Electromagnetism

state of matter consisting of ionized gas

thumb|300x300px|Electromagnetic interactions are responsible for the glowing filaments in this plasma globe.

A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless particles that can only move at one speed, the speed of light measured in a vacuum. The photon belongs to the class of boson particles.

spatial distribution of vectors representing the force applied to a charged test particle

set of partial differential equations that describe how electric and magnetic fields are generated and altered by each other and by charges and currents

a physical law that states the electric force between two point charges is proportional to the product of the charges and inversely proportional to the square of the distance between them.

physical field produced by electrically charged objects

foundational law of electromagnetism

force exerted on a charge in electromagnetic field

branch of theoretical physics that studies consequences of the electromagnetic forces between electric charges and currents

thumb|A simple electromagnet consisting of a coil of wire wrapped around an iron core. A core of ferromagnetic material like iron serves to increase the magnetic field created. The strength of the magnetic field generated is proportional to the amount of current through the winding.

scalar physical quantity homogeneous to a voltage, expressing the modulus of the force exerted on a charge in an electric field

important law of classical magnetism

relates the integrated magnetic field around a closed loop to the electric current passing through the loop

common mnemonic for understanding orientation of axes in three-dimensional space

stream of electrons observed in vacuum tubes

tendency of alternating current to have the greatest current density near the surface of a conductor

physical constant quantifying the strength of the electromagnetic interaction between elementary charged particles

thumb|Field lines of a point dipole of any type, electric, magnetic, acoustic, etc.

conservation law

physical constant defining the capability of an electric field to permeate a vacuum

theorem in vector calculus

thumb|upright=1.2|Negative-index metamaterial array configuration, which was constructed of copper [[split-ring resonators and wires mounted on interlocking sheets of fiberglass circuit board. The total array consists of 3×20×20 unit cells with overall dimensions of .]]

partial differential equation of elliptic type with broad utility in mechanical engineering and theoretical physics

electromagnetism

Used to determine direction of the coil

closed loop path containing a magnetic flux

Physical phenomenon

generalization of electric charge (EM) adding color charge (QCD), mass-energy (gravitation), etc.; sometimes considered same as its charge quantum number

A quadrupole or quadrapole is one of a sequence of configurations of things like electric charge or current, magnetic fields, or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure reflecting various orders of complexity.

partial differential equation used in physics

mathematical object that describes the electromagnetic field in spacetime

physical constant relating the magnitudes of the electric and magnetic fields of electromagnetic radiation travelling through free space

expression for the dielectric constant of a material in terms of the atomic polarizability of the material’s constituent atoms/molecules

relativistic vector field

physical phenomenon of electron resonance

physical quantity

quantum mechanics taking into account particles near or at the speed of light

formula used to calculate the total power radiated by a non relativistic point charge as it accelerates

symmetric second-order tensor

In special and general relativity, the four-current (technically the four-current density) is the four-dimensional analogue of the current density, with the dimension of electric charge per time per area. Also known as vector current, it is used in the context of four-dimensional spacetime, rather than separating time from three-dimensional space. It is a four-vector and is Lorentz covariant.

application of an external magnetic field to a ferromagnet

oscillating electric and/or magnetic field that does not propagate as an electromagnetic wave but whose energy is spatially concentrated in the vicinity of the source

calculation technique for classical electrostatics

magnetically induced current distortions resulting in increased effective resistance of a conductor

path integral of the fluid velocity around a closed curve

incomplete, Lorentz-invariant gauge condition setting the four-divergence of the electromagnetic four-potential to zero

solution for electric field and magnetic field due to a distribution of moving electric charges and electric current in space

numerical methods for solving partial differential equations

electron trajectories in electromagnetic fields

complex measure of the attenuation (real part) and phase angle (imaginary part) along the path travelled by a plane wave

ways of writing the laws of classical electromagnetism in a form that is manifestly invariant under Lorentz transformations, in the formalism of special relativity using rectilinear inertial coordinate systems

type of clutch

heating using radio waves

measure of a dielectric material's inherent dissipation of electromagnetic energy

interpretation of electrodynamics

physics thought experiment

broadband electromagnetic impulse

Computation method named after Paul Peter Ewald