5B10.40-Electric Field Lines on overhead

Description: This demonstration visually shows the electric field lines using the overhead projector.


  • 5 Electrode Configurations
  • Top container of oil and wood chips
  • Overhead Projector (OHP)
  • (Optional) Long Grounding wire
  • Nakamura electrostatic field apparatus , for OHP
  • Piezoe4lectric charge source or static genecon power source

Setup Procedure:

  1. Include all configurations unless otherwise asked.
  2. Place on the overhead and focus.
  3. If possible, connect the grounding wire to a grounded terminal. Make sure it’s a ground terminal and not a -V terminal (both are black).

Demonstration Procedure:

  1. Insert container of oil and chips(green substance) into lower chamber of electrostatic field apparatus. Be sure to shake up too evenly distribute the oil and chips throughout the container, and orient as to place the air bubble in the smaller chamber of the container.
  2. Select preferred electrode configuration and place in upper chamber of electrostatic field apparatus. Place with electrodes facing down and with the contact points of the electrode touching the contact points of the terminals
  3. Using either the piezoelectric charge source or static genecon power source, induce a current through the electrodes.
    a)If you are using the piezoelectric charge source, attach the grounding wire too ground and insert the point of the piezo into the red terminal. Click the piezo several times to induce current.
    b)If you are using the static genecon power source, attach ground to ground and positive to positive, then spin handle to generate a current.
  4. Observe how the oil and wood chip solution orients to the electric field lines
  5. Repeat with the other three electrode plates. Shake up the oil container to remove the previous pattern.Be sure to shake up solution before switching the diodes to remove previous pattern

Note: As with most electrostatic demonstrations, this works best under 50% humidity.