A section of 14-gauge aluminum wire is used to carry current in an electronic device. The resistivity ρ of aluminum at various temperatures is provided in the table below.
Temperature (°C)
Resistivity ρ (×10−8Ωm)
20
2.65
60
3.50
100
4.36
(a) Calculate the conductivity σ of the aluminum wire at 20 °C and at 100 °C.
(b) Determine the percent decrease in conductivity of the wire as the temperature rises from 20 °C to 100 °C.
(c) Using the metallic bonding model, explain why raising the temperature of a metal generally leads to the trend observed in part (b).