Lightning is one of the most prominent effects of electricity

Electricity (from New Latin ēlectricus, "amber-like") is a general term that encompasses a variety of phenomena resulting from the presence and flow of electric charge. The term New Latin or Neo-Latin is used to describe a form the Latin language used between the end of the Medieval Latin period (c Amber is Fossil tree Resin, which is appreciated for its color and beauty Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction. These include many easily recognizable phenomena such as lightning and static electricity, but in addition, less familiar concepts such as the electromagnetic field and electromagnetic induction. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or For the science of static charges see Electrostatics Static electricity refers to the accumulation of excess Electric charge in a The electromagnetic field is a physical field produced by electrically charged objects. Faraday's law of induction describes an important basic law of electromagnetism which is involved in the working of Transformers Inductors and many forms of

In general usage, the word 'electricity' is adequate to refer to a number of physical effects. However, in scientific usage, the term is vague, and these related, but distinct, concepts are better identified by more precise terms:

• Electric charge – a property of some subatomic particles, which determines their electromagnetic interactions. Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction. A subatomic particle is an elementary or composite Particle smaller than an Atom. In Physics, the electromagnetic force is the force that the Electromagnetic field exerts on electrically charged particles Electrically charged matter is influenced by, and produces, electromagnetic fields.
• Electric current – a movement or flow of electrically charged particles, typically measured in amperes. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. The ampere, in practice often shortened to amp, (symbol A is a unit of Electric current, or amount of Electric charge per second
• Electric field – an influence produced by an electric charge on other charges in its vicinity. 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 (that can
• Electric potential – the capacity of an electric field to do work, typically measured in volts. 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 In Thermodynamics, work is the quantity of Energy transferred from one system to another without an accompanying transfer of Entropy. The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force.
• Electromagnetism – a fundamental interaction between the electric field and the presence and motion of electric charge. Electromagnetism is the Physics of the Electromagnetic field: a field which exerts a Force on particles that possess the property of In Physics, a fundamental interaction or fundamental force is a mechanism by which particles interact with each other and which cannot be explained in terms

Electricity has been studied since antiquity, though scientific advances were not forthcoming until the seventeenth and eighteenth centuries. It would remain however until the late nineteenth century that engineers were able to put electricity to industrial and residential use, a time which witnessed a rapid expansion in the development of electrical technology. Electrical engineering, sometimes referred to as electrical and electronic engineering, is a field of Engineering that deals with the study and application of Electricity's extraordinary versatility as a source of energy means it can be put to an almost limitless set of applications which include transport, heating, lighting, communications, and computation. In Thermodynamics, motive power is an agency as Water or Steam, used to impart motion. HVAC (pronounced either "H-V-A-C" or occasionally " H-vak " is an Initialism or Acronym that stands for " Heating A lamp is a replaceable component such as an Incandescent light bulb, which is designed to produce Light from Electricity. Computation is a general term for any type of Information processing. The backbone of modern industrial society is, and for the foreseeable future can be expected to remain, the use of electrical power. ^[1]

History

Thales, the earliest researcher into electricity

Main article: History of electricity

See also: Etymology of electricity

That certain objects such as rods of amber could be rubbed with cat's fur and attract light objects like feathers was known to ancient cultures around the Mediterranean. In Physics the term quantity of Electricity refers to the quantity of Electric charge. Amber is Fossil tree Resin, which is appreciated for its color and beauty Thales of Miletos conducted a series of experiments into static electricity around 600 BC, from which he believed that friction rendered amber magnetic, in contrast to minerals such as magnetite, which needed no rubbing. Thales of Miletus According to Bertrand Russell, "Philosophy begins with Thales For the science of static charges see Electrostatics Static electricity refers to the accumulation of excess Electric charge in a In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. Magnetite is not to be confused with Magnesite or Maghemite. Magnetite is a ferrimagnetic Mineral with chemical ^[2][3] Thales was incorrect in believing the attraction was due to a magnetic effect, but later science would prove a link between magnetism and electricity.

