# Portal:Electronics

## The Electronics Portal

The field of electronics comprises the study and use of systems that operate by controlling the flow of electrons (or other charge carriers) in devices such as thermionic valves and semiconductors. The design and construction of electronic circuits to solve practical problems is an integral technique in the field of electronics engineering and is equally important in hardware design for computer engineering. All applications of electronics involve the transmission of either information or power.

Consumer electronics are electronic devices intended for consumer use. Consumer electronics usually find applications in entertainment, communications and office productivity. Consumer electronics are manufactured throughout the world, although there is a particularly high concentration of manufacturing activity in the Far East. One overriding characteristic of all consumer electronic products is the trend of ever-falling prices. This is driven by gains in manufacturing efficiency and automation, coupled with improvements in semiconductor design.

## Selected biography

Michael Faraday, FRS (September 22, 1791 – August 25, 1867) was an English chemist and physicist who contributed significantly to the fields of electromagnetism and electrochemistry. He established that magnetism could affect rays of light and that there was an underlying relationship between the two phenomena. It was largely due to his efforts that electricity became viable for use in technology. The SI unit of capacitance, the farad, is named after him, as is the Faraday constant, the charge on a mole of electrons (about 96,485 coulombs). Faraday's law of induction states that a magnetic field changing in time creates a proportional electromotive force.

## Selected picture

Credit: Corps of Engineers

## News

November 19, 2008 The European Organization for Nuclear Research (CERN) said that repairing the Large Hadron Collider (LHC) will cost up to 16.6 million or US\$21 million. More...

April 30, 2008

HP Labs announces the creation of a Memristor, the fourth basic element of electronic circuits with the Resistor, Capacitor, and Inductor.

December 4, 2007

On the third day of the 2007 Taipei IT Month in Taiwan yesterday, notebook computers and desktop computers built with AMD's Phenom processor and Intel Penryn processor openly battled for the consumer-market after each company launched their quad core processors. More...

February 27, 2007

The new South Pole Telescope has recently collected its first light in a long-term project to learn about the nature of dark energy. More...

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## Consumer showcase

The iMac is a desktop computer designed and built by Apple Inc. It has been a cornerstone of Apple's Macintosh line of personal computers since its introduction in 1998, and has evolved through three distinct forms, all adhering to an "all-in-one" design ethos. The machine enjoys a relatively high profile in popular culture due to its distinctive aesthetics and Apple's successful marketing. The new 24" Core 2 Duo iMacs received CNET's "Must-have desktop" in their Top 10 Holiday Gift Picks.

## Selected article

Inductance is a measure of the amount of magnetic flux produced for a given electric current. The term was coined by Oliver Heaviside in February 1886. The SI unit of inductance is the henry (symbol: H), in honour of Joseph Henry. The symbol L is used for inductance, possibly in honour of the physicist Heinrich Lenz.

The inductance has the following relationship:

$L= \frac{\Phi}{i}$

where; L is the inductance in henrys, i is the current in amperes, Φ is the magnetic flux in webers. Strictly speaking, the quantity just defined is called self-inductance, because the magnetic field is created solely by the conductor that carries the current.

When a conductor is coiled upon itself N number of times around the same axis (forming a solenoid), the current required to produce a given amount of flux is reduced by a factor of N compared to a single turn of wire. Thus, the inductance of a coil of wire of N turns is given by:

$L= \frac{\lambda}{i} = N\frac{\Phi}{i}$

where, $\lambda$ is the total 'flux linkage'.