Final answer:
The drift speed of conduction electrons in an iron wire carrying a current can be calculated using electron charge and number density, the cross-sectional area of the wire, and the current flowing through it.
Step-by-step explanation:
To determine the drift speed of conduction electrons in an iron wire with a cross-sectional area of 1.50×10⁻⁵ m² carrying a current of 20.0 A, we can use the formula I = nqAvd, where I is the current, n is the number density of electrons, q is the charge of an electron, A is the cross-sectional area, and vd is the drift velocity. The charge of an electron is q = 1.60 × 10⁻¹⁹ C. Given the atomic mass of iron and using Avogadro's number, one can calculate the number of atoms per mole of iron and consequently the number of free electrons available for conduction. Using the density of the material together with its molar mass allows the determination of the number density of electrons, n. With n, A, and q known, the drift velocity vd can be computed from the current.