A controversial claim is made that the Parthians had some knowledge of electroplating, based on the 1936 discovery of the Baghdad Battery, which resembles a galvanic cell, though this claim lacks evidence supporting the exact nature of the artifact, and whether it was electrical in nature. Parthia ( Middle Persian: اشکانیان Ashkâniân) was an Iranian civilization situated in the northeastern part of modern Iran Electroplating is the process of using electrical current to reduce Cations of a desired material from a solution and coat a conductive object The Baghdad Battery is the common name for a number of artifacts created in Mesopotamia, possibly during the Parthian or Sassanid period (the early The Galvanic cell, named after Luigi Galvani, consists of two different metals connected by a Salt bridge or a porous disk between the individual half-cells ^[4]

Several ancient writers, such as Pliny the Elder and Scribonius Largus, attested to the numbing effect of electric shocks delivered by catfish and torpedo rays, and knew that such shocks could travel along conducting objects. Gaius or Caius Plinius Secundus, ( AD 23 – August 25, AD 79 better known as Pliny the Elder, was an ancient Author Scribonius Largus was the court Physician to the Roman emperor Claudius. "Electrocute" redirects here For the band see Electrocute (band. Electric catfish is the common name for the Catfish ( order Siluriformes family Malapteruridae. Electric rays (order Torpediniformes) are Fish that have a rounded body and a pair of organs capable of producing an Electric discharge, varying ^[5] Patients suffering from ailments such as gout or headache were directed to touch electric fish in the hope that the powerful jolt might cure them. Gout (also called metabolic arthritis) is a disease created by a buildup of Uric acid. A headache ( cephalalgia in medical terminology is a condition of pain in the Head; sometimes Neck or upper back pain may also be interpreted ^[6]

Benjamin Franklin conducted extensive research on electricity in the 18th century

Electricity would remain little more than an intellectual curiosity for over two millennia until 1600, when the English physician William Gilbert made a careful study of electricity and magnetism, distinguishing the lodestone effect from static electricity produced by rubbing amber. William Gilbert, also known as Gilbard ( Colchester, England, May 24, 1544 &ndash London, England, November 30 Lodestone or loadstone refers to either Magnetite, a Magnetic Mineral form of iron(II, Iron(III oxide ^[2] He coined the New Latin word electricus ("of amber" or "like amber", from ηλεκτρον [elektron], the Greek word for "amber") to refer to the property of attracting small objects after being rubbed. The term New Latin or Neo-Latin is used to describe a form the Latin language used between the end of the Medieval Latin period (c ^[7] This association gave rise to the English words "electric" and "electricity", which made their first appearance in print in Thomas Browne's Pseudodoxia Epidemica of 1646. Sir Thomas Browne ( October 19, 1605 &ndash October 19, 1682) was an English author of varied works which disclose his wide learning Sir Thomas Browne 's vast work refuting the common errors and superstitions of his age Pseudodoxia Epidemica, first appeared in 1646 and went through five subsequent ^[8]

Further work was conducted by Otto von Guericke, Robert Boyle, Stephen Gray and C. F. du Fay. Otto von Guericke (originally spelled Gericke ˈgeːʁɪkə ( November 20, 1602 &ndash May 11, 1686 ( Julian calendar) Robert Boyle was a Natural philosopher, chemist physicist inventor and early Gentleman scientist, noted for his work in Physics and Chemistry Charles François de Cisternay du Fay (Paris 14 September[[ 698]] &ndash 1739 was a French Chemist and superintendent of the Jardin du Roi. In the 18th century, Benjamin Franklin conducted extensive research in electricity, selling his possessions to fund his work. Benjamin Franklin ( April 17 1790 was one of the Founding Fathers of the United States of America. In June 1752 he is reputed to have attached a metal key to the bottom of a dampened kite string and flown the kite in a storm-threatened sky. ^[9] He observed a succession of sparks jumping from the key to the back of his hand, showing that lightning was indeed electrical in nature. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or ^[10]

In 1791 Luigi Galvani published his discovery of bioelectricity, demonstrating that electricity was the medium by which nerve cells passed signals to the muscles. Luigi Galvani was an Italian Physician and Physicist who lived and died in Bologna. Bioelectromagnetism (sometimes equated with bioelectricity) refers to the electrical magnetic or Electromagnetic fields produced by living cells tissues Neurons (ˈnjuːɹɒn also known as neurones and nerve cells) are responsive cells in the Nervous system that process and transmit information ^[11] Alessandro Volta's battery, or voltaic pile, of 1800, made from alternating layers of zinc and copper, provided scientists with a more reliable source of electrical energy than the electrostatic machines previously used. Count Alessandro Giuseppe Antonio Anastasio Volta was a Lombard physicist known especially for the development of the first electric cell in A voltaic pile is a set of individual Voltaic cells placed in series An electrostatic generator, or electrostatic machine, is a mechanical device that produces Static electricity, or electricity at High voltage ^[11] André-Marie Ampère discovered the relationship between electricity and magnetism in 1820; Michael Faraday invented the electric motor in 1821, and Georg Ohm mathematically analysed the electrical circuit in 1827. André-Marie Ampère (20 January 1775 &ndash 10 June 1836 was a French Physicist and Mathematician who is generally credited as one of the main discoverers Michael Faraday, FRS ( September 22 1791 – August 25 1867) was an English An electric motor uses Electrical energy to produce Mechanical energy. Georg Simon Ohm' was a German physicist As a high school teacher Ohm began his research with the recently invented Electrochemical cell, invented by Italian Count ^[11]

