Equations
Resistance of a wire
Electricity and magnetism · id resistivity
R = \frac{\rho L}{A}
| Symbol | Quantity | Unit | Meaning | Usual range |
|---|---|---|---|---|
R | resistance | ohm | Resistance of the wire | 0.001 to 1e+09 |
rho | resistivity | ohm*m | Resistivity of the material | 1e-09 to 1e+16 |
L | wire length | m | Length of the wire | 0.0001 to 1e+06 |
A | cross-sectional area | m^2 | Cross-sectional area of the wire | 1e-12 to 1 |
Assumptions
- Uniform wire
- Constant temperature
Valid when
- No extra conditions.
Found by
Questions with these words retrieve this equation: resistivity, wire, resistance, copper, length, gauge, thickness.
Source
OpenStax University Physics Volume 2, Chapter 9 (reference; entry written by the project). License: MIT. Entry confidence: 0.99.