(a) the fermi energy in silicon is 0.30 ev below the conduction band energy ec at t 300 k. plot the probability of a state being occupied by an electron in the conduction band over the range ec e ec 2kt. (b) the fermi energy in silicon is 0.25 ev above the valence band energy ev. plot the probability of a state being empty by an electron in the valence band over the range ev 2kt ev e ev.

At steady state, air at 200 kpa, 325 k, and mass flow rate of 0.5 kg/s enters an insulated duct having differing inlet and exit cross-sectional areas. the inlet cross-sectional area is 6 cm2. at the duct exit, the pressure of the air is 100 kpa and the velocity is 250 m/s. neglecting potential energy effects and modeling air as an 1.008 kj/kg k, determine ideal gas with constant cp = (a) the velocity of the air at the inlet, in m/s. (b) the temperature of the air at the exit, in k. (c) the exit cross-sectional area, in cm2