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Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538


Physics Demo Manual

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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 Electrostatics
 Electric Fields And Potential
 Capacitance
 Current and Resistance
 Electromotive Force And Current
 DC Circuits
 Magnetic Materials
 Barkhausen Effect
 Electromagnet
 Diamagnetic Levitation
  video  - Hysteresis
 Curie Point
 Meissner Effect (diamagnetic levitation)
 Magnetism
 Inductance
 Induction
 Complex Circuits
 Semiconductors And Tubes
 Transmission Lines and Antennas

Curie Point

Purpose:

To demonstrate the loss of magnetic properties of iron upon heating.

Procedure:

We have two setup options, of which the first one is more visually stimulating:

1. A coil of iron wire is attached to a thin copper wire. Allow the iron wire to "levitate" in the field of the magnet. Use a bunsen burner to heat the iron wire and watch it drop away when the curie point is reached.

2. Hang the small magnets on the bottom of the Curie point apparatus' iron studs. The iron studs are actually soldering iron tips, each labeled 5, 6, 7, 8 representing a different curie point (see Weller Soldering Iron Info below). Connect the apparatus to a Variac and run about 10A current to heat up the studs. After the iron tips heat up their respective curie point temperature, they will loose magnetic property and the magnets will fall down. Each iron tip will reach their curie point after a few minutes: 1-2 min for tip#5, 3-4 min for tip#6, 6-7 min for tip#7, long time for tip#8.

Hints:

Regular precautions with high current demos. Crank the Variac slowly not to blow the fuses, watch for overheating wires.