Get it on Google Play
New! Download Unionpedia on your Android™ device!
Faster access than browser!
New! Don't lose this page! » Create account

Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. [1]

98 relations: Alternating current, American Journal of Physics, Ampere, Atom, Barlow's law, Classical and quantum conductivity, Classical mechanics, Complex number, Condensed matter physics, Constitutive equation, Coulomb, Coulomb's law, Crystallographic defect, Current density, Current–voltage characteristic, Derivative, Dictionary of Scientific Biography, Differential equation, Direct current, Drift velocity, Drude model, Electric current, Electric field, Electric potential, Electrical breakdown, Electrical conductor, Electrical impedance, Electrical network, Electrical resistance and conductance, Electrical resistivity and conductivity, Electromotive force, Electron, Electronic structure, Ensemble average, Euler's formula, Fick's laws of diffusion, Flux, Galvanometer, Georg Ohm, Green–Kubo relations, Gustav Kirchhoff, Hagen–Poiseuille equation, Heat, Henry Cavendish, Hydraulic analogy, International System of Units, Ion, Isotope, James Clerk Maxwell, Johnson–Nyquist noise, ..., Joseph Fourier, Joule heating, Laminar flow, Leyden jar, Litre, Lorentz force, Lorentz transformation, LTI system theory, Matter, Maximum power transfer theorem, Maxwell's equations, Momentum, Network analysis (electrical circuits), Norton's theorem, Number density, Ohm, Pascal (unit), Paul Drude, Plasma (physics), Popular Science, Pounds per square inch, Proportionality (mathematics), Quantum mechanics, Resistor, Rest frame, Robert Andrews Millikan, Samuel Morse, Scalar (mathematics), Scattering, Scientific law, Sheet resistance, Siemens (unit), Sigma, Silicon, Sine wave, Superposition theorem, Temperature, Thévenin's theorem, Thermal conductivity, Thermocouple, Time-invariant system, Turbulence, Vector (mathematics and physics), Volt, Voltage, Voltaic pile, Werner von Siemens, Winfield Hill. Expand index (48 more) »

Alternating current

Alternating current (AC), is an electric current in which the flow of electric charge periodically reverses direction, whereas in direct current (DC, also dc), the flow of electric charge is only in one direction.

New!!: Ohm's law and Alternating current · See more »

American Journal of Physics

The American Journal of Physics is a monthly, peer-reviewed scientific journal published by the American Association of Physics Teachers and the American Institute of Physics.

New!!: Ohm's law and American Journal of Physics · See more »


The ampere (SI unit symbol: A), often shortened to "amp",SI supports only the use of symbols and deprecates the use of abbreviations for units.

New!!: Ohm's law and Ampere · See more »


An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.

New!!: Ohm's law and Atom · See more »

Barlow's law

Barlow's law was an incorrect physical law proposed by Peter Barlow in 1825 to describe the ability of wires to conduct electricity.

New!!: Ohm's law and Barlow's law · See more »

Classical and quantum conductivity

Classical and quantum mechanical views of conductivity have both described the movements of electrons in a metallic solid.

New!!: Ohm's law and Classical and quantum conductivity · See more »

Classical mechanics

In physics, classical mechanics and quantum mechanics are the two major sub-fields of mechanics.

New!!: Ohm's law and Classical mechanics · See more »

Complex number

A complex number is a number that can be expressed in the form, where and are real numbers and is the imaginary unit, that satisfies the equation.

New!!: Ohm's law and Complex number · See more »

Condensed matter physics

Condensed matter physics is a branch of physics that deals with the physical properties of condensed phases of matter.

New!!: Ohm's law and Condensed matter physics · See more »

Constitutive equation

In physics and engineering, a constitutive equation or constitutive relation is a relation between two physical quantities (especially kinetic quantities as related to kinematic quantities) that is specific to a material or substance, and approximates the response of that material to external stimuli, usually as applied fields or forces.

New!!: Ohm's law and Constitutive equation · See more »


The coulomb (unit symbol: C) is the International System of Units (SI) unit of electric charge.

New!!: Ohm's law and Coulomb · See more »

Coulomb's law

Coulomb's law, or Coulomb's inverse-square law, is a law of physics describing the electrostatic interaction between electrically charged particles.

New!!: Ohm's law and Coulomb's law · See more »

Crystallographic defect

Crystalline solids exhibit a periodic crystal structure.

