Question

1. Find the cheapest conductor based on the cost to meet a specified maximum resistance per length of conductor. The cost for a fixed resistance per length is proportional to pdens PresC. Copper Aluminum Density pdens (Mg/m3) 8.90 2.70 7.14 Resistivity Pres Price C (2m) ($/b) 1.67x10-8 2.83 2.67x10-8 0.81 5.96x10-8 1.09 | Zinc 2. At what price per pound would sodium make an even cheaper conductor comparing with the one you get for the above problem? Sodium has a density of 0.967 Mg/m3 and a resistivity of 4.96 x10-8 m.

Answer 1

o soli Cost of fixed Resistance per leyth & Soden & Sarana C. for copper Sam = 2.90 mg fres=1.678163 sm m3 (= 2.83 & leb Cost = Sana frusa C. = 8.90 x 1.67x10-822.83 TE = 4.206410-7 for aluminium Iden = 2.70 mg Im3 Ires=2.67*10-8 rm .C=0.81 $10 Cost = Idena bresxC = 2.70*2.67*108 x 0.81 Cost = 5.839410-8

for zinc Idm = 7.14 mg , fres= 5.96410-8 C=1109 till Cost = I den & rusac = 7.14 x 596x 108 x 1.09 = 4.638x10- + out of three aluminuim is cheap conductor on the based of cost 7 a 5.839 x 10 Aluminuim cost for fixed resistance le a the of aboue. cruent we have to compare cost problem with sodium. Soduim I den = 0.967 mg/m3 Pres= 4.964108 rm ,(=) Cost = Schena Sresa c.. 5,839 x 10-8 = 0.967 x 4.96*108xC I c=1.21 41 lb