Resistance in a Wire

Explore how length, area, and material affect resistance

Resistance depends on the material's resistivity ρ (intrinsic property), wire length L, and cross-sectional area A: R = ρL/A. Longer wire = more resistance (more collisions). Thicker wire = less resistance (more paths for electrons). Resistivity varies by material (copper: 1.7×10⁻⁸ Ω·m; nichrome: 100×10⁻⁸ Ω·m) and increases with temperature for metals. This explains why heating elements use nichrome wire.