It is easier to measure the electrical resistivity of a metal than to measure its thermal conductivity. A new alloy has an electrical resistivity \(ho_{e}\) of \(55 \mu \Omega \mathrm{cm}\). Use the Wiedemann-Franz relationship, plotted on Fig. 3.10, to estimate its thermal conductivity, \(\lambda\).

Fig. 3.10

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1012 1016 1020 10-8 1000 10-4 Electrical resistivity, pe (2 m) T-Conductivity - resistivity 104 108 Metals Cu alloys, Boron carbide Silicon SIC Al alloys, Tungsten carbide 100 10 Zn alloys- Walloys Mg alloys Steels Lead alloys - Stainless steels Ti alloys Thermal conductivity, (W/m K) 10 Line of = Cipe Diamond Al nitride SigNa Al2O3 Stone CFRP Leather Natural materials Concrete Polymers & elastomers Cork Wood- Butyl rubber ZrO2 Soda glass PET PA. of Glass ceramic Technical ceramics Glasses Silica glass GFRP PE 0.01 Rigid polymer foams Foams PS PMMA Neoprene Flexible polymer foams 104 MFA, 15 108 1012 1016 1020 Electrical resistivity, P (u2 cm) 1024 1028