Conductors and insulators
Some materials let current through easily and some almost stop it. You measure copper, aluminum, rubber, and skin with a meter, then change the wire's length, thickness, and heat.
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What to try
- 1Start on Copper, then pick Rubber. Rubber is an insulator, so the meter reads OL.
- 2Pick Dry skin, then Wet skin. Wet skin has far less resistance, so it lets much more current through.
- 3Pick Copper and set Length to 1,000 ft. Twice the length gives twice the resistance. Then set Thickness to 8 AWG and watch it fall.
NEC 2026 sections it covers
- 310.5(A)
- The smallest aluminum wire size is 12 AWG.
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