Electromagnetism

Electricity · Magnetism Electrostatics Electric charge · Coulomb's law Electric field · Gauss' law Electric potential · Electrostatic induction Electric dipole moment Magnetostatics Ampère's law · Electric current Magnetic field · Magnetic flux Biot-Savart law Magnetic dipole moment Gauss's law for magnetism Electrodynamics Free space Lorentz force law EMF · Electromagnetic induction Faraday's law · Displacement current Maxwell's equations · EM field Electromagnetic radiation Liénard-Wiechert Potentials Maxwell tensor · Eddy current Electrical Network Electrical conduction · Electrical resistance · Capacitance · Inductance · Impedance · Resonant cavities · Waveguides Covariant formulation Electromagnetic tensor EM Stress-energy tensor Four-current · Four-potential Scientists · Ampere · Coulomb · Faraday · Heaviside · Henry · Hertz · Lorentz · Maxwell · Weber

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Electromagnetism is the physics of the electromagnetic field: a field which exerts a force on particles that possess the property of electric charge, and is in turn affected by the presence and motion of those particles. Image File history File links Solenoid. ... Electricity (from New Latin Ä“lectricus, amberlike) is a general term for a variety of phenomena resulting from the presence and flow of electric charge. ... For other senses of this word, see magnetism (disambiguation). ... Electrostatics (also known as static electricity) is the branch of physics that deals with the phenomena arising from what seem to be stationary electric charges. ... This box:      Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. ... This box:      Coulombs torsion balance Coulombs law, developed in the 1780s by French physicist Charles Augustin de Coulomb, may be stated in scalar form as follows: The magnitude of the electrostatic force between two point electric charges is directly proportional to the product of the magnitudes of each... In physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field. ... In physics, Gausss law gives the relation between the electric flux flowing out a closed surface and the charge enclosed in the surface. ... This box:      At a point in space, the electric potential is the potential energy per unit of charge that is associated with a static (time-invariant) electric field. ... Electrostatic induction is a method by which an electrically charged object can be used to create an electrical charge in a second object, without contact between the two objects. ... This article is about the electromagnetic phenomenon. ... Magnetostatics is the study of static magnetic fields. ... In physics, Ampères Circuital law, discovered by André-Marie Ampère, relates the circulating magnetic field in a closed loop to the electric current passing through the loop. ... This box:      Electric current is the flow (movement) of electric charge. ... For the indie-pop band, see The Magnetic Fields. ... Magnetic flux, represented by the Greek letter Φ (phi), is a measure of quantity of magnetism, taking account of the strength and the extent of a magnetic field. ... The Biot-Savart law is a physical law with applications in both electromagnetics and fluid dynamics. ... A bar magnet. ... Classical electrodynamics (or classical electromagnetism) is a theory of electromagnetism that was developed over the course of the 19th century, most prominently by James Clerk Maxwell. ... In physics, free space is a concept of electromagnetic theory, corresponding roughly to the vacuum, the baseline state of the electromagnetic field, or the replacement for the electromagnetic aether. ... Lorentz force. ... Electromotive force (emf) is the amount of energy gained per unit charge that passes through a device in the opposite direction to the electric field existing across that device. ... For magnetic induction, see Magnetic field. ... Faradays law of induction (more generally, the law of electromagnetic induction) states that the induced emf (electromotive force) in a closed loop equals the negative of the time rate of change of magnetic flux through the loop. ... Displacement current is a quantity related to changing electric field. ... For thermodynamic relations, see Maxwell relations. ... The electromagnetic field is a physical field that is produced by electrically charged objects and which affects the behaviour of charged objects in the vicinity of the field. ... This box:      Electromagnetic (EM) radiation is a self-propagating wave in space with electric and magnetic components. ... The Liénard-Wiechert potential describes the electromagnetic effect of a moving charge. ... In physics, the Maxwell stress tensor is the stress tensor of an electromagnetic field. ... As the circular plate moves down through a small region of constant magnetic field directed into the page, eddy currents are induced in the plate. ... A simple electric circuit made up of a voltage source and a resistor. ... Conduction is the movement of electrically charged particles through a transmission medium (electrical conductor). ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... Capacitance is a measure of the amount of electric charge stored (or separated) for a given electric potential. ... An electric current i flowing around a circuit produces a magnetic field and hence a magnetic flux Φ through the circuit. ... Electrical impedance, or simply impedance, is a measure of opposition to a sinusoidal alternating electric current. ... A resonator is a device or part that vibrates (or oscillates) with waves. ... This box:      This page is about waveguides for electromagnetic wave propagation at microwave and radio wave frequencies. ... In special relativity, in order to more clearly express the fact that Maxwells equations (in vacuum) take the same form in any inertial coordinate system, the vacuum Maxwells equations are written in terms of four-vectors and tensors in the manifestly covariant form (cgs units): , and where is... This box:      The electromagnetic tensor or electromagnetic field tensor (sometimes called the field strength tensor, Faraday tensor or Maxwell bivector) is a mathematical object that describes the electromagnetic field of a physical system in Maxwells theory of electromagnetism. ... In physics, the electromagnetic stress-energy tensor is the portion of the stress-energy tensor due to the electromagnetic field. ... In special and general relativity, the four-current is the Lorentz covariant four-vector that replaces the electromagnetic current density where c is the speed of light, ρ the charge density, and j the conventional current density. ... The electromagnetic four-potential is a four-vector defined in SI units (and gaussian units in parentheses) as in which φ is the electrical potential, and is the magnetic potential, a vector potential. ... André-Marie Ampère (January 20, 1775 – June 10, 1836), was a French physicist who is generally credited as one of the main discoverers of electromagnetism. ... Charles Augustin de Coulomb (born June 14, 1736, Angoulême, France - died August 23, 1806, Paris, France) was a French physicist. ... Michael Faraday, FRS (September 22, 1791 – August 25, 1867) was an English chemist and physicist (or natural philosopher, in the terminology of that time) who contributed to the fields of electromagnetism and electrochemistry. ... Oliver Heaviside (May 18, 1850 – February 3, 1925) was a self-taught English electrical engineer, mathematician, and physicist who adapted complex numbers to the study of electrical circuits, developed techniques for applying Laplace transforms to the solution of differential equations, reformulated Maxwells field equations in terms of electric and... Joseph Henry Joseph Henry (December 17, 1797 – May 13, 1878) was a Scottish-American scientist who served as the first Secretary of the Smithsonian Institution. ... Heinrich Rudolf Hertz (February 22, 1857 - January 1, 1894) was the German physicist and mechanician for whom the hertz, an SI unit, is named. ... Hendrik Lorentz by Jan Veth Hendrik Antoon Lorentz (born July 18, 1853 in Arnhem, Netherlands; died February 4, 1928 in Haarlem, Netherlands) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. ... James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and theoretical physicist. ... Wilhelm Eduard Weber (October 24, 1804 - June 23, 1891) was a noted physicist. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... The electromagnetic field is a physical field that is produced by electrically charged objects and which affects the behaviour of charged objects in the vicinity of the field. ... The magnitude of an electric field surrounding two equally charged (repelling) particles. ... For other uses, see Force (disambiguation). ... For the novel, see The Elementary Particles. ... This box:      Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. ...

A changing magnetic field produces an electric field (this is the phenomenon of electromagnetic induction, the basis of operation for electrical generators, induction motors, and transformers). Similarly, a changing electric field generates a magnetic field. Because of this interdependence of the electric and magnetic fields, it makes sense to consider them as a single coherent entity - the electromagnetic field. For the indie-pop band, see The Magnetic Fields. ... In physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field. ... For magnetic induction, see Magnetic field. ... This article is about machines that produce electricity. ... Induction Motor (IM) is one kind of AC motor where power is supplied to the rotating device by induction. ... For other uses, see Transformer (disambiguation). ...

The magnetic field is produced by the motion of electric charges, i.e. electric current. The magnetic field causes the magnetic force associated with magnets. Electric charge is a fundamental property of some subatomic particles, which determines their electromagnetic interactions. ... This box:      Electric current is the flow (movement) of electric charge. ... For other uses, see Magnet (disambiguation). ...

