1. If the current density passing through the n-type 1 ohm-cm Si bar is increased to 104 A/cm2 and 105 A/cm2 (by reducing the cross-sectional area, what are the drift times for an electron across a 1 mm long Si bar?
2. The mobility of electrons in a certain n-type Si is about 1000cm2V-s. What is the scattering mean-free-time of the electrons/ (mn=m).