5D10.40 Resistance Model


Flow of electrons through a conductor, resistance


This model simulates the flow of electrons through a conductor as well as the resistance experienced by the electrons. When electrons flow through a conducting medium, they will run into a complex lattice of atoms and thus they are not moving in a straight line. In this model, ping pong balls navigating through an arrangement of nails represent free electrons moving past atoms in a conductor.



  • [1] Board with an arrangement of nails
  • [4] Ping pong ball
  • [4] Small foam ball


  1. Lean the board against the wall.
  2. Let the ping pong balls or foam balls roll down from the top.
  3. As the balls roll down, point out they are slowed by collisons with the "atoms".


Additional Resources


  • PIRA 5D10.40


  • Don't attempt this at home!

Last revised

  • 2018


Related AV

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If you have any questions about the demos or notes you would like to add to this page, contact Ricky Chu at ricky_chu AT sfu DOT ca.