A coaxial conductor has radii a = 0.8 mm and b = 3 mm and a polystyrene dielectric for which ∈r = 2.56. If P = (2/ρ)a_ρ nC/m² in the dielectric, find

(a) D and E as functions of ρ;

(b) V_ab and χ_e.

(c) If there are 4×10¹⁹ molecules per cubic meter in the dielectric, find p(ρ).