While it had been the early nineteenth century that had seen rapid progress in electrical science, the late nineteenth century would see the greatest progress in electrical engineering. Electrical engineering, sometimes referred to as electrical and electronic engineering, is a field of Engineering that deals with the study and application of Through such people as Nikola Tesla, Thomas Edison, George Westinghouse, Ernst Werner von Siemens, Alexander Graham Bell and Lord Kelvin, electricity was turned from a scientific curiosity into an essential tool for modern life, becoming a driving force for the Second Industrial Revolution. There have already been discussions about Tesla's ethnicity on the talk page George Westinghouse Jr ( 6 October 1846 &ndash 12 March 1914) was an American Entrepreneur and Engineer Ernst Werner von Siemens (known as Werner von Siemens) ( December 13, 1816 &ndash December 6, 1892) was a German Inventor WikipediaWikiProject Aircraft. Please see WikipediaWikiProject Aircraft/page content for recommended layout William Thomson 1st Baron Kelvin (or Lord Kelvin) OM, GCVO, PC, PRS, FRSE, (26 June 1824 &ndash 17 December 1907 The Second Industrial Revolution, typically dated between 1870 and 1914 was a second phase of the Industrial Revolution, involving several developments within the chemical ^[12]

Concepts

Electric charge

Main article: Electric charge

See also: electron, proton, and ion

Electric charge is a property of certain subatomic particles, which gives rise to and interacts with, the electromagnetic force, one of the four fundamental forces of nature. Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge A subatomic particle is an elementary or composite Particle smaller than an Atom. In Physics, the electromagnetic force is the force that the Electromagnetic field exerts on electrically charged particles In Physics, a fundamental interaction or fundamental force is a mechanism by which particles interact with each other and which cannot be explained in terms Charge originates in the atom, in which its most familiar carriers are the electron and proton. History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive It is a conserved quantity, that is, the net charge within an isolated system will always remain constant regardless of any changes taking place within that system. In Physics, a conservation law states that a particular measurable property of an isolated Physical system does not change as the system evolves In the Natural sciences an isolated system, as contrasted with a open system, is a Physical system that does not interact with its Surroundings ^[13] Within the system, charge may be transferred between bodies, either by direct contact, or by passing along a conducting material, such as a wire. ^[14] The informal term static electricity refers to the net presence (or 'imbalance') of charge on a body, usually caused when dissimilar materials are rubbed together, transferring charge from one to the other. For the science of static charges see Electrostatics Static electricity refers to the accumulation of excess Electric charge in a

Charge on a gold-leaf electroscope causes the leaves to visibly repel each other

The presence of charge gives rise to the electromagnetic force: charges exert a force on each other, an effect that was known, though not understood, in antiquity. An electroscope is an early Scientific instrument that is used to detect the presence and magnitude of Electric charge on a body In Physics, a force is whatever can cause an object with Mass to Accelerate. ^[15] A lightweight ball suspended from a string can be charged by touching it with a glass rod that has itself been charged by rubbing with a cloth. If a similar ball is charged by the same glass rod, it is found to repel the first: the charge acts to force the two balls apart. Two balls that are charged with an rubbed amber rod also repel each other. However, if one ball is charged by the glass rod, and the other by an amber rod, the two balls are found to attract each other. These phenomena were investigated in the late eighteenth century by Charles-Augustin de Coulomb, who deduced that charge manifests itself in two opposing forms, leading to the well-known axiom: like-charged objects repel and opposite-charged objects attract. Charles Augustin de Cock (June 14 1736 Angoulême France – August 23 1806 Penis France was a French Physicist. ^[15]

The force acts on the charged particles themselves, hence charge has a tendency to spread itself as evenly as possible over a conducting surface. The magnitude of the electromagnetic force, whether attractive or repulsive, is given by Coulomb's law, which relates the force to the product of the charges and has an inverse-square relation to the distance between them. ---- Bold text Coulomb's law', developed in the 1780s by French physicist Charles Augustin de Coulomb, may be stated in scalar form In Physics, an inverse-square law is any Physical law stating that some physical Quantity or strength is inversely proportional ^[16][17] The electromagnetic force is very strong, second only in strength to the strong interaction,^[18] but unlike that force it operates over all distances. In particle physics the strong interaction, or strong force, or color force, holds Quarks and Gluons together to form Protons and ^[19] In comparison with the much weaker gravitational force, the electromagnetic force pushing two electrons apart is 10⁴² times that of the gravitational attraction pulling them together. Newton 's law of universal Gravitation is a physical law describing the gravitational attraction between bodies with mass Gravitation is a natural Phenomenon by which objects with Mass attract one another ^[20]

