An npn silicon transistor is biased in the inverse-active mode with VBE 3 V and VBC 0.6 V. The doping concentrations are NE 1018 cm3 , NB 1017 cm3 , and NC 1016 cm3 . Other parameters are xB 1 m, E0 B0 C0 2 107 s, DE 10 cm2 /s, DB 20 cm2 /s, DC 15 cm2 /s, and A 103 cm2 . (a) Calculate and plot the minority carrier distribution in the device. (b) Calculate the collector and emitter currents. (Neglect geometry factors and assume the recombination factor is unity.)

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.

An air conditioning system consist of a 5 cm diameter pipe, operating at a pressure of 200 kpa. the air initially enters the pipe at 15°c with a velocity of 20 m/s and relative humidity of 80%. if the heat supply throughout the process is 960 w, determine the relative humidity and the temperature at the outlet

Atmospheric air has a temperature (dry bulb) of 80° f and a wet bulb temperature of 60° f when the barometric pressure is 14.696 psia. determine the specific humidity, grains/lb dry air. a. 11.4 c. 55.8 d. 22.5 b. 44.1