Ohm's Second Law

This law describes the quantities that influence the electrical resistance of a conductor, as cited in its statement:

The resistance of a homogeneous conductor of constant cross section is proportional to its length and the nature of the material of its construction, and is inversely proportional to the area of ​​its cross section. In some materials it also depends on your temperature.

Being expressed by:


ρ = resistivity, depends on the conductor material and its temperature.

ℓ = conductor width

A = cross-sectional area.

Since the electrical resistance unit is ohm (Ω), then the unit adopted by SI for resistivity is .