The charge on electrons and protons is opposite in sign, hence an amount of charge may be expressed as being either negative or positive. By convention, the charge carried by electrons is deemed negative, and that by protons positive, a custom that originated with the work of Benjamin Franklin. Benjamin Franklin ( April 17 1790 was one of the Founding Fathers of the United States of America. ^[21] The amount of charge is usually given the symbol Q and expressed in coulombs;^[22] each electron carries the same charge of approximately −1. The coulomb (symbol C) is the SI unit of Electric charge. It is named after Charles-Augustin de Coulomb. 6022×10⁻¹⁹ coulomb. The coulomb (symbol C) is the SI unit of Electric charge. It is named after Charles-Augustin de Coulomb. The proton has a charge that is equal and opposite, and thus +1. 6022×10⁻¹⁹  coulomb. Charge is possessed not just by matter, but also by antimatter, each antiparticle bearing an equal and opposite charge to its corresponding particle. Matter is commonly defined as being anything that has mass and that takes up space. In Particle physics and Quantum chemistry, antimatter is the extension of the concept of the Antiparticle to Matter, where antimatter is composed to most kinds of particles, there is an associated antiparticle with the same Mass and opposite Electric charge. ^[23]

Charge can be measured by a number of means, an early instrument being the gold-leaf electroscope, which although still in use for classroom demonstrations, has been superseded by the electronic electrometer. An electroscope is an early Scientific instrument that is used to detect the presence and magnitude of Electric charge on a body An electrometer is an electrical instrument for measuring Electric charge or electrical Potential difference. ^[14]

Electric current

Main article: Current (electricity)

The movement of electric charge is known as an electric current, the intensity of which is usually measured in amperes. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. The ampere, in practice often shortened to amp, (symbol A is a unit of Electric current, or amount of Electric charge per second Current can consist of any moving charged particles; most commonly these are electrons, but any charge in motion constitutes a current.

By historical convention, a positive current is defined as having the same direction of flow as any positive charge it contains, or to flow from the most positive part of a circuit to the most negative part. Current defined in this manner is called conventional current. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. The motion of negatively-charged electrons around an electric circuit, one of the most familiar forms of current, is thus deemed positive in the opposite direction to that of the electrons. An electrical network is an interconnection of Electrical elements such as Resistors Inductors Capacitors Transmission lines Voltage ^[24] However, depending on the conditions, an electric current can consist of a flow of charged particles in either direction, or even in both directions at once. In Physics, a charged particle is a particle with an Electric charge. The positive-to-negative convention is widely used to simplify this situation. If another definition is used—for example, "electron current"—it needs to be explicitly stated.

An electric arc provides an energetic demonstration of electric current

The process by which electric current passes through a material is termed electrical conduction, and its nature varies with that of the charged particles and the material through which they are travelling. An electric arc is an Electrical breakdown of a gas which produces an ongoing plasma discharge, resulting from a current flowing through normally nonconductive Electrical conduction is the movement of electrically charged particles through a Transmission medium ( Electrical conductor) Examples of electric currents include metallic conduction, where electrons flow through a conductor such as metal, and electrolysis, where ions (charged atoms) flow through liquids. In Science and engineering, a conductor is a material which contains movable Electric charges. In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny While the particles themselves can move quite slowly, sometimes with a average drift velocity only fractions of a millimetre per second,^[14] the electric field that drives them itself propagates at close to the speed of light, enabling electrical signals to pass rapidly along wires. The drift velocity is the average Velocity that a particle such as an Electron, attains due to an Electric field. 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 (that can ^[25]

