Find the current that flows in a silicon bar of 10-µm length having a 5-µm x 4-µm cross section and having free electron and hole densities of 105 / cm³ and 1015 / cm³, respectively, when a 1 V is applied end-to-end. Use µn = 1200 cm²/V·s and µp = 500 cm²/V·s.