Exploring electrical properties of superconductors using four-lead resistance measurements.
Yes – with some effort
In a series of experiments designed for year 13 physics and/or tertiary students we explore the drop in resistance to zero at the critical temperature. We sometimes show students how to automate the measurement in a programming language called LabVIEW.
NCEA & Science Curriculum
PHYS 1.3, PHYS 2.6
The superconductor is immersed in sand after connection to a power supply and a voltmeter set up for four-lead resistance measurements. A thermocouple is used to measure temperature. The apparatus is cooled with liquid nitrogen and warms slowly while students take data. See Detailed Instructions for more information.
If you do not have training and confidence in the use of liquid nitrogen, contact a university physics or chemistry department for help. In any case, follow the usual liquid nitrogen precautions including goggles. In addition, a high ratio of demonstrators to students is strongly recommended.
Individual teachers are responsible for safety in their own classes. Even familiar demonstrations should be practised and safety-checked by individual teachers before they are used in a classroom.
Floating on Air
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