The resistance of a uniform conductor increases with length and decreases with cross-sectional area.
Difficulty
Beginner
Read time
5 min
Prerequisites
Basic algebra and consistent SI units
Source
OpenStax, College Physics 2e, §20.3 (Paul Peter Urone and Roger Hinrichs)Textbook reference retained from the OpenFormulaGraph dataset; adaptation credits and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted the notation, explanations, assumptions, and topic placement, and expanded the numerical check into a worked example.
The resistance of a uniform conductor increases with length and decreases with cross-sectional area. Electrical resistivity is a material property that depends on temperature; its symbol is distinct here from fluid mass density.
| Symbol | Meaning | Units |
|---|---|---|
| Conductor resistance | ||
| Electrical resistivity | ||
| Conductor length | ||
| Cross-sectional area |
Compare resistance for different conductor dimensions.
Compare conductors with different resistivities.
A uniform wire has resistivity 1.68 × 10⁻⁸ Ω·m, length 10.0 m, and cross-sectional area 0.000100 m². Find its resistance.
Textbook reference retained from the OpenFormulaGraph dataset; adaptation credits and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted the notation, explanations, assumptions, and topic placement, and expanded the numerical check into a worked example.
Assumptions
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