Department: EEE

1. The electron drift mobility in silver has been measured to be 56 cm2 V-1 s-1 at 27 °C. The atomic mass and density of Ag are given as 107.87 amu or g mol-1 and 10.50 g cm-3, respectively.

a. Assuming that each Ag atom contributes one conduction electron, calculate the resistivity of Ag at 27 °C. Compare this value with the measured value of 1.6 × 10-8 ? m at the same temperature and suggest reasons for the difference.

b. Calculate the thermal conductivity of silver at 27 °C and at 0 °C

2. Consider a very thin long plate of Aluminum of length L = 20 mm, width W = 2 mm, thickness D = 0.05 mm, carrying a current of 200 mA, if placed in a magnetic field of flux density B = 0.16 T and hall voltage 34 nV. The current flows along the length L and the magnetic field is along thickness D. Determine the Hall coefficient for Al and the atomic concentration for the plate. Why is the hall is voltage ‘small’? How can you increase this voltage? [Given, atomic mass for Al as 27×10-3 kg/mole and density 2.7×103 kg/m3] [10]