, where ρ is the specific resistance, l is the length and A is the cross-sectional area of the conductor. Now, when l=1 and A=1,R=ρ So specific resistance or resistivity of a material may be defined as the resistance of a specimen of the material having unit length and unit cross-section. Hence, specific resistance is a property of a material and it will increase with the increase of temperature, but will not vary with the dimensions (length, cross-section) of the conductor.