New!!: Ohm's law and Crystallographic defect · See more »

Current density

In electromagnetism, current density is the electric current per unit area of cross section.

New!!: Ohm's law and Current density · See more »

Current–voltage characteristic

A current–voltage characteristic or I–V curve (current–voltage curve) is a relationship, typically represented as a chart or graph, between the electric current through a circuit, device, or material, and the corresponding voltage, or potential difference across it.

New!!: Ohm's law and Current–voltage characteristic · See more »


The derivative of a function of a real variable measures the sensitivity to change of a quantity (a function value or dependent variable) which is determined by another quantity (the independent variable).

New!!: Ohm's law and Derivative · See more »

Dictionary of Scientific Biography

The Dictionary of Scientific Biography is a scholarly reference work that was published from 1970 through 1980.

New!!: Ohm's law and Dictionary of Scientific Biography · See more »

Differential equation

A differential equation is a mathematical equation that relates some function with its derivatives.

New!!: Ohm's law and Differential equation · See more »

Direct current

Direct current (DC) is the unidirectional flow of electric charge.

New!!: Ohm's law and Direct current · See more »

Drift velocity

The drift velocity is the flow velocity that a particle, such as an electron, attains due to an electric field.

New!!: Ohm's law and Drift velocity · See more »

Drude model

The Drude model of electrical conduction was proposed in 1900 by Paul Drude to explain the transport properties of electrons in materials (especially metals).

New!!: Ohm's law and Drude model · See more »

Electric current

An electric current is a flow of electric charge.

New!!: Ohm's law and Electric current · See more »

Electric field

The electric field is a component of the electromagnetic field.

New!!: Ohm's law and Electric field · See more »

Electric potential

An electric potential (also called the electric field potential or the electrostatic potential) is the amount of electric potential energy that a unitary point electric charge would have if located at any point in space, and is equal to the work done by an electric field in carrying a unit positive charge from infinity to that point.

New!!: Ohm's law and Electric potential · See more »

Electrical breakdown

Electrical breakdown or dielectric breakdown is a rapid reduction in the resistance of an electrical insulator when the voltage applied across it exceeds the breakdown voltage.

New!!: Ohm's law and Electrical breakdown · See more »

Electrical conductor

In physics and electrical engineering, a conductor is an object or type of material that allows the flow of electrical current in one or more directions.

New!!: Ohm's law and Electrical conductor · See more »

Electrical impedance

Electrical impedance is the measure of the opposition that a circuit presents to a current when a voltage is applied.

New!!: Ohm's law and Electrical impedance · See more »

Electrical network

An electrical network is an interconnection of electrical components (e.g. batteries, resistors, inductors, capacitors, switches) or a model of such an interconnection, consisting of electrical elements (e.g. voltage sources, current sources, resistances, inductances, capacitances).

New!!: Ohm's law and Electrical network · See more »

Electrical resistance and conductance

The electrical resistance of an electrical conductor is a measure of the difficulty to pass an electric current through that conductor.

New!!: Ohm's law and Electrical resistance and conductance · See more »

Electrical resistivity and conductivity

Electrical resistivity (also known as resistivity, specific electrical resistance, or volume resistivity) is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current.

New!!: Ohm's law and Electrical resistivity and conductivity · See more »

Electromotive force

Electromotive force, also called emf (denoted \mathcal and measured in volt), is the voltage developed by any source of electrical energy such as a battery or dynamo.

New!!: Ohm's law and Electromotive force · See more »


The electron is a subatomic particle, symbol or, with a negative elementary electric charge.

New!!: Ohm's law and Electron · See more »

Electronic structure

In quantum chemistry, electronic structure is the state of motion of electrons in an electrostatic field created by stationary nuclei.

New!!: Ohm's law and Electronic structure · See more »

Ensemble average

In statistical mechanics, the ensemble average is defined as the mean of a quantity that is a function of the microstate of a system (the ensemble of possible states), according to the distribution of the system on its micro-states in this ensemble.

New!!: Ohm's law and Ensemble average · See more »

Euler's formula

Euler's formula, named after Leonhard Euler, is a mathematical formula in complex analysis that establishes the fundamental relationship between the trigonometric functions and the complex exponential function.

New!!: Ohm's law and Euler's formula · See more »

Fick's laws of diffusion

Fick's laws of diffusion describe diffusion and were derived by Adolf Fick in 1855.