The theoretical implications of electromagnetism led to the development of special relativity by Albert Einstein in 1905. For a less technical and generally accessible introduction to the topic, see Introduction to special relativity. ... “Einstein” redirects here. ...

History

While preparing for an evening lecture on 21 April 1820, Hans Christian Ørsted developed an experiment which provided evidence that surprised him. As he was setting up his materials, he noticed a compass needle deflected from magnetic north when the electric current from the battery he was using was switched on and off. This deflection convinced him that magnetic fields radiate from all sides of a wire carrying an electric current, just as light and heat do, and that it confirmed a direct relationship between electricity and magnetism. Ørsted redirects here. ...

At the time of discovery, Ørsted did not suggest any satisfactory explanation of the phenomenon, nor did he try to represent the phenomenon in a mathematical framework. However, three months later he began more intensive investigations. Soon thereafter he published his findings, proving that an electric current produces a magnetic field as it flows through a wire. The CGS unit of magnetic induction (oersted) is named in honor of his contributions to the field of electromagnetism.

His findings resulted in intensive research throughout the scientific community in electrodynamics. They influenced French physicist André-Marie Ampère's developments of a single mathematical form to represent the magnetic forces between current-carrying conductors. Ørsted's discovery also represented a major step toward a unified concept of energy. Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ... André-Marie Ampère (January 20, 1775 – June 10, 1836), was a French physicist who is generally credited as one of the main discoverers of electromagnetism. ...

Ørsted was not the first person to examine the relation between electricity and magnetism. In 1802 Gian Domenico Romagnosi, an Italian legal scholar, deflected a magnetic needle by electrostatic charges. He interpreted his observations as The Relation between electricity and magnetism. Actually, no galvanic current existed in the setup and hence no electromagnetism was present. An account of the discovery was published in 1802 in an Italian newspaper, but it was largely overlooked by the contemporary scientific community. Gian Domenico Romagnosi Gian Domenico Romagnosi (December 11, 1761 – June 8, 1835) was an Italian philosopher, economist and jurist. ...

This unification, which was observed by Michael Faraday, extended by James Clerk Maxwell, and partially reformulated by Oliver Heaviside and Heinrich Hertz, is one of the triumphs of 19th century physics. It had far-reaching consequences, one of which was the understanding of the nature of light. As it turns out, what is thought of as "light" is actually a propagating oscillatory disturbance in the electromagnetic field, i.e., an electromagnetic wave. Different frequencies of oscillation give rise to the different forms of electromagnetic radiation, from radio waves at the lowest frequencies, to visible light at intermediate frequencies, to gamma rays at the highest frequencies. Michael Faraday, FRS (September 22, 1791 – August 25, 1867) was an English chemist and physicist (or natural philosopher, in the terminology of that time) who contributed to the fields of electromagnetism and electrochemistry. ... James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and theoretical physicist. ... Oliver Heaviside (May 18, 1850 – February 3, 1925) was a self-taught English electrical engineer, mathematician, and physicist who adapted complex numbers to the study of electrical circuits, developed techniques for applying Laplace transforms to the solution of differential equations, reformulated Maxwells field equations in terms of electric and... Heinrich Rudolf Hertz (February 22, 1857 - January 1, 1894) was the German physicist and mechanician for whom the hertz, an SI unit, is named. ... For other uses, see Light (disambiguation). ... Oscillation is the variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. ... Surface waves in water This article is about waves in the most general scientific sense. ... For other uses, see Frequency (disambiguation). ... This box:      Electromagnetic (EM) radiation is a self-propagating wave in space with electric and magnetic components. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ... This article is about electromagnetic radiation. ...