Current causes several observable effects, which historically were the means of recognising its presence. That water could be decomposed by the current from a voltaic pile was discovered by Nicholson and Carlisle in 1800, a process now known as electrolysis. William Nicholson (1753&mdash May 21, 1815) was a renowned English chemist who was also a writer on natural philosophy and chemistry as well as a translator Sir Anthony Carlisle FRCS, FRS ( Stillington, England 15 February 1768 - London, 2 November 1842 In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current Their work was greatly expanded upon by Michael Faraday in 1833. Michael Faraday, FRS ( September 22 1791 – August 25 1867) was an English ^[26] Current through a resistance causes localised heating, an effect James Prescott Joule studied mathematically in 1840. Electrical resistance is a ratio of the degree to which an object opposes an Electric current through it measured in Ohms Its reciprocal quantity is James Prescott Joule FRS (ˈdʒuːl December 24, 1818 &ndash October 11, 1889) was an English Physicist ^[26] One of the most important discoveries relating to current was made accidentally by Hans Christian Ørsted in 1820, when, while preparing a lecture, he witnessed the current in a wire disturbing the needle of a magnetic compass. ^[27] He had discovered electromagnetism, a fundamental interaction between electricity and magnetics. Electromagnetism is the Physics of the Electromagnetic field: a field which exerts a Force on particles that possess the property of

In engineering or household applications, current is often described as being either direct current (DC) or alternating current (AC). Direct current ( DC) is the unidirectional flow of Electric charge. An alternating current ( AC) is an Electric current whose direction reverses cyclically as opposed to Direct current, whose direction remains constant These terms refer to how the current varies in time. Direct current, as produced by example from a battery and required by most electronic devices, is a unidirectional flow from the positive part of a circuit to the negative. In electronics a battery is a combination of two or more Electrochemical cells which store chemical Energy which can be converted into electrical energy Electronics refers to the flow of charge (moving Electrons through Nonmetal conductors (mainly Semiconductors, whereas electrical ^[28] If, as is most common, this flow is carried by electrons, they will be travelling in the opposite direction. Alternating current is any current that reverses direction repeatedly; almost always this takes the form of a sinusoidal wave. ^[29] Alternating current thus pulses back and forth within a conductor without the charge moving any net distance over time. The time-averaged value of an alternating current is zero, but it delivers energy in first one direction, and then the reverse. Alternating current is affected by electrical properties that are not observed under steady state direct current, such as inductance and capacitance. Steady state is a more general situation than Dynamic equilibrium. In Electrical circuits, any Electric current i produces a Magnetic field and hence generates a total Magnetic flux \Phi acting Capacitance is a measure of the amount of Electric charge stored (or separated for a given Electric potential. ^[30] These properties however can become important when circuitry is subjected to transients, such as when first energised. In Electrical engineering and Mechanical Engineering, a transient response or natural response is the response of a system to a change from equilibrium

Electric field

Main article: Electric field

See also: Electrostatics

The concept of the electric field was introduced by Michael Faraday. 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 (that can Electrostatics is the branch of Science that deals with the Phenomena arising from what seems to be stationary Electric charges Since Classical In Physics, a field is a Physical quantity associated to each point of Spacetime. Michael Faraday, FRS ( September 22 1791 – August 25 1867) was an English An electric field is created by a charged body in the space that surrounds it, and results in a force exerted on any other charges placed within the field. The electric field acts between two charges in a similar manner to the way that the gravitational field acts between two masses, and like it, extends towards infinity and shows an inverse square relationship with distance. Mass is a fundamental concept in Physics, roughly corresponding to the Intuitive idea of how much Matter there is in an object ^[19] However, there is an important difference. Gravity always acts in attraction, drawing two masses together, while the electric field can result in either attraction or repulsion. Since large bodies such as planets generally carry no net charge, the electric field at a distance is usually zero. Thus gravity is the dominant force at distance in the universe, despite being much the weaker. ^[20]

Field lines emanating from a positive charge above a plane conductor

An electric field generally varies in space,^[31] and its strength at any one point is defined as the force (per unit charge) that would be felt by a stationary, negligible charge if placed at that point. ^[32] The conceptual charge, termed a test charge, must be vanishingly small to prevent its own electric field disturbing the main field and must also be stationary to prevent the effect of magnetic fields. In Physics, a magnetic field is a Vector field that permeates space and which can exert a magnetic force on moving Electric charges As the electric field is defined in terms of force, and force is a vector, so it follows that an electric field is also a vector, having both magnitude and direction. In Physics, a force is whatever can cause an object with Mass to Accelerate. The magnitude of a mathematical object is its size a property by which it can be larger or smaller than other objects of the same kind in technical terms an Ordering Direction is the information contained in the relative position of one point with respect to another point without the Distance information Specifically, it is a vector field. In Mathematics a vector field is a construction in Vector calculus which associates a vector to every point in a (locally Euclidean space. ^[32]