New!!: Ohm's law and Fick's laws of diffusion · See more »


In the various subfields of physics, there exist two common usages of the term flux, each with rigorous mathematical frameworks.

New!!: Ohm's law and Flux · See more »


A galvanometer is a type of sensitive ammeter: an instrument for detecting electric current.

New!!: Ohm's law and Galvanometer · See more »

Georg Ohm

Georg Simon Ohm (16 March 1789 – 6 July 1854) was a German physicist and mathematician.

New!!: Ohm's law and Georg Ohm · See more »

Green–Kubo relations

The Green–Kubo relations (Melville S. Green 1954, Ryogo Kubo 1957) give the exact mathematical expression for transport coefficients \gamma in terms of integrals of time correlation functions.

New!!: Ohm's law and Green–Kubo relations · See more »

Gustav Kirchhoff

Gustav Robert Kirchhoff (12 March 1824 – 17 October 1887) was a German physicist who contributed to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects.

New!!: Ohm's law and Gustav Kirchhoff · See more »

Hagen–Poiseuille equation

In nonideal fluid dynamics, the Hagen–Poiseuille equation, also known as the Hagen–Poiseuille law, Poiseuille law or Poiseuille equation, is a physical law that gives the pressure drop in an incompressible and Newtonian fluid in laminar flow flowing through a long cylindrical pipe of constant cross section.

New!!: Ohm's law and Hagen–Poiseuille equation · See more »


In physics, heat is energy in a process of transfer between a system and its surroundings, other than as work or with the transfer of matter.

New!!: Ohm's law and Heat · See more »

Henry Cavendish

Henry Cavendish FRS (10 October 1731 – 24 February 1810) was a British natural philosopher, scientist, and an important experimental and theoretical chemist and physicist.

New!!: Ohm's law and Henry Cavendish · See more »

Hydraulic analogy

The electronic–hydraulic analogy (derisively referred to as the drain-pipe theory by Oliver Lodge) is the most widely used analogy for "electron fluid" in a metal conductor.

New!!: Ohm's law and Hydraulic analogy · See more »

International System of Units

The International System of Units (Système International d'Unités, SI) is the modern form of the metric system, and is the most widely used system of measurement.

New!!: Ohm's law and International System of Units · See more »


An ion is an atom or a molecule in which the total number of electrons is not equal to the total number of protons, giving the atom or molecule a net positive or negative electrical charge.

New!!: Ohm's law and Ion · See more »


Isotopes are variants of a particular chemical element which differ in neutron number, although all isotopes of a given element have the same number of protons in each atom.

New!!: Ohm's law and Isotope · See more »

James Clerk Maxwell

James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish scientist in the field of mathematical physics.

New!!: Ohm's law and James Clerk Maxwell · See more »

Johnson–Nyquist noise

Johnson–Nyquist noise (thermal noise, Johnson noise, or Nyquist noise) is the electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical conductor at equilibrium, which happens regardless of any applied voltage.

New!!: Ohm's law and Johnson–Nyquist noise · See more »

Joseph Fourier

Jean-Baptiste Joseph Fourier (21 March 1768 – 16 May 1830) was a French mathematician and physicist born in Auxerre and best known for initiating the investigation of Fourier series and their applications to problems of heat transfer and vibrations.

New!!: Ohm's law and Joseph Fourier · See more »

Joule heating

Joule heating, also known as ohmic heating and resistive heating, is the process by which the passage of an electric current through a conductor releases heat.

New!!: Ohm's law and Joule heating · See more »

Laminar flow

In fluid dynamics, laminar flow (or streamline flow) occurs when a fluid flows in parallel layers, with no disruption between the layers.

New!!: Ohm's law and Laminar flow · See more »

Leyden jar

A Leyden jar, or Leiden jar, is a device that "stores" static electricity between two electrodes on the inside and outside of a glass jar.

New!!: Ohm's law and Leyden jar · See more »


The litre (International spelling) or liter (American spelling) (SI symbols L or l, commonly abbreviated as ltr) is an SI accepted metric system unit of volume equal to 1 cubic decimetre (dm3), 1,000 cubic centimetres (cm3) or 1/1,000 cubic metre.

New!!: Ohm's law and Litre · See more »

Lorentz force

In physics, particularly electromagnetism, the Lorentz force is the combination of electric and magnetic force on a point charge due to electromagnetic fields.