The electromagnetic force

Main article: Electromagnetic force

The force that the electromagnetic field exerts on electrically charged particles, called the electromagnetic force, is one of the four fundamental forces. The other fundamental forces are the strong nuclear force (which holds atomic nuclei together), the weak nuclear force (which causes certain forms of radioactive decay), and the gravitational force. All other forces are ultimately derived from these fundamental forces. In physics, the electromagnetic force is the force that the electromagnetic field exerts on electrically charged particles. ... A fundamental interaction is a mechanism by which particles interact with each other, and which cannot be explained by another more fundamental interaction. ... The strong interaction or strong force is today understood to represent the interactions between quarks and gluons as detailed by the theory of quantum chromodynamics (QCD). ... The nucleus of an atom is the very small dense region, of positive charge, in its centre consisting of nucleons (protons and neutrons). ... The weak interaction (often called the weak force or sometimes the weak nuclear force) is one of the four fundamental interactions of nature. ... Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves. ... Gravity is a force of attraction that acts between bodies that have mass. ...

The electromagnetic force is the one responsible for practically all the phenomena encountered in daily life, with the exception of gravity. All the forces involved in interactions between atoms can be traced to the electromagnetic force acting on the electrically charged protons and electrons inside the atoms. This includes the forces we experience in "pushing" or "pulling" ordinary material objects, which come from the intermolecular forces between the individual molecules in our bodies and those in the objects. It also includes all forms of chemical phenomena, which arise from interactions between electron orbitals. For other uses, see Atom (disambiguation). ... For other uses, see Proton (disambiguation). ... For other uses, see Electron (disambiguation). ... In physics, chemistry, and biology, intermolecular forces are forces that act between stable molecules or between functional groups of macromolecules. ... 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ... For other uses, see Chemistry (disambiguation). ... In chemistry, a molecular orbital is a region in which an electron may be found in a molecule. ...

Classical electrodynamics

Main article: Classical electrodynamics

The scientist William Gilbert proposed, in his De Magnete (1600), that electricity and magnetism, while both capable of causing attraction and repulsion of objects, were distinct effects. Mariners had noticed that lightning strikes had the ability to disturb a compass needle, but the link between lightning and electricity was not confirmed until Benjamin Franklin's proposed experiments in 1752. One of the first to discover and publish a link between man-made electric current and magnetism was Romagnosi, who in 1802 noticed that connecting a wire across a Voltaic pile deflected a nearby compass needle. However, the effect did not become widely known until 1820, when Ørsted performed a similar experiment. Ørsted's work influenced Ampère to produce a theory of electromagnetism that set the subject on a mathematical foundation. Classical electromagnetism is a theory of electromagnetism that was developed over the course of the 19th century, most prominently by James Clerk Maxwell. ... For other persons named William Gilbert, see William Gilbert (disambiguation). ... De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure (On the Magnet and Magnetic Bodies, and on That Great Magnet the Earth) is a scientific work published in 1600 by the English physician and scientist William Gilbert. ... Benjamin Franklin (January 17 [O.S. January 6] 1706 – April 17, 1790) was one of the most well known Founding Fathers of the United States. ... Gian Domenico Romagnosi Gian Domenico Romagnosi (December 11, 1761 – June 8, 1835) was an Italian philosopher, economist and jurist. ... A copper-zinc Voltaic pile A Voltaic pile on display in the Tempio Voltiano The Voltaic pile is the first modern electric battery, invented by Alessandro Volta in 1800. ... This article is about the navigational instrument. ... Ørsted redirects here. ... André-Marie Ampère (January 20, 1775 – June 10, 1836), was a French physicist who is generally credited as one of the main discoverers of electromagnetism. ...

An accurate theory of electromagnetism, known as classical electromagnetism, was developed by various physicists over the course of the 19th century, culminating in the work of James Clerk Maxwell, who unified the preceding developments into a single theory and discovered the electromagnetic nature of light. In classical electromagnetism, the electromagnetic field obeys a set of equations known as Maxwell's equations, and the electromagnetic force is given by the Lorentz force law. Classical electrodynamics (or classical electromagnetism) is a theory of electromagnetism that was developed over the course of the 19th century, most prominently by James Clerk Maxwell. ... Not to be confused with physician, a person who practices medicine. ... James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and theoretical physicist. ... For thermodynamic relations, see Maxwell relations. ... Lorentz force. ...

