A constant electric field, E=12 V/cm, exists in the +x direction of an n-type gallium arsenide semiconductor for . The total current density is constant and is equal to 100 A/cm2. At x=0, the drift and diffusion current densities are equal. Let T=300 K and fn=8000 cm2/V-s. (a) Determine the expression for electron concentration n(x). (b) Calculate the electron concentration at x=0 and at x=50 fm