New!!: Ohm's law and Lorentz force · See more »

Lorentz transformation

In physics, the Lorentz transformation (or transformations) is named after the Dutch physicist Hendrik Lorentz.

New!!: Ohm's law and Lorentz transformation · See more »

LTI system theory

Linear time-invariant theory, commonly known as LTI system theory, comes from applied mathematics and has direct applications in NMR spectroscopy, seismology, circuits, signal processing, control theory, and other technical areas.

New!!: Ohm's law and LTI system theory · See more »


Before the 20th century, the term matter included ordinary matter composed of atoms and excluded other energy phenomena such as light or sound.

New!!: Ohm's law and Matter · See more »

Maximum power transfer theorem

In electrical engineering, the maximum power transfer theorem states that, to obtain maximum external power from a source with a finite internal resistance, the resistance of the load must equal the resistance of the source as viewed from its output terminals.

New!!: Ohm's law and Maximum power transfer theorem · See more »

Maxwell's equations

Maxwell's equations are a set of partial differential equations that, together with the Lorentz force law, form the foundation of classical electrodynamics, classical optics, and electric circuits.

New!!: Ohm's law and Maxwell's equations · See more »


In classical mechanics, linear momentum or translational momentum (pl. momenta; SI unit kg m/s, or equivalently, N s) is the product of the mass and velocity of an object.

New!!: Ohm's law and Momentum · See more »

Network analysis (electrical circuits)

A network, in the context of electronics, is a collection of interconnected components.

New!!: Ohm's law and Network analysis (electrical circuits) · See more »

Norton's theorem

Known in Europe as the Mayer–Norton theorem, Norton's theorem holds, to illustrate in DC circuit theory terms, that (see image): For AC systems the theorem can be applied to reactive impedances as well as resistances.

New!!: Ohm's law and Norton's theorem · See more »

Number density

In physics, astronomy, chemistry, biology and geography, number density (symbol: n or ρN) is an intensive quantity used to describe the degree of concentration of countable objects (particles, molecules, phonons, cells, galaxies, etc.) in physical space: three-dimensional volume number density, two-dimensional area number density, or one-dimensional line number density.

New!!: Ohm's law and Number density · See more »


The ohm (symbol: Ω) is the SI derived unit of electrical resistance, named after German physicist Georg Simon Ohm.

New!!: Ohm's law and Ohm · See more »

Pascal (unit)

The pascal (symbol: Pa) is the SI derived unit of pressure, internal pressure, stress, Young's modulus and ultimate tensile strength, defined as one newton per square metre.

New!!: Ohm's law and Pascal (unit) · See more »

Paul Drude

Paul Karl Ludwig Drude (July 12, 1863 – July 5, 1906) was a German physicist specializing in optics.

New!!: Ohm's law and Paul Drude · See more »

Plasma (physics)

Plasma (from Greek πλάσμα, "anything formed") is one of the four fundamental states of matter, the others being solid, liquid, and gas.

New!!: Ohm's law and Plasma (physics) · See more »

Popular Science

Popular Science (also known as PopSci) is an American monthly magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects.

New!!: Ohm's law and Popular Science · See more »

Pounds per square inch

The pound per square inch or, more accurately, pound-force per square inch (abbreviations: psi, lbf/in2, lbf/in2, lbf/sq in, lbf/sq in) is a unit of pressure or of stress based on avoirdupois units.

New!!: Ohm's law and Pounds per square inch · See more »

Proportionality (mathematics)

In mathematics, two variables are proportional if a change in one is always accompanied by a change in the other, and if the changes are always related by use of a constant multiplier.

New!!: Ohm's law and Proportionality (mathematics) · See more »

Quantum mechanics

Quantum mechanics (QM; also known as quantum physics, or quantum theory), including quantum field theory, is a fundamental branch of physics concerned with processes involving, for example, atoms and photons.

New!!: Ohm's law and Quantum mechanics · See more »


A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element.

New!!: Ohm's law and Resistor · See more »

Rest frame

In special relativity the rest frame of a particle is the coordinate system (frame of reference) in which the particle is at rest.

New!!: Ohm's law and Rest frame · See more »

Robert Andrews Millikan

Robert A. Millikan (March 22, 1868 – December 19, 1953) was an American experimental physicist honored with the Nobel Prize for Physics in 1923 for his measurement of the elementary electronic charge and for his work on the photoelectric effect.

