An **electromagnetic field** (also **EMF** or **EM field**) is a physical field produced by moving electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction. It is one of the four fundamental forces of nature (the others are gravitation, the weak interaction, and the strong interaction).

The field can be viewed as the combination of an electric field and a magnetic field. The electric field is produced by stationary charges, and the magnetic field by moving charges (currents); these two are often described as the sources of the field. The way in which charges and currents interact with the electromagnetic field is described by Maxwell's equations and the Lorentz force law.

From a classical perspective, the electromagnetic field can be regarded as a smooth, continuous field, propagated in a wavelike manner; whereas from the perspective of quantum field theory, the field is seen as quantized, being composed of individual particles.

Read more about Electromagnetic Field: Structure of The Electromagnetic Field, Dynamics of The Electromagnetic Field, Electromagnetic Field As A Feedback Loop, Mathematical Description, Relation To and Comparison With Other Physical Fields, Health and Safety

### Other articles related to "electromagnetic, electromagnetic field, electromagnetic fields, fields, field":

... General relativity modifies the description of

**electromagnetic**phenomena by employing a new version of Maxwell's equations ... in curved spacetime are (in cgs units) where Fab is the

**electromagnetic field**tensor representing the

**electromagnetic field**and Ja is a four-current representing the sources of the

**electromagnetic field**... The effect of an

**electromagnetic field**on a charged object is then modified to , where q is the charge on the object, m is the rest mass of the object and P a is ...

**Electromagnetic Field**

... The

**electromagnetic field**is a covariant antisymmetric tensor of rank 2 which can be defined in terms of the

**electromagnetic**potential by To see that this equation is invariant, we transform ... Using the antisymmetry of the

**electromagnetic field**one can either reduce to an identity (0 = 0) or render redundant all the equations except for those ... The covariant derivative of the

**electromagnetic field**is where Γαβ γ is the Christoffel symbol which is symmetric in its lower indices ...

**Electromagnetic Field**- Health and Safety

... The potential effects of

**electromagnetic fields**on human health vary widely depending on the frequency and intensity of the

**fields**... the health effects due to specific parts of the

**electromagnetic**spectrum, see the following articles Static electric

**fields**see Electric shock Static magnetic

**fields**see MRI#Safety Extremely low frequency (ELF) see ...

... the generator to get a current, which typically causes the wire coil to build up a large

**electromagnetic field**... Usually, this kind of

**electromagnetic field**creates an effect called the back electromotive force (back EMF) due to Lenz's law ... the back EMF was boosting the magnetic

**fields**used by the motor to generate electrical energy and cause acceleration ...

... Maxwell had studied and commented on the

**field**of electricity and magnetism as early as 1855/6 when "On Faraday's lines of force" was read to the Cambridge Philosophical Society ... at King's College, Maxwell calculated that the speed of propagation of an

**electromagnetic field**is approximately that of the speed of light ... the equations predict the existence of waves of oscillating electric and magnetic

**fields**that travel through empty space at a speed that could be predicted ...

### Famous quotes containing the word field:

“You cannot go into any *field* or wood, but it will seem as if every stone had been turned, and the bark on every tree ripped up. But, after all, it is much easier to discover than to see when the cover is off. It has been well said that “the attitude of inspection is prone.” Wisdom does not inspect, but behold.”

—Henry David Thoreau (1817–1862)