A 90 wt% Cu–10 wt% Ni alloy is known to have an electrical resistivity of 1.90 × 10–7 Ω•m...

A 90 wt% Cu–10 wt% Ni alloy is known to have an electrical resistivity of 1.90 × 10–7 Ω•m at room temperature (25°C). Calculate the composition of a copper–nickel alloy that gives a room-temperature resistivity of 2.5 × 10–7 Ω•m. The room-temperature resistivity of pure copper may be determined from the data in Table 18.1; assume that copper and nickel form a solid solution.

Table 18.1 Room-Temperature Electrical Conductivities for Nine Common Metals and Alloys