New!!: Ohm's law and Robert Andrews Millikan · See more »

Samuel Morse

Samuel Finley Breese Morse (April 27, 1791 – April 2, 1872) was an American painter and inventor.

New!!: Ohm's law and Samuel Morse · See more »

Scalar (mathematics)

In linear algebra, real numbers are called scalars and relate to vectors in a vector space through the operation of scalar multiplication, in which a vector can be multiplied by a number to produce another vector.

New!!: Ohm's law and Scalar (mathematics) · See more »


Scattering is a general physical process where some forms of radiation, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by one or more paths due to localized non-uniformities in the medium through which they pass.

New!!: Ohm's law and Scattering · See more »

Scientific law

A scientific law is a statement based on repeated experimental observations that describes some aspects of the universe.

New!!: Ohm's law and Scientific law · See more »

Sheet resistance

Sheet resistance is a measure of resistance of thin films that are nominally uniform in thickness.

New!!: Ohm's law and Sheet resistance · See more »

Siemens (unit)

The siemens (SI unit symbol: S) is the unit of electric conductance, electric susceptance and electric admittance in the International System of Units (SI).

New!!: Ohm's law and Siemens (unit) · See more »


Sigma (upper-case Σ, lower-case σ, lower-case in word-final position ς; Greek σίγμα) is the eighteenth letter of the Greek alphabet.

New!!: Ohm's law and Sigma · See more »


Silicon is a chemical element with symbol Si and atomic number 14.

New!!: Ohm's law and Silicon · See more »

Sine wave

The sine wave or sinusoid is a mathematical curve that describes a smooth repetitive oscillation.

New!!: Ohm's law and Sine wave · See more »

Superposition theorem

The superposition theorem for electrical circuits states that for a linear system the response (voltage or current) in any branch of a bilateral linear circuit having more than one independent source equals the algebraic sum of the responses caused by each independent source acting alone, where all the other independent sources are replaced by their internal impedances.

New!!: Ohm's law and Superposition theorem · See more »


A temperature is an objective comparative measure of hot or cold.

New!!: Ohm's law and Temperature · See more »

Thévenin's theorem

As originally stated in terms of DC resistive circuits only, Thévenin's theorem holds that: In circuit theory terms, the theorem allows any one-port network to be reduced to a single voltage source and a single impedance.

New!!: Ohm's law and Thévenin's theorem · See more »

Thermal conductivity

In physics, thermal conductivity (often denoted k, λ, or κ) is the property of a material to conduct heat.

New!!: Ohm's law and Thermal conductivity · See more »


A thermocouple is a device consisting of two dissimilar conductors or semiconductors that contact each other at one or more points.

New!!: Ohm's law and Thermocouple · See more »

Time-invariant system

A time-invariant (TIV) system is a system whose output does not depend explicitly on time.

New!!: Ohm's law and Time-invariant system · See more »


In fluid dynamics, turbulence or turbulent flow is a flow regime characterized by chaotic property changes.

New!!: Ohm's law and Turbulence · See more »

Vector (mathematics and physics)

When used without any further description, vector refers either to.

New!!: Ohm's law and Vector (mathematics and physics) · See more »


The volt (symbol) is the derived unit for electric potential, electric potential difference (voltage), and electromotive force.

New!!: Ohm's law and Volt · See more »


Voltage, electric potential difference, electric pressure or electric tension (denoted or) is the difference in electric potential energy between two points per unit electric charge.

New!!: Ohm's law and Voltage · See more »

Voltaic pile

The voltaic pile was the first electrical battery that could continuously provide an electrical current to a circuit.

New!!: Ohm's law and Voltaic pile · See more »

Werner von Siemens

Ernst Werner Siemens (von Siemens since 1888;; 13 December 1816 – 6 December 1892) was a German inventor and industrialist.

New!!: Ohm's law and Werner von Siemens · See more »

Winfield Hill

Winfield Hill is the Director of the Electronics Engineering Laboratory at the Rowland Institute at Harvard University.

New!!: Ohm's law and Winfield Hill · See more »

Redirects here:

I=U/R, Ohm Law, Ohm law, Ohm's Law, Ohm's Laws, Ohm's law of electricity, Ohms Law, Ohms law, Ohms' Law, Ohm’s law, R=U/I, U=R*I, U=ri, V = IR, V=IR.


[1] https://en.wikipedia.org/wiki/Ohm's_law

Hey! We are on Facebook now! »