Derive an expression relating the intrinsic level E, to the center of the band gap Eg/2. Calculate the displacement of £, from Eg/2 for Si at 300 K, assum- ing the effective mass values for electrons and holes are l. lw0 and 0.56/M0> respectively.

Air enters a horizontal, constant-diameter heating duct operating at steady state at 290 k, 1 bar, with a volumetric flow rate of 0.25 m°/s, and exits at 325 k, 0.95 bar. the flow area is 0.04 m2. assuming the ideal gas model with k = 1.4 for the air, determine (a) the velocity at the inlet and exit, each in m/s, and (c) the rate of heat transfer, in kw flow rate, in kg/s, (b) the mass kg 0.3