Q.
The resistivity of aluminium is 2.834×10−8Ω m. Thus,
conductance across a piece of aluminium wire, that is 4.0 mm in diameter and 2.00 m long is (assume current =1.25 A)
Radius =24.0=2.0mm=2×10−3m;l=2m
Area of cross section and resistance (R) is related to the resistivity as,
(Specific resistance), the length and area by
R = Resistivity ×AreaLength =π(2.0×10−3m)22.834×10−8Ωm×2.00m =4.5×10−3Ω
Conductance =R1=45×10−31=222Ω−1(S)