5E50.30 - Thermoelectric Magnet

Code Number:
5E50.30
Demo Title:
Thermoelectric Magnet
Condition:
Good
Principle:
Thermocouple and Electromagnets
Area of Study:
Thermoelectricity
Equipment:
Thermoelectric loop, electromagnet iron core with plate, liquid nitrogen, Bunsen burner or propane torch, masses.
Procedure:

NOTE: This demo will take about 10 minutes to do with the propane torch running the whole time and making noise.  To minimize the time you can hang paper clips from the magnet instead of waiting for it to be able to attract and hold the 500 gram plate.

Secure the loop into the iron core with the set screws.  Place one end of the loop into liquid nitrogen for a few minutes.  Then, heat the other end with the propane torch.  After several minutes the electromagnet should be working well enough to  attach the plate and then hang a 1 kg mass off of it.

The following table gives the elements in the thermoelectric series in order:

  • Silicon
  • Bismuth
  • Nickel
  • Cobalt
  • Palladium
  • Platinum
  • Uranium
  • Copper
  • Manganese
  • Titanium
  • Mercury
  • Lead
  • Tin
  • Chromium
  • Molybdenum
  • Rhodinium
  • Iridium
  • Gold
  • Silver
  • Aluminium
  • Zinc
  • Tungsten
  • Cadmium
  • Iron
  • Arsenic
  • Tellurium
  • Germanium

Taken from The Thermoelectric Series

References:
  • E - 340:  "Thermoelec. Magnet & Solar Cubs",  DICK and RAE Physics Demo Notebook.
  • H-374:  "Thermocouple Magnet - Seebeck",  DICK and RAE Physics Demo Notebook.
  • Stanislaw Bednarek, "Thermoelectric Motor", AJP, Vol. 63, #11, Nov. 1995, p. 1051.
  • Adolf Cortel, "Thermoelectric Generators", Physics Education, Vol. 42, # 1, Jan. 2007.
  • R. W. Pohl, "Metals as Conductors of the First Class.  Thermo-electric Pressures", Physical Principles of Electricity and Magnetism, p. 268.
  • Various e-mail correspondence with Adolf Cortel.


Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.