The semiconductor is a homogeneous, p-type material in thermal equilibrium for t ≤ 0. The excess minority carrier lifetime is 10^-6 ns. At t = 0, an external source is turned on which produces excess carriers uniformly at rate of g'=1020 cm^-3s^-1. At t = 2*10^-6 s , the external source is turned off.

(a) Derive the expression for the excess-electron concentration as a function of time for 0 ≤ t ≤[infinity].

(b) Determine the value of excess electron concentration at (i) t = 0, (ii) t = 2*10^-6 s , (iii) t = 3*10^-6 s and (iv) t = [infinity].

(c) Plot the excess electron concentration as a function of time.

Agas contained within a piston-cylinder assembly e end nation about same energy states, 1 and 2, where pi 10 bar, v undergoes two processes, a and b, between the sam 0.1 m3, ui-400 kj and p2 1 bar, v2 1.0 m2, u2 200 kj: process a: process from 1 to 2 during which the pressure- volume relation is pv constant process b: constant-volume process from state 1 to a pressure of 2 bar, followed by a linear pressure-volume process to +20 0 state 2 kinetic and potential energy effects can be ignored. for each of the processes a and b, (a) sketch the process on p-v coordinates, (b) evaluate the work, in kj, and (c) evaluate process the heat transfer, in kj