the astonishing fact that these effects occur at 50 Hz. The demonstrator evidences current and magnetic field distributions in a hollow iron tube, for different connection configurations. Some key principles are evidenced, among others: skin effect, proximity effect and the principle of the path of least impedance.