5B50.10 • Equipotential Lines

Location: Cabinet 2

Photo Shows Apparatus used by the University of Texas at Austin.

Concepts Conveyed:

• Equipotential lines are lines that have the same potential difference. These lines are perpendicular to electric field lines and can be used to find the electric field lines indirectly.

Instructions / Notes:

• Attach a black conductive sheet with the electric paint lines to the cork board using the plastic push pins.
• Push one metal push pin, completely, into the center of each electric paint line (they can be a bit difficult to make out). Make sure that the pin does not go through any of the pre-existing holes of the corkboard.
• Use wire 3 (blue wire) to connect the negative terminal of the battery holder to the left metal push pin.
• Use wire 1 to connect the COM terminal of the multimeter to the negative terminal of the battery holder as well.
• Turn the multimeter on and place the dial on 20 DCV.
• Plug wire 2 into the terminal ABOVE the COM terminal. The other end will be used to find the potential at different points on the conductive sheet.
• Use wire 4 to connect the positive terminal of the battery holder to the right metal push pin.
• Test the circuit by making the end of wire 2 touch the two metal push pins. The positive pin should have a voltage of around 1.6V, as that is the voltage of the cell, and the negative terminal should have a voltage of exactly 0V.
• Make sure to hold the pin perpendicular to the sheet and do not move your hand. If the multimeter keeps fluctuating, make sure that the alligator clip is not loose on the banana plug.

Demo Staff:

• New shapes can be made using the electric paint. It requires 24 hours to dry.

Last updated on June 5, 2026