5K20.40 - Eddy Current Levitator - Spinning Disk

Code Number:
5K20.40
Demo Title:
Eddy Current Levitator - Spinning Disk
Condition:
Excellent
Principle:
Eddy Currents
Area of Study:
Electricity & Magnetism
Equipment:
Neodymium magnets, Round 1/4 inch thick copper plate, Pasco rotator, turntable, flexible arm.
Procedure:

Place the round copper plate on the rotator or turntable.  Adjust the magnet on the flexible arm so that it is toward the outer portion of the plate.  Turn on the rotator or turntable and observe the magnet rise and levitate above the plate.

References:
  • Carlos Saraiva, "An Inexpensive Apparatus for Demonstrating Magnetic Levitation", TPT, Vol. 45, #5, May 2007, p. 311.
  • Thomas D. Rossing, John R. Hull, "Magnetic Levitation", TPT, Vol. 29, #9, Dec. 1991, p. 552.
  • Harry H. Kemp, "Lenz's Law", TPT, Vol. 15, # 9, Dec. 1977, p. 543.
  • W. M. Saslow, "Electromechanical Implications of Faraday's Law: A Problem Collection", AJP, Vol. 55, #11, Nov. 1987, p. 986.  In particular see p. 991 of this article.   
  • B-290, "Motor Disk-Levitated & Stalled", DICK and RAE Physics Demo Notebook.
  • James Luxon, "An Eddy Current Demonstration", Apparatus Notes July 1965-December 1972, p. 44.
  • James D. Livingston. "Up With Magnets!". Driving Force - The Natural Magic of Magnets. p. 157.

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.