How to measure the current-voltage characteristics of Ohmic conductors and superconductors

Abstract

A comparison between two different techniques useful to measure the current-voltage (I-V) characteristics of conducting materials or devices will be presented, suitable for an undergraduate laboratory devoted to the electrical measurements. First, I-V curves of linear resistors with known nominal resistance are measured by using the simplest version of a DC method and an AC method, in order to settle the experimental procedure. Then, nonlinear I-V curves of a superconductor are measured with the same procedures at different temperatures down to 77K.