(a) A wire sample (1mm in diameter by 1 m in length) of an aluminum alloy (containing 1.2% Mn) is placed in an electrical circuit. A voltage drop of 432 mV is measured across the length of the wire as it carries a 10 A current. (i) Determine the resistivity of this alloy (ii) If the length of this alloy is increased to 1.5 m, predict the new resistivity. Justify your answer. (b) Table Q6(b) represents the room temperature conductivities for several common metals. Based on Table Q6(b), answer the following questions: (i) Discuss conduction of metals in terms of the resistivity and the reciprocal of conductivity. (ii) Why most metals are extremely good conductors of electricity as compared to other materials such as ceramic and polymer. Room-Temperature Electrical Conductivities for Nine Common Metals and Alloys Metal Silver Copper Gold Aluminum Brass (70Cu-30Zn) Iron Platinum Plain carbon steel Stainless steel Electrical Conductivity |(92-m) 6.8 X 10? 6.0 x 10? 4.3 x 107 3.8 x 10? 1.6 x 10 1.0 x 10 0.94 x 107 0.6 x 10 0.2 x 10