Download Calculation of Wire Resistance

Resistance of a Wire
R
l
A
R is the resistance (in Ohms, Ω)
 is a property of the material called resistivity
L is the length of the material (in cm)
A is the cross-sectional area of the material
(in cm2)
What are the units of ρ ?
EGR 101
1
Calculation of Resistance
Example
Calculate the resistance of a 25 cm length of
copper that has a cross-sectional area of
0.04 cm2.

l
6
R    1.723 X 10 Ω  cm
A

 25cm 

2 
 0.04cm 
3
 1.08 X 10 Ω  1.08mΩ
EGR 101
2