Circular Wire Resistance
Circular Wire Resistance Model
DC resistance of a circular wire is:
Units: Ohms
AC resistance of a circular wire is:
Units: Ohms
Skin Depth is:
Units: meters
Description
Resistance calculated using this tool includes both dc and ac resistance of a circular wire. At low frequencies, where skin depth is greater than wire radius, ac resistance is approximately the same as the dc resistance. As frequency increases, ac resistance increases.
Assumptions and Limitations
Dimensions are in meters.
Wire is assumed to have uniform circular cross section over its length.
Wire relative permeability: 
Wire relative conductivity: 
Constants
Permeability of free space: 
H/m
Conductivity of copper: 
= 5.98 x 10 7 S/m (Siemens per meter) at 20-degrees C
Reference: “Analysis of Multiconductor Transmission Lines,” 2nd Ed., Clayton R. Paul, 2008.
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