Consider a silicon p-n step junction (or abrupt junction) at room temperature. if the doping concentrations are na = 10^17 cm^-3 and nd = 10^14 cm^-3 , what is the depletion width (also known as space charge width)? also find the maximum electric field (e0). then derive the expression for the electric field e(x), and the potential field v(x). do not use limits of integration. to find the constant of integration, use boundary conditions such as "e=e0 at x=0". once you get expressions for e(x), you can use that for v(x). use boundary conditions, "at x=-xp0, v(x)=0, and at x=xn0, v(x)=v0".

If the thermal strain developed in polyimide film during deposition is given as 0.0044. assume room temperature is kept at 17.3 c, and thermal coefficient of expansion for the film and the substrate are 54 x 10^-6c^-1 and 3.3 x 10^-6c^-1respectively. calculate the deposition temperature.

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