Resistance, electrical

The opposition of an object to the passage of an electric current.

An object with a uniform cross section has a resistance proportional to its resistivity and its length, and inversely proportional to its cross-sectional area. The SI unit of resistance is the ohm (Ω).

Controlled-source electromagnetic surveying is based on the resistivity contrast between relatively conductive sedimentary rocks saturated with saline water and relatively resistive hydrocarbon saturated rocks.