Abstract: A stress-strain test for conductors. A test assembly receives first and second conductive layers and a dielectric layer adjacent each of the conductive layers. The layers are generally ring-shaped and concentric when received by the test assembly and the dielectric layer separates the conductive layers from each other. A magnetic field source provides a magnetic field to the test assembly and a variable current source provides current to the second conductive layer. A circuit measures a change in capacitance between the conductive layers when the current in the second conductive layer is varied whereby the stress and strain characteristics of the second conductive layer are determined as a function of the capacitance change.