| | 104 | |
| | 105 | * Exercise: Measure the resistance of pencil lead (graphite) |
| | 106 | * Use a pencil to draw a thick dark line on a piece of paper. Go over the same line many times until it is thick and has a lot of graphite. |
| | 107 | * Turn your multimeter on and the range selector to Ohms (often shown with the Greek letter Omega) |
| | 108 | * Plug the black wire into the hole labeled COM |
| | 109 | * Plug the red wire into the hole labeled V/mA/Ohms... |
| | 110 | * Touch the black probe to one end of the black line on the paper |
| | 111 | * Touch the red probe to the other end of the black line on the paper |
| | 112 | * Observe the resistance measurement on the multimeter display |
| | 113 | * Move the probes closer together and observe how the resistance changes |
| | 114 | |
| | 115 | * What happened: all substances present some resistance to the flow of electrons; graphite presents a moderate level of resistance. The more graphite the electrons must pass through, the higher the resistance. |
