AMT General Electricity Practice Exam 2026 – Full Study Resource

Resistance depends on how easily charges can move through the material, which is set by the material’s resistivity, plus the conductor’s geometry. The relationship is R = ρ L / A, so longer pieces have more resistance, larger cross‑sectional area lowers resistance, and higher resistivity raises resistance. Temperature affects resistivity—for most metals, raising temperature increases resistivity and thus resistance. The color of the insulation doesn’t affect resistance, since insulation is nonconductive and doesn’t change the path for current.