The study of electric fields created by stationary charges is called electrostatics. Electrostatics is the branch of Science that deals with the Phenomena arising from what seems to be stationary Electric charges Since Classical The field may be visualised by a set of imaginary lines whose direction at any point is the same as that of the field. This concept was introduced by Faraday,^[33] whose term 'lines of force' still sometimes sees use. A line of force in Faraday 's extended sense is synonymous with Maxwell 's line of induction. The field lines are the paths that a point positive charge would seek to make as it was forced to move within the field; they are however an imaginary concept with no physical existence, and the field permeates all the intervening space between the lines. ^[33] Field lines emanating from stationary charges have several key properties: first, that they originate at positive charges and terminate at negative charges; second, that they must enter any good conductor at right angles, and third, that they may never cross nor close in on themselves. ^[34]

The principals of electrostatics are important when designing items of high-voltage equipment. The term high voltage characterizes electrical circuits in which the voltage used is the cause of particular safety concerns and insulation requirements There is a finite limit to the electric field strength that may withstood by any medium. Beyond this point, electrical breakdown occurs and an electric arc causes flashover between the charged parts. The term electrical breakdown has several similar but distinctly different meanings An electric arc is an Electrical breakdown of a gas which produces an ongoing plasma discharge, resulting from a current flowing through normally nonconductive Air, for example, tends to arc at electric field strengths which exceed 30 kV per centimetre across small gaps. Over larger gaps, its breakdown strength is weaker, perhaps 1 kV per centimetre. ^[35] The most visible natural occurrence of this is lightning, caused when charge becomes separated in the clouds by rising columns of air, and raises the electric field in the air to greater than it can withstand. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or The voltage of a large lightning cloud may be as high as 100 MV and have discharge energies as great as 250 kWh. ^[36]

The field strength is greatly affected by nearby conducting objects, and it is particularly intense when it is forced to curve around sharply pointed objects. This principal is exploited in the lightning conductor, the sharp spike of which acts to encourage the lightning stroke to develop there, rather than to the building it serves to protect. A lightning rod (USA or lightning conductor (UK is a single component in a Lightning protection system. ^[37]

Electric potential

Main article: Electric potential

See also: Voltage

A pair of AA cells. 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 Electrical tension (or voltage after its SI unit, the Volt) is the difference of electrical potential between two points of an electrical A AA battery (double a or /ˈdʌbəl eɪ/ is a dry cell-type battery commonly used in portable Electronic devices The + sign indicates the polarity of the potential differences between the battery terminals.

The concept of electric potential is closely linked to that of the electric field. A small charge placed within an electric field experiences a force, and to have brought that charge to that point against the force requires work. In Physics, mechanical work is the amount of Energy transferred by a Force. The electric potential at any point is defined as the energy required to bring a unit test charge from an infinite distance slowly to that point. Infinity (symbolically represented with ∞) comes from the Latin infinitas or "unboundedness It is usually measured in volts, and one volt is the potential for which one joule of work must be expended to bring a charge of one coulomb from infinity. The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force. The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity The coulomb (symbol C) is the SI unit of Electric charge. It is named after Charles-Augustin de Coulomb. ^[38] This definition of potential, while formal, has little practical application, and a more useful concept is that of electric potential difference, and is the energy required to move a unit charge between two specified points. In Physics, the potential difference or pd between two points is the difference of the points' Scalar potential, equivalent to the line integral An electric field has the special property that it is conservative, which means that the path taken by the test charge is irrelevant: all paths between two specified points expend the same energy, and thus a unique value for potential difference may be stated. A conservative force is defined as a Force with the following property when an object moves from one location to another the force changes the Potential energy of ^[38] The volt is so strongly identified as the unit of choice for measurement and description of electric potential difference that the term voltage sees greater everyday usage. Electrical tension (or voltage after its SI unit, the Volt) is the difference of electrical potential between two points of an electrical

For practical purposes, it is useful to define a common reference point to which potentials may be expressed and compared. While this could be at infinity, a much more useful reference is the Earth itself, which is assumed to be at the same potential everywhere. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 This reference point naturally takes the name earth or ground. In Electrical engineering, the term ground or earth has several meanings depending on the specific application areas In Electrical engineering, the term ground or earth has several meanings depending on the specific application areas Earth is assumed to be an infinite source of equal amounts of positive and negative charge, and is therefore electrically uncharged – and unchargeable. ^[39]

Electric potential is a scalar quantity, that is, it has only magnitude and not direction. It may be viewed as analogous to temperature: as there is a certain temperature at every point in space, and the temperature gradient indicates the direction and magnitude of the driving force behind heat flow, similarly, there is an electric potential at every point in space, and its gradient, or field strength, indicates the direction and magnitude of the driving force behind charge movement. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature In atmospheric sciences ( Meteorology, Climatology and related fields the temperature gradient (typically of air, more generally of any Fluid In thermal physics, heat transfer is the passage of Thermal energy from a hot to a colder body In Vector calculus, the gradient of a Scalar field is a Vector field which points in the direction of the greatest rate of increase of the scalar Equally, electric potential may be seen as analogous to height: just as a released object will fall through a difference in heights caused by a gravitational field, so a charge will 'fall' across the voltage caused by an electric field. Height is the measurement of vertical Distance, but has two meanings in common use ^[40]

