Question

27.) Power transmission lines are made from a core material and a material forming sleeve around the core. Which functions do those two materials fulfil? To minimise the number of necessary utility poles, the materials should create as little sag in the line as possible. Using the two charts below, pick suitable candidates for the sleeve and core materials. Explain your selection. (5 marks) Page 8 of 11 Mid-year Examinations, 2018 PROD111-18S1 (C) 10000 Metals Technical ceramics Ni ys Spba CERP Ti alloys Z0 SN Boron carbido Aallys Al nride 1000 AlDs Glasses GFRP Skaglss Sids Brae FC FA Phencc Soda doss 100 Mays In as Sicon Wood Strone Cu aloy PS ЕMMA Leather 10 - Tad aka FPIFE PP Nooprono Polymers and. elastomers Natural/ materials Cork 0.1 polgr foams Fabe polym oms Foams Strength-Resistivity MA 01 0.01 103 106 109 1012 1015 1018 1021 1024 1028 Electrical resistivity, Pe (ucm) Strength dy or dl (MPa) 10 000 Ceramics SigN Strength-Density Ti alloys Steels Al203 Metals Composites Sic Ni alloys Al alloys CFRP Metals and polymers: yield strength Ceramics and glasses: MOR Elastomers: tensile tear strength Composites: tensile failure Tungsten alloys 1000 Polymers and elastomers Mg alloys. Tungsten carbide GFRP PEEK PA PC PММА PET, Copper alloys 100 Woods, . Natural materials PP PE 10 Rigid polymer foams Woods. L Zinc alloys Lead alloys Foams Concrete Butyl Silicone rubbet elastomers Cork 0.1 Flexible polymer foams MFA. 07 0,01 0.01 0.1 10 Density, p (Mg/m3) Strength, a, or el (MPa)

Answer 1

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