A pure germanium crystal has a resistivity of 0.60 Ω•m and 2.5 × 10¹³ electrons/cm³ at 20 °C. i) Determine the mean free time for germanium at this temperature. ii) The mean free time for germanium is greater than the mean free time for some conducting materials. Give a reason for the high resistivity of germanium relative to conductors.

Consider a copper wire segmented into two different sections, labeled 1 and 2. Both sections, although of different diameters, carry the same constant current of 8.0 A. Determine the drift velocity of the electron in each section. The number density of electrons in copper is 8.5 × 10²⁸ m^-3.

Find the time required for two moles of electrons to pass through a cross-section of a 1.4 mm diameter silver wire, given that the electron drift speed within the wire is 4.2 × 10^-4 m/s. The number density of electrons in silver is 5.86 × 10²⁸ m^-3.

In a silver wire, the average time interval between collisions for electrons is 12ps. If the intensity of the electric field is 42 mV/m, determine the speed at which the electron drift.