Abstract
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 77 K.