2. Given that the Nordheim coefficient for Cu in Au at 20°C is, C = 450 n2 m; electrical resistivity of gold at 0°C is 22.8 n2 m; and the temperature coefficient of resistivity at 0°C is 1/251 K¹, (a) what are the electrical resistivity of gold at 20°C, (b) the maximum atomic percentage and (c) corresponding weight percentage of Cu that can be added to pure Au without exceeding a resistivity that is twice that of pure gold at 20°C? (1 n = 10-992).

Fig: 1