Northwestern Physics Demos                                 Go back to ELECTRICITY   
DCS# 5F20.51NWU#  E-26Location:    8 F 4
title: Lamp Board
Circuit Lights

Lamps can be arranged in various series and parallel circuits and the effective resistance can be seen in the current flow and the brightness of the first bulb.  A voltmeter can measure the total voltage in to calculate power use or the voltage over individual bulbs.  It is useful to show that the voltage over an unscrewed bulb in series with others is equal to the line voltage, which explains how the shunt design functions in holiday lights.
Each switch can have 3 positions, up, down, neither.

Which switches should be opened or closed to produce the largest resistance?
Which will produce the lowest?

pix of set upcircuit