Final answer:
The correct expression for the volume charge density of a solid sphere is ρ = Q / (4/3 * π * r³), where Q is the total charge and r is the radius of the solid sphere.
Step-by-step explanation:
The correct expression for the volume charge density ρ of a solid sphere is option B) ρ = Q / (4/3 * π * r³), where Q is the total charge and r is the radius of the solid sphere.
The volume of a sphere is given by V = 4/3 * π * r³. Since the charge density is defined as the ratio of the charge to the volume, we have ρ = Q / V. Substituting the expression for the volume of a sphere, we get ρ = Q / (4/3 * π * r³).