The influences of temperature and impurities on resistivity of metals are given, in standard symbols, by:...

Transcribed Image Text:

The influences of temperature and impurities on resistivity of metals are given, in standard symbols, by: Pi=po + a.T, the temperature 7 to be in °C. Pi- A c; (1-ci) (a) (b) Using the data provided in Fig. Q4, determine: (i) The values of p, and a for pure copper (Cu): (ii) The values of A for nickel (Ni) as an impurity in copper; and (iii) The electrical resistivity of copper containing 1.75% Ni at 100°C. 5 A Electrical resistivity (10-82-m) m N 1 0 -250 -200 Cu + 3.32 at % Ni -150 Cu + 2.16 at% Ni Deformed Put Pi P₂ -100 Cu + 1.12 at% Ni "Pure" copper Temperature (°C) Fig. Q4 -50 0 +50 (12 marks) Phosphorus is added to high-purity silicon to give a concentration of 102 m² of charge carriers at room temperature. Calculate the room-temperature conductivity of this material, assuming electron and hole mobilities are 0.14 and 0.048 m²/V-s respectively. (8 marks) (Total: 20 marks) The influences of temperature and impurities on resistivity of metals are given, in standard symbols, by: Pi=po + a.T, the temperature 7 to be in °C. Pi- A c; (1-ci) (a) (b) Using the data provided in Fig. Q4, determine: (i) The values of p, and a for pure copper (Cu): (ii) The values of A for nickel (Ni) as an impurity in copper; and (iii) The electrical resistivity of copper containing 1.75% Ni at 100°C. 5 A Electrical resistivity (10-82-m) m N 1 0 -250 -200 Cu + 3.32 at % Ni -150 Cu + 2.16 at% Ni Deformed Put Pi P₂ -100 Cu + 1.12 at% Ni "Pure" copper Temperature (°C) Fig. Q4 -50 0 +50 (12 marks) Phosphorus is added to high-purity silicon to give a concentration of 102 m² of charge carriers at room temperature. Calculate the room-temperature conductivity of this material, assuming electron and hole mobilities are 0.14 and 0.048 m²/V-s respectively. (8 marks) (Total: 20 marks)