5H40.25 - Dancing Slinky

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

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.

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

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