Device physicsMVP
Resistor (R = ρL/A)
Resistance of a uniform conductor from its resistivity, length, and cross-sectional area.
Inputs
Result
Enter values and calculate to see the result.
Interpretation
Enter the resistivity, length, and cross-sectional area.
Formula
R = ρ · L / A
Uniform conductor.
Variables
| Symbol | Variable | Unit |
|---|---|---|
| R | Resistance | Ω |
| ρ | Resistivity | Ω·m |
| L | Length | m |
| A | Cross-section area | m² |
Assumptions & validity
This tool assumes:
- Uniform conductor; ignores temperature dependence and contact resistance.
Worked example
ρ = 1.7×10⁻⁸ Ω·m (copper), L = 1 mm, A = 1 µm².
R = 1.7e-8 × 1e-3 / 1e-12 ≈ 17 Ω