Graphite, an allotrope of carbon, is a moderately good conductor of electricity. As a result, pencil lead, which is composed of powered graphite and clay, may be used to introduce, extend, and amplify concepts pertaining to electric circuits and resistance.1
What follows are laboratory activities and demonstrations relating to electric circuits and resistance that can be performed using pencil lead as a conductor. I've collected this material from several sources and only take credit for sharing it with the reader.
Activities developed by Dr. Lawrence Woolf involving circuits drawn with pencil lead may be employed to quantitatively determine 1) how the length and width of a conductor affect electrical resistance, and 2) the result of combining conductors in series and parallel.2 ( Note: For best results when creating circuits, use a graphite drawing pencil rather than a standard #2 pencil. High-content graphite pencils such as a 6B work...