electro-, electr-, electri-

(Greek > Latin: electric, electricity; from amber, resembling amber, generated from amber which when rubbed vigorously [as by friction], produced the effect of static electricity)

Electronics in our lives consists of numerous tools

Equipment which we use everyday relies on electronics to function including calculators, car controls, cameras, washing machines, medical scanners, mobile telephones, radar systems, computers; as well as many other applications or devices which are listed in this unit.

electromagnetic propulsion
1. Any form of rocket propulsion possessing both magnetic and electric properties; especially, one in which the propellant is accelerated by an electromagnetic field.

Specifically, such power in a flight vehicle generated by the electromagnetic acceleration of a plasma fluid.

2. Motive power for flight vehicles produced by electromagnetic acceleration of a plasma fluid.
electromagnetic pulse, EMP
1. A broadband, high-intensity, and short-duration burst of electromagnetic energy resulting from a nuclear explosion.
2. An electromagnetic reaction of large magnitude resulting from a thermonuclear explosion.
3. The pulse of electromagnetic radiation generated by a large thermonuclear explosion.
4. A powerful form of radiation released by a nuclear explosion, which has the effect of disrupting or disabling the electronically operated missile systems of a country.
electromagnetic pump
1. A device that moves conducive liquid through a pipe by sending current through the liquid.

Used in a nuclear reactor cooling system for liquid alkali metal circulation.

2. A pump in which a conductive liquid is made to move through a pipe by sending a large current transversely through the liquid.

Such a current reacts with a magnetic field which is at right angles to the pipe and to the current flow in order to move the current-carrying liquid conductor just as a solid conductor is moved in an electric motor.

electromagnetic radiation
1. The emission and propagation of radiation associated with a periodically varying electric and magnetic field traveling at the speed of light.

Types include gamma radiation, X-rays, ultraviolet, visible, and infrared radiation, and radar and radio waves.

2. Radiation that is produced with a combination of magnetic and electric forces.

It exists as a continuous spectrum of radiation, from that with the highest energy level and the shortest wavelength (gamma rays) to that with the lowest energy and longest wavelength (long radio waves).

All forms of electromagnetic radiation travel at the speed of light.

Light, radio waves, and X-rays are forms of electromagnetic radiation. Almost all of our knowledge of extraterrestrial objects comes from emitted or reflected electromagnetic radiation (visible light or radio waves).

electromagnetic reconnaissance
1. The emission and propagation of radiation associated with a periodically varying electric and magnetic field traveling at the speed of light, including gamma gray X-rays, and ultraviolet, light, infrared, and radio waves.
2. A reconnaissance activity for the purpose of locating and identifying potentially hostile transmitters of electromagnetic radiation, including radar, communication, missile-guidance, and navigation-aid equipment.

Identification generally includes determination of frequency, type of modulation, pulse data, antenna characteristics, and bearing to the transmitter.

electromagnetic relay
1. A switch that opens and closes contacts by the action of an electromagnetic element.
2. A relay in which current flow through a coil produces a magnetic field that results in contact actuation.
3. A device that opens or closes contacts by settling "moving" contacts against "fixed" contacts when current passes through an electromagnet.

The electric current sets up a magnetic attraction between the core of the electromagnet and a hinged arm to the tip of which is attached the "moving" contact.

The movement of the arm towards the core of the electromagnet brings "moving" and "fixed" contacts together.

When an electric current is withdrawn, a spring returns the arm to to its original position and the contacts separate.

electromagnetic repulsion
The repelling action between like poles of electromagnets.
electromagnetic rocket, electromagnetic-rocket engine, plasma rocket
1. A rocket that is accelerated by means of a plasma engine or an electrical-reaction engine in which magnetically accelerated plasma is used as the propellant.
2. An engine for space travel in which neutral plasma is accelerated and directed by external magnetic fields that interact with the magnetic field produced by electric current flow through the plasma.

The term plasma in these definitions refers to a gas-like state of matter consisting of positively charged ions, free electrons, and neutral particles.

