5F20.55 • Circuit Analysis: Series/Parallel Resistors

Location: Cabinet 2

Photo of the Demonstration Used at the University of Texas at Austin.

Instructions / Notes:

• This basic set-up of different circuit boards simply shows how adding an additional resistor in a series - or - parallel circuit affects current flow.
• Note: the now difficult to source Chinese projection ammeters have at a minimum a 15% error factors.
• Each circuits box is powered from a 0 to 5 volt power supply - which needs to be set to 3 volts.
• The series circuit box, 5F10.10, comes with three *10 ohm* resistors in series.
• The parallel circuit box, , comes with three *25 ohm* resistors in parallel and a very wonky ammeter.
• The above circuit boxes were made to fit an old-school overhead projector.
• The circuit boxes have toggle switches to add or remove the second and third resistors to the circuit.
• Demo Staff: Leave the toggle switches in the open position when setting up the demo.
• Also, we alway start with the series box when setting up the demo - Be sure to place the parallel box of to the side.

The Photo Below shows only the Parallel Circuit Box resting on a A/V projector.

Last updated on June 8, 2026