One of the peculiarities of classical electromagnetism is that it is difficult to reconcile with classical mechanics, but it is compatible with special relativity. According to Maxwell's equations, the speed of light is a universal constant, dependent only on the electrical permittivity and magnetic permeability of the vacuum. This violates Galilean invariance, a long-standing cornerstone of classical mechanics. One way to reconcile the two theories is to assume the existence of a luminiferous aether through which the light propagates. However, subsequent experimental efforts failed to detect the presence of the aether. After important contributions of Hendrik Lorentz and Henri Poincaré, in 1905, Albert Einstein solved the problem with the introduction of special relativity, which replaces classical kinematics with a new theory of kinematics that is compatible with classical electromagnetism. (For more information, see History of special relativity.) Classical mechanics (commonly confused with Newtonian mechanics, which is a subfield thereof) is used for describing the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies. ... For a less technical and generally accessible introduction to the topic, see Introduction to special relativity. ... A line showing the speed of light on a scale model of Earth and the Moon, taking about 1â…“ seconds to traverse that distance. ... Permittivity is a physical quantity that describes how an electric field affects and is affected by a dielectric medium and is determined by the ability of a material to polarize in response to an applied electric field, and thereby to cancel, partially, the field inside the material. ... This article is in need of attention. ... Look up Vacuum in Wiktionary, the free dictionary. ... Galilean invariance is a principle which states that the fundamental laws of physics are the same in all inertial (uniform-velocity) frames of reference. ... The luminiferous aether: it was hypothesised that the Earth moves through a medium of aether that carries light In the late 19th century luminiferous aether (light-bearing aether) was the term used to describe a medium for the propagation of light. ... Hendrik Lorentz by Jan Veth Hendrik Antoon Lorentz (born July 18, 1853 in Arnhem, Netherlands; died February 4, 1928 in Haarlem, Netherlands) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. ... Jules Henri Poincaré (April 29, 1854 – July 17, 1912) (IPA: [1]) was one of Frances greatest mathematicians and theoretical physicists, and a philosopher of science. ... “Einstein” redirects here. ... For a less technical and generally accessible introduction to the topic, see Introduction to special relativity. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

In addition, relativity theory shows that in moving frames of reference a magnetic field transforms to a field with a nonzero electric component and vice versa; thus firmly showing that they are two sides of the same coin, and thus the term "electromagnetism". (For more information, see Classical electromagnetism and special relativity.)

The photoelectric effect

Main article: Photoelectric effect

In another paper published in that same year, Albert Einstein undermined the very foundations of classical electromagnetism. His theory of the photoelectric effect (for which he won the Nobel prize for physics) posited that light could exist in discrete particle-like quantities, which later came to be known as photons. Einstein's theory of the photoelectric effect extended the insights that appeared in the solution of the ultraviolet catastrophe presented by Max Planck in 1900. In his work, Planck showed that hot objects emit electromagnetic radiation in discrete packets, which leads to a finite total energy emitted as black body radiation. Both of these results were in direct contradiction with the classical view of light as a continuous wave. Planck's and Einstein's theories were progenitors of quantum mechanics, which, when formulated in 1925, necessitated the invention of a quantum theory of electromagnetism. This theory, completed in the 1940s, is known as quantum electrodynamics (or "QED"), and is one of the most accurate theories known to physics. A diagram illustrating the emission of electrons from a metal plate, requiring energy gained from an incoming photon to be more than the work function of the material. ... A diagram illustrating the emission of electrons from a metal plate, requiring energy gained from an incoming photon to be more than the work function of the material. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... The ultraviolet catastrophe, also called the Rayleigh-Jeans catastrophe, was a prediction of early 20th century classical physics that an ideal black body at thermal equilibrium will emit radiation with infinite power. ... Planck redirects here. ... This box:      Electromagnetic (EM) radiation is a self-propagating wave in space with electric and magnetic components. ... As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ... For a generally accessible and less technical introduction to the topic, see Introduction to quantum mechanics. ... Quantum electrodynamics (QED) is a relativistic quantum field theory of electrodynamics. ...

Definition

The term electrodynamics is sometimes used to refer to the combination of electromagnetism with mechanics, and deals with the effects of the electromagnetic field on the dynamic behavior of electrically charged particles. Electromagnetism is the physics of the electromagnetic field: a field, encompassing all of space, composed of the electric field and the magnetic field. ... For other uses, see Mechanic (disambiguation). ...

Units

Electromagnetic units are part of a system of electrical units based primarily upon the magnetic properties of electric currents, the fundamental cgs unit being the ampere. The units are:

In the electromagnetic cgs system, electrical current is a fundamental quantity defined via Ampère's law and takes the permeability as a dimensionless quantity (relative permeability) whose value in a vacuum is unity. As a consequence, the square of the speed of light appears explicitly in some of the equations interrelating quantities in this system. For other uses, see Ampere (disambiguation). ... The coulomb (symbol: C) is the SI unit of electric charge. ... Examples of various types of capacitors. ... The henry (symbol H) is the SI unit of inductance. ... A multimeter can be used to measure resistance in ohms. ... Josephson junction array chip developed by NIST as a standard volt. ... For other uses, see Watt (disambiguation). ... An electric current produces a magnetic field. ... In electromagnetism, permeability is the degree of magnetization of a material that responds linearly to an applied magnetic field. ...

Look up si, Si, SI in Wiktionary, the free dictionary. ... This box:      Electric current is the flow (movement) of electric charge. ... For other uses, see Ampere (disambiguation). ... Look up si, Si, SI in Wiktionary, the free dictionary. ... This box:      Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. ... In physics the term quantity of electricity refers to the quantity of electric charge. ... The coulomb (symbol: C) is the SI unit of electric charge. ... Potential difference is a quantity in physics related to the amount of energy that would be required to move an object from one place to another against various types of force. ... Electromotive force (emf) is the amount of energy gained per unit charge that passes through a device in the opposite direction to the electric field existing across that device. ... Josephson junction array chip developed by NIST as a standard volt. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... Electrical impedance, or simply impedance, is a measure of opposition to a sinusoidal alternating electric current. ... It has been suggested that Electric reactance be merged into this article or section. ... The ohm (symbol: Ω) is the SI unit of electric resistance. ... // Headline text POOP!! Danny Hornsby (also known as Gnome) is a measure indicating how strongly a Gnome can opposes the flow of electric current. ... The ohm (symbol: Ω) is the SI unit of electric resistance. ... This article is about the unit of length. ... Transmission lines in Lund, Sweden Electric power, often known as power or electricity, involves the production and delivery of electrical energy in sufficient quantities to operate domestic appliances, office equipment, industrial machinery and provide sufficient energy for both domestic and commercial lighting, heating, cooking and industrial processes. ... For other uses, see Watt (disambiguation). ... Capacitance is a measure of the amount of electric charge stored (or separated) for a given electric potential. ... Examples of various types of capacitors. ... Electrical elastance is the inverse of capacitance. ... Examples of various types of capacitors. ... In physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field. ... Josephson junction array chip developed by NIST as a standard volt. ... This article is about the unit of length. ... In physics, the electric displacement field or electric flux density or electric induction is a vector field that appears in Maxwells equations. ... The coulomb (symbol: C) is the SI unit of electric charge. ... A square metre (US spelling: square meter) is by definition the area enclosed by a square with sides each 1 metre long. ... Permittivity is a physical quantity that describes how an electric field affects and is affected by a dielectric medium and is determined by the ability of a material to polarize in response to an applied electric field, and thereby to cancel, partially, the field inside the material. ... Examples of various types of capacitors. ... This article is about the unit of length. ... The electric susceptibility χe of a dielectric material is a measure of how easily it polarizes in response to an electric field. ... Electrical conductance is the reciprocal of electrical resistance. ... In electrical engineering, the admittance (Y) is the inverse of the impedance (Z). ... In electrical engineering, the susceptance (B) is the imaginary part of the admittance. ... The siemens (symbol: S) is the SI derived unit of electric conductance. ... Not to be confused with electrical conductance, a measure of an objects or circuits ability to conduct an electric current between two points, which is dependent on the electrical conductivity and the geometric dimensions of the conducting object. ... The siemens (symbol: S) is the SI derived unit of electric conductance. ... This article is about the unit of length. ... For the indie-pop band, see The Magnetic Fields. ... SI unit. ... Magnetic flux, represented by the Greek letter Φ (phi), is a measure of quantity of magnetism, taking account of the strength and the extent of a magnetic field. ... In physics, the weber (symbol: Wb) is the SI unit of magnetic flux. ... For the indie-pop band, see The Magnetic Fields. ... For other uses, see Ampere (disambiguation). ... This article is about the unit of length. ... Magnetic reluctance is the resistance of a material to a magnetic field. ... The ampere-turn (AT) is a unit of magnetomotive force or magnetic potential, represented by a direct current of one ampere flowing in a single-turn loop in a vacuum. ... In physics, the weber (symbol: Wb) is the SI unit of magnetic flux. ... An electric current i flowing around a circuit produces a magnetic field and hence a magnetic flux Φ through the circuit. ... The henry (symbol H) is the SI unit of inductance. ... In electromagnetism, permeability is the degree of magnetization of a material that responds linearly to an applied magnetic field. ... The henry (symbol H) is the SI unit of inductance. ... This article is about the unit of length. ... In physics and electrical engineering, the magnetic susceptibility is the degree of magnetization of a material in response to an applied magnetic field. ...

See also

Electromagnetism Portal

Image File history File links Portal. ... The Abraham-Lorentz force is the average force on an accelerating charged particle caused by the particle emitting electromagnetic radiation. ... Classical electrodynamics (or classical electromagnetism) is a theory of electromagnetism that was developed over the course of the 19th century, most prominently by James Clerk Maxwell. ... Slit experiment redirects here. ... Electricity (from New Latin Ä“lectricus, amberlike) is a general term for a variety of phenomena resulting from the presence and flow of electric charge. ... An electromagnet is a type of magnet in which the magnetic field is produced by the flow of an electric current. ... Computational electromagnetics, computational electrodynamics or electromagnetic modeling refers to the process of modeling the interaction of electromagnetic fields with physical objects and the environment. ... Lasers used for visual effects during a musical performance. ... In engineering, electromechanics combines the sciences of electromagnetism of electrical engineering and mechanics. ... Electrostatics (also known as static electricity) is the branch of physics that deals with the phenomena arising from what seem to be stationary electric charges. ... This article or section does not cite its references or sources. ... Formulation ... Look up waveguide in Wiktionary, the free dictionary. ... Relativistic electromagnetism is the idea of explaining electromagnetism based on relativistic (Albert Einstein 1905) arguments. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...

References

This article or section includes a list of references or external links, but its sources remain unclear because it lacks in-text citations. You can improve this article by introducing more precise citations.

Web Image File history File links This is a lossless scalable vector image. ...

• Nave, R., Magnetic Field Strength H, <http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magfield.html>. Retrieved on 4 June 2007 
• Keitch, Paul, Magnetic Field Strength and Magnetic Flux Density, <http://www.electric-fields.bris.ac.uk/MagneticFieldStrength.htm>. Retrieved on 4 June 2007 
• Oppelt, Arnulf (2006-11-02), magnetic field strength, <http://searchsmb.techtarget.com/sDefinition/0,290660,sid44_gci763586,00.html>. Retrieved on 4 June 2007 
• magnetic field strength converter, <http://www.unitconversion.org/unit_converter/magnetic-field-strength.html>. Retrieved on 4 June 2007 
• Errante, Francesco, The hertzian radiation, better known as radio waves. What it is and how it happens, <http://www.esmartstart.com/_framed/250x/radiondistics/hertzian_radiation.htm>. Retrieved on 6 March 2008 

Books Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 306th day of the year (307th in leap years) in the Gregorian calendar. ...

• Durney, Carl H. and Johnson, Curtis C. (1969). Introduction to modern electromagnetics. McGraw-Hill. ISBN 0-07-018388-0. 
• Rao, Nannapaneni N. (1994). Elements of engineering electromagnetics (4th ed.). Prentice Hall. ISBN 0-13-948746-8. 
• Tipler, Paul (1998). Physics for Scientists and Engineers: Vol. 2: Light, Electricity and Magnetism, 4th ed., W. H. Freeman. ISBN 1-57259-492-6. 
• Griffiths, David J. (1998). Introduction to Electrodynamics, 3rd ed., Prentice Hall. ISBN 0-13-805326-X. 
• Jackson, John D. (1998). Classical Electrodynamics, 3rd ed., Wiley. ISBN 0-471-30932-X. 
• Rothwell, Edward J.; Cloud, Michael J. (2001). Electromagnetics. CRC Press. ISBN 0-8493-1397-X. 
• Wangsness, Roald K.; Cloud, Michael J. (1986). Electromagnetic Fields (2nd Edition). Wiley. ISBN 0-471-81186-6. 
• Dibner, Bern (1961). Oersted and the discovery of electromagnetism. Blaisdell Publishing Company. ISSN 99-0317066-1 ; 18. 

The McGraw-Hill Companies, Inc. ... Pearson can mean Pearson PLC the media conglomerate. ... David J. Griffiths is a U.S. physicist and educator. ...

External links

• The hertzian radiation, better known as radio waves. What it is and how it happens by Francesco Errante
• Circuit Construction Kit PhET at University of Colorado, Boulder
• Electromagnetic Tutorials and Forums EM Talk
• MIT Video Lectures - Electricity and Magnetism from Spring 2002. Taught by Professor Walter Lewin.
• Electricity and Magnetism - an online textbook (uses algebra, with optional calculus-based sections)
• Electromagnetic Field Theory - an online textbook (uses calculus)
• Classical Electromagnetism: An intermediate level course - an online intermediate level texbook downloadable as PDF file
• Science Aid: electromagnetism Electromagnetism, aimed at teens.
• Motion Mountain A modern introduction to electromagnetism and its effects in everyday life.
• Books on Electromagnetism and RF field
• Dr. David C. Jenn's site - specializing in radar systems and electromagnetic scattering and radiation
• Gallery of Electromagnetic Personalities
• MSci Electromagnetic Theory Lecture Notes
• PHY2206 Electromagnetic Fields Course Handouts
• Dr. David Kagan Physics 204B Lecture Notes
• Sophocles J. Orfanidis' Electromagnetic Waves and Antennas
• MAS207 Electromagnetism Lecture Notes
• PHYS1002 - Electromagnetism, Optics, Relativity and Quantum Physics I
• Dr. Zbigniew Ficek's PHYS3050 Electromagnetic theory lecture notes
• University of Cambridge's Advanced Physics Electromagnetism
• ECEN4364 Principles of RF and Microwave Measurements lecture notes
• B7 Relativity and Electromagnetism
• NMJ Woodhouse's Special Relativity and Electromagnetism
• NMJ Woodhouse's General Relativity
• Maxwell, Mechanism and the Nature of Electricity
• Electromagnetism Mathematica notes
• "National Grid", electromagnetic sound art
• "Disinformation", electromagnetic sound art
• Differential Forms in Electromagnetic Theory
• The Life of James Clerk Maxwell - prepared by James C. Rautio of Sonnet Software, Inc.
• Classical Electrodynamics and Theory of Relativity - by Ruslan Sharipov
• Axial Vectors - by Alain Bossavit

A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... Classical mechanics (commonly confused with Newtonian mechanics, which is a subfield thereof) is used for describing the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies. ... Thermodynamics (from the Greek θερμη, therme, meaning heat and δυναμις, dynamis, meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ... Statistical mechanics is the application of probability theory, which includes mathematical tools for dealing with large populations, to the field of mechanics, which is concerned with the motion of particles or objects when subjected to a force. ... For a generally accessible and less technical introduction to the topic, see Introduction to quantum mechanics. ... Two-dimensional analogy of space-time curvature described in General Relativity. ... Thousands of particles explode from the collision point of two relativistic (100 GeV per nucleon) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ... Quantum field theory (QFT) is the quantum theory of fields. ... Condensed matter physics is the field of physics that deals with the macroscopic physical properties of matter. ... Atomic, molecular, and optical physics is the study of matter-matter and light-matter interactions on the scale of single atoms or structures containing a few atoms. ...