Generally, the most ideal conductor is made of which material?

• A. Aluminum
• B. Copper
• C. Iron
• D. Plastic

Answer: (B)

The key factor is how easily electrons can move through the material, i.e., the material’s electrical conductivity (or its resistivity). Copper has a very low resistivity, about 1.68×10^-8 Ω·m at room temperature, which means it offers very little resistance to current for a given cross-section. That low resistance leads to minimal heat losses and efficient current flow, making copper the best practical conductor among the options. Aluminum is lighter and cheaper but has higher resistivity, so it isn’t as good a conductor per same size. Iron conducts much less efficiently, and plastic is an insulator with very high resistivity. For these reasons, copper is the ideal choice for conducting electricity.