Resistivity:

Resistivity is described as the measure of the resistance a material imposes on current flow.  A resistance of a provided length of conductor depends upon the resistivity of which material, the length of the conductor and the cross-sectional area of the conductor, according to Equation (2-1).

R  =   ρL/ A                                           (2-1)

where

R = resistance of conductor,

ρ = denotes for specific resistance or resistivity cm- ? /ft

L = length of conductor, ft

A = cross-sectional area of conductor, cm

The resistivity ρ (rho) permits various materials to be compared for resistance, according to their nature without regard to length or area.  The higher the value of, the higher the resistance.

Table 1 provides resistivity values for metals having the standard wire size of one foot in length and a cross-sectional area of 1 cm.