Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538
Demonstrations are cataloged according to PIRA Bibliography
PLEASE REQUEST DEMOS WELL IN ADVANCE
Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.
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You have selected the following Demos:
video - Superconducting Wire
Purpose:Show the resistance of a superconductor vanishes below the critical temperature. Tc = 90K for YBCO.
This demo utilizes a short length of high temperature superconducting (HTS) wire, which is actually shaped like a ribbon with Yttrium Barium Copper Oxide (YBCO) sandwiched between two layers of stainless steel. Tc = 90K. For example, STI describes some of the different superconducting wires.
Connect power supply to black and red leads. Connect the other two leads to the microvoltmeter.
Turn ON the power supply and adjust the current until 1/2 A flows through the wire. The room temperature voltage will measure just under 2mV.
Have students watch the reading on the voltmeter while the LN2 is poured into the Styrofoam container. After a few seconds, the voltage drop across the wire will fall to zero.
Hints:Must use a power supply that can control current: