lowresistance

Low resistance refers to an electrical path or component that offers a small opposition to the flow of electric current. The resistance R of a conductor is defined by Ohm's law as R = ρL/A, where ρ is the material resistivity, L is length, and A is cross-sectional area. A low resistance path allows higher current for a given voltage, and is common in power wiring and connectors. However, very low resistance can pose safety risks if it creates a short circuit, causing excessive current and overheating.

Contributors and variation: Materials with low resistivity (such as copper and aluminum) and thick cross-sections reduce R. Temperature increases resistivity in most conductors; contact resistance at joints and interfaces adds to the total path resistance. Measurement is done with an ohmmeter on de-energized circuits; for more precise values, four-wire (Kelvin) methods minimize lead resistance. Aging, corrosion, and mechanical damage can raise effective resistance.

Applications and implications: In power systems, low resistance minimizes I^2R losses and improves efficiency; low-resistance interconnections, bus bars, and low-resistance shunts support high current. In electronics, designers balance low resistance against reliability, heat, and noise; extremely low resistance paths can also obscure fault conditions if not properly managed.

Related concepts include Ohm's law, resistivity, impedance, and contact resistance.