The resistance value of fly ash per unit area and unit thickness is often expressed by its resistivity, and the unit is Ω/cm. The resistance when each of the length and cross-sectional area is 1 unit is the specific resistance. That is, the resistance value when the length of the wire is 1 cm and the cross-sectional area is 1cm2, expressed in ρ, and the unit is Ω·cm. https://www.ste-mart.com/f...