The electric field was formally defined as the force exerted per unit charge, but the concept of potential allows for a more useful and equivalent definition: the electric field is the local gradient of the electric potential. Usually expressed in volts per metre, the vector direction of the field is the line of greatest gradient of potential. ^[14]

Electromagnetism

Main article: Electromagnetism

Magnetic field circles around a current

Ørsted's discovery in 1821 that a magnetic field existed around all sides of a wire carrying an electric current indicated that there was a direct relationship between electricity and magnetism. Electromagnetism is the Physics of the Electromagnetic field: a field which exerts a Force on particles that possess the property of In Physics, a magnetic field is a Vector field that permeates space and which can exert a magnetic force on moving Electric charges Moreover, the interaction seemed different from gravitational and electrostatic forces, the two forces of nature then known. The force on the compass needle did not direct it to or away from the current-carrying wire, but acted at right angles to it. ^[27] Ørsted's slightly obscure words were that "the electric conflict acts in a revolving manner. " The force also depended on the direction of the current, for if the flow was reversed, then the force did too. ^[41]

Ørsted did not fully understand his discovery, but he observed the effect was reciprocal: a current exerts a force on a magnet, and a magnetic field exerts a force on a current. The phenomenon was further investigated by Ampère, who discovered that two parallel current carrying wires exerted a force upon each other: two wires conducting currents in the same direction are attracted to each other, while wires containing current flowing in opposite directions are forced apart. André-Marie Ampère (20 January 1775 &ndash 10 June 1836 was a French Physicist and Mathematician who is generally credited as one of the main discoverers ^[42] The interaction is mediated by the magnetic field each current produces and forms the basis for the international definition of the ampere. The ampere, in practice often shortened to amp, (symbol A is a unit of Electric current, or amount of Electric charge per second ^[42]

The electric motor exploits an important effect of electromagnetism: a current flowing through a magnetic field experiences a force at right angles to both the field and current

This relationship between magnetic fields and currents is extremely important, for it led to Michael Faraday's invention of the electric motor in 1821. An electric motor uses Electrical energy to produce Mechanical energy. Faraday's homopolar motor consisted of a permanent magnet sitting in a pool of mercury. A homopolar motor has a Magnetic field along the axis of rotation and an electric current that at some point is not parallel to the magnetic field A magnet (from Greek grc μαγνήτης λίθος " Magnesian stone" is a material or object that produces a Magnetic field. Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum A current was allowed to flow through a wire suspended from a pivot above the magnet and dipped into the mercury. The magnet exerted a tangential force on the wire, making it circle around the magnet for as long as the current was maintained. ^[43]

Experimentation by Faraday in 1831 revealed that a wire moving perpendicular to a magnetic field developed a potential difference between its ends. Further analysis of this process, known as electromagnetic induction, enabled him to state the principal, now known as Faraday's law of induction, that the potential difference induced in a closed circuit is proportional to the rate of change of magnetic flux through the loop. Faraday's law of induction describes an important basic law of electromagnetism which is involved in the working of Transformers Inductors and many forms of Faraday's law of induction describes an important basic law of electromagnetism which is involved in the working of Transformers Inductors and many forms of Magnetic flux, represented by the Greek letter Φ ( Phi) is a measure of quantity of Magnetism, taking into account the strength and the extent of a Magnetic Exploitation of this discovery enabled him to invent the first electrical generator in 1831, in which he converted the mechanical energy of a rotating copper disc to electrical energy. In Electricity generation, an electrical generator is a device that converts Mechanical energy to Electrical energy, generally using Electromagnetic ^[43] Faraday's disc was inefficient and of no use as a practical generator, but it showed the possibility of generating electric power using magnetism, a possibility that would be taken up by those that followed on from his work. A homopolar generator is a DC Electrical generator that is made when a magnetic electrically conductive rotating disk has a different Magnetic field passing

