Electric Currents & Ohm’s Law – Units of Resistivity example 2

Question : An aluminium wire 7.5 m long is connected in a parallel with a copper wire 6 m long. When a current of 5 A is passed through the combination, it is found that the current in the aluminium wire is 3 A. The diameter of the aluminium wire is 1 mm. Determine the diameter of the copper wire. Resistivity of copper is 0.017 μΩ-m; that of the aluminium is 0.028 μΩ-m.