The resistivity of a semiconductor can be modified by adding different amounts of impurities. A rod of semi-conducting material of length L and cross-sectional area A lies along the x-axis between x = 0 and x = L. The material obeys Ohm’s law, and its resistivity varies along the rod according to rho(x)=rho0exp(−x/L). The end of the rod at x = 0 is at a potential V0 greater than the end at x = L. (a) Find the total resistance of the rod and the current in the rod. (b) Find the electric-field magnitude E(x) in the rod as a function of x. (c) Find the electric potential V(x) in the rod as a function of x. (d) Graph the functions rho(x), E(x), and V(x) for values of x between x = 0 and x = L.