5H40.25 - Dancing Slinky

Code Number:
5H40.25
Demo Title:
Dancing Slinky
Condition:
Excellent
Principle:
Coil "pinch", attractive forces on current carrying coils
Area of Study:
Electricity & Magnetism
Equipment:
Car battery, 40 amp power supply, overhead slinky apparatus.
Procedure:

Place the slinky apparatus on the overhead projector.  Connect on wire from the battery to the coil.  As you touch the other wire from the battery to the other end of the coil you will see the individual coils "pinch" together in one spot.  This demonstrates that current flowing in the wire loops of a coil create an attractive force that pulls the loops closer together if they are not fixed in place.

References:
  • "Current Coil (OHP)", Southern California Physics Technician Asscociation, SCPTA
  • Hector Maciel, Maria Salazar, Anatol Hoemke, Doug Johnson, "The Electric Slinky", 2007 AAPT Apparatus Competition.

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.