Generally speaking, the resistance of a conductor is proportional to the length of the conductor, but the conductivity of a conductor is mainly related to the conductivity. Brass is copper-zinc alloy, and copper is pure copper. The less alloying elements the copper contains, the better the conductivity.
1. The ability of an object to conduct current is called conductivity. The conductivity of various metals is different. Generally, silver has the best conductivity, followed by copper and gold. Solid conduction refers to the long-distance migration of electrons or ions in solids under the action of electric field. Usually, a type of charge carrier is dominant, such as: electronic conductor, which is dominated by electronic carriers; ionic conduction, which is dominated by ionic carriers; mixed conductor, which has both carrier electrons and ions. In addition, some electrical phenomena are not caused by carrier migration, but by solid polarization induced by electric field, such as dielectric phenomena and dielectric materials.
2. Electrical conductivity of objects. Generally speaking, metals, semiconductors, electrolyte solutions or molten electrolytes and some non-metals can conduct electricity. The conductivity of non-electrolyte objects is determined by the number of free electrons in the outer layer of atoms and their crystal structure. If metal contains a large number of free electrons, it is easy to conduct electricity, while most non-metals are not easy to conduct because of the small number of free electrons. Graphite conducts electricity while diamond does not, which is the reason of crystal structure. Electrolyte conducts electricity because anions and cations are produced when ionic compounds dissolve or melt.