Aluminum is trivalent with atomic weight 27 and density 2.7 g/cm3, while the mean collision time between electrons is 4 × 10−14s. Calculate the current flowing through an aluminum wire 20 m long and 2mm2 cross-sectional area when a potential of 3 V is applied to its ends.
where n is the number of electrons per m3, No being Avagardro’* number, A the atomic weight and d the density, the factor 3 is for the trivalency.
