Conductor, Electrical. a material that readily permits the passage of an electric current through it—that is, a material that has a high electrical conductivity, or low resistivity ρ.Good conductors are materials with ρ ≤ 10 -6 ohm-cm.In contrast to conductors, insulators have high resistivities—from about 10 14 to 10 22 ohm-cm.onductor, Electrical. a material that readily permits the passage of an electric current through it—that is, a material that has a high electrical conductivity, or low resistivity ρ.