Resistance is a physical property of materials. If a material has a high resistance, it opposes the passage of a steady electric current. The lower the resistance, the easier it is to force electrons to leave atoms and move through the material. Metals, by nature, have a low resistance. That’s why metals like copper are used as electrical conductors. Rubber, wood, and plastics, on the other hand, have a high resistance. That means it's nearly impossible to force their electrons to leave their atoms. A plastic coating around wire acts as an insulator, preventing the flow of electricity. Use the slider control to increase or decrease current.