Consider a single crystal of copper (FCC) and a single crystal of zinc (HCP). The cubic structure is isotropic with respect to electrical conductivity while the hexagonal single crystal is anisotropic, i.e. the electrical properties of the material differ within the basal plane compared to along the c-axis of the crystal (electrical properties along a = b but = c). Starting with Tds = -dq where q is the charge density, which is a conserved quantity so that dq/dt =-V.J 1) Using an argument based on entropy production, for copper what can be concluded about the algebraic sign of the electrical conductivity? 2) What is the relationship between the gradient in the electrical potential and the flux of the charge density?