Plasma is found in the stars, the sun, the solar wind, in lightning, and in fire.

electromagnetic sensitivity, EMF Sensitivity (s); electromagnetic sensitivities (pl), EMF Sensitivities (nouns)
An illness caused by radiation coming from cell phones, microwave or cell phone towers, radar, satellite, infrared, Wifi, GPS, RFID tags, computers, power lines, and other electrical equipment: "Individuals who are badly affected with EMF sensitivity suffer with headaches, insomnia, irritability, behavior disorders, autism, nerve and/or muscle pain, leukemia, tumors or cancer, heart attacks and other ailments."

"Certain population groups that have a tendency to suffer from elecromagnetic sensitivities include children, the elderly, and people with other illnesses."

"EMF Sensitivity is a highly controversial field of medicine; so, finding treatment for this illness is difficult, if not impossible, apparently because medical authorities do not consider electromagnetic fields a cause of the sicknesses as claimed by patients."

electromagnetic separation
The separation of ions of varying mass by a combination of electric and magnetic fields.

In the most common application, an isotopic mixture of ions is produced by either electron bombardment of a gas or thermionic emission.

The ionized particles are accelerated and collimated (adjusted the line of sight) into a beam by a system of electrodes, and the beam is projected into a magnetic field where the paths of the ions depend on their mass-to-charge ratio.

electromagnetic separator
1. An instrument that separates ions of different mass by passing them through a combination of electric and magnetic fields.
2. A device in which ions of varying mass are separated by a combination of electric and magnetic fields.
electromagnetic shield
A metal screen or enclosure placed around circuits to reduce the effects of both electric and magnetic fields.

Electromagnetic fields are caused by motors, generators, relays, or devices whose operation dempends on alternating fields.

Shielding is achieved by a reflection or absorption of fields while reflection occurs at the surface, and it is not usually affected by shield thickness.

Absorption, however, occurs within the shield and it is highly dependent on the thickness of the shield.

electromagnetic shielding
1. A means of preventing two circuits from electromagnetically coupling by placing at lest one of the circuits in a grounded enclosure of magnetic conductive material.
2. A process, similar to electrostatic or magnetostatic shielding, for suppressing changing magnetic fields or electromagnetic radiation at a device.
3. Electromagnetic shielding is the process of limiting the penetration of electromagnetic fields into a space, by blocking them with a barrier made of conductive material that has the property of conducting an electric current.
electromagnetic shock wave
1. An intense electromagnetic wave resulting from the coincidence of several waves of different velocities in a nonlinear dispersive medium.
2. An electromagnetic wave of significant intensity that results when waves with different intensities propagate with different velocities in a nonlinear optical medium, and faster-traveling waves from a pulse of light catch up with preceding, slower traveling waves.
electromagnetic spectrum
1. The ordered sequence of all known forms of electromagnetic radiations, extending from the shortest cosmic rays through gamma rays, X-rays, ultraviolet radiation, visible radiation, and infrared radiation, and including microwaves and all other wavelengths of radio energy.
2. The entire range of different types of electromagnetic waves, extending from the very long, low-frequency radio waves, through infrared and light waves, to the very short, high-frequency cosmic rays and X-rays which can be generated physically.

This range of electromagnetic wavelengths extends almost from zero to infinity and includes the visible portion of the spectrum known as light.

3. A list, chart, graph, or diagram showing the relationships among all known types or range of electromagnetic radiation including the range of frequencies and wavelengths.
4. The total range of wavelengths, extending from the shortest to the longest wavelength or conversely, that can be generated physically.

This range of electromagnetic wavelengths extends practically from zero to infinity and includes the visible portion of the spectrum known as light.

The references or sources of information for compiling the words and definitions in this unit are listed at this Electronic Bibliography page or specific sources are indicated when they are appropriate.

A cross reference of word units that are related, directly and/or indirectly, with "electricity": galvano-; hodo-; ion-; piezo-; -tron; volt; biomechatronics, info; mechatronics, info.