5G20.47 - Amperes Ants

Code Number:
Demo Title:
Amperes Ants
Magnetic Domains
Area of Study:
Electricity & Magnetism
Iron Filings, Rotating Motor and Magnet Unit, Plexiglas Plate with attached Petri Dish, Power Supply.

Center the Petri dish with the iron filings over the rotating magnets.  Run the power supply at 6 or 7 volts which should give the magnets a slow rotation rate.  The iron filings will clump together in long strands, stand up when the magnet is below them, and march in the opposite direction of the rotating magnets.  

  • R. C. Nicklin, J. G. Lindsay, Jr., T. L. Rokoske, "Amperes Ants", AJP, Vol. 43, #1, Jan. 1975, p. 111.
  • H. Richard Crane, "How Things Work - Mini-Motors Driven by Waves", TPT, Vol. 32, #6, Sept. 1994, p. 360.

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