Ohm's law

related topics
{math, energy, light}
{system, computer, user}
{acid, form, water}
{theory, work, human}
{war, force, army}
{math, number, function}
{film, series, show}
{son, year, death}
{work, book, publish}

Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference or voltage across the two points, and inversely proportional to the resistance between them.[1]

The mathematical equation that describes this relationship is:[2]

where I is the current through the resistance in units of amperes, V is the potential difference measured across the resistance in units of volts, and R is the resistance of the conductor in units of ohms. More specifically, Ohm's law states that the R in this relation is constant, independent of the current.[3]

The law was named after the German physicist Georg Ohm, who, in a treatise published in 1827, described measurements of applied voltage and current through simple electrical circuits containing various lengths of wire. He presented a slightly more complex equation than the one above (see History section below) to explain his experimental results. The above equation is the modern form of Ohm's law.

In physics, the term Ohm's law is also used to refer to various generalizations of the law originally formulated by Ohm. The simplest example of this is:

where J is the current density at a given location in a resistive material, E is the electric field at that location, and σ is a material dependent parameter called the conductivity. This reformulation of Ohm's law is due to Gustav Kirchhoff.[4]

Contents

Full article ▸

related documents
Roche limit
Parallax
Angular momentum
Frame of reference
Main sequence
Bose–Einstein condensate
Casimir effect
Torque
Infrared
Lens (optics)
Permittivity
Fluid dynamics
Atomic orbital
Doppler effect
Warp drive
Standard Model
Bohm interpretation
Geodesy
Magnetohydrodynamics
Harmonic oscillator
Kinematics
Modified Newtonian dynamics
Sundial
Planets beyond Neptune
List of relativistic equations
Second law of thermodynamics
Phonon
Electromagnetic radiation
Lorentz force
Kilogram