Faraday's and Ampère's work showed that a time-varying magnetic field acted as a source of an electric field, and a time-varying electric field was a source of a magnetic field. Thus, when either field is changing in time, then a field of the other is necessarily induced. ^[44] Such a phenomenon has the properties of a wave, and is naturally referred to as an electromagnetic wave. A wave is a disturbance that propagates through Space and Time, usually with transference of Energy. Electromagnetic radiation takes the form of self-propagating Waves in a Vacuum or in Matter. Electromagnetic waves were analysed theoretically by James Clerk Maxwell in 1864. James Clerk Maxwell (13 June 1831 &ndash 5 November 1879 was a Scottish mathematician and theoretical physicist. Maxwell discovered a set of equations that could unambiguously describe the interrelationship between electric field, magnetic field, electric charge, and electric current. He could moreover prove that such a wave would necessarily travel at the speed of light, and thus light itself was a form of electromagnetic radiation. Maxwell's Laws, which unify light, fields, and charge are one of the great milestones of theoretical physics. In Classical electromagnetism, Maxwell's equations are a set of four Partial differential equations that describe the properties of the electric ^[44]

Electric circuits

Main article: Electric circuit

A basic electric circuit. An electrical network is an interconnection of Electrical elements such as Resistors Inductors Capacitors Transmission lines Voltage An electrical network is an interconnection of Electrical elements such as Resistors Inductors Capacitors Transmission lines Voltage The voltage source V on the left drives a current I around the circuit, delivering electrical energy into the resistance R. A voltage source is any device or system that produces an Electromotive force between its terminals OR derives a secondary voltage from a primary Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. Electric energy is the potential energy associated with the conservative Coulomb forces between Charged particles contained within a system, where Electrical resistance is a ratio of the degree to which an object opposes an Electric current through it measured in Ohms Its reciprocal quantity is From the resistor, the current returns to the source, completing the circuit.

An electric circuit is an interconnection of electric components, usually to perform some useful task, with a return path to enable the charge to return to its source.

The components in an electric circuit can take many forms, which can include elements such as resistors, capacitors, switches, transformers and electronics. |- align = "center"| |width = "25"| | |- align = "center"| || Potentiometer |- align = "center"| | | |- align = "center"| Resistor| | A capacitor is a passive electrical component that can store Energy in the Electric field between a pair of conductors A switch is a mechanical device used to connect and disconnect an electric Circuit at will A transformer is a device that transfers Electrical energy from one circuit to another through inductively coupled Electrical conductors Electronics refers to the flow of charge (moving Electrons through Nonmetal conductors (mainly Semiconductors, whereas electrical Electronic circuits contain active components, usually semiconductors, and typically exhibit non-linear behavior, requiring complex analysis. An electronic circuit is a closed path formed by the interconnection of Electronic components through which an Electric current can flow Passivity is a property of engineering systems most commonly used in electronic engineering and control systems A semiconductor' is a Solid material that has Electrical conductivity in between a conductor and an insulator; it can vary over that This article describes the use of the term nonlinearity in mathematics The simplest electric components are those that are termed passive and linear: while they may temporarily store energy, they contain no sources of it, and exhibit linear responses to stimuli. The word linear comes from the Latin word linearis, which means created by lines. ^[45]

The resistor is perhaps the simplest of passive circuit elements: as its name suggests, it resists the flow of current through it, dissipating its energy as heat. |- align = "center"| |width = "25"| | |- align = "center"| || Potentiometer |- align = "center"| | | |- align = "center"| Resistor| | Electrical resistance is a ratio of the degree to which an object opposes an Electric current through it measured in Ohms Its reciprocal quantity is Ohm's law is a basic law of circuit theory, stating that the current passing through a resistance is directly proportional to the potential difference across it. Ohm's law applies to Electrical circuits it states that the current through a conductor between two points is directly proportional to the Circuit theory is the theory of accomplishing work by means of routing matter through a loop. The ohm, the unit of resistance, was named in honour of Georg Ohm, and is symbolised by the Greek letter Ω. The ohm (symbol Ω) is the SI unit of Electrical impedance or in the Direct current case Electrical resistance, 1 Ω is the resistance that will produce a potential difference of one volt in response to a current of one amp. ^[45]

The capacitor is a device capable of storing charge, and thereby storing electrical energy in the resulting field. A capacitor is a passive electrical component that can store Energy in the Electric field between a pair of conductors Conceptually, it consists of two conducting plates separated by a thin insulating layer; in practice, thin metal foils are coiled together, increasing the surface area per unit volume and therefore the capacitance. Capacitance is a measure of the amount of Electric charge stored (or separated for a given Electric potential. The unit of capacitance is the farad, named after Michael Faraday, and given the symbol F: one farad is the capacitance that develops a potential difference of one volt when it stores a charge of one coulomb. This is about the capacitance unit of measure For the charge unit see Faraday (unit. Michael Faraday, FRS ( September 22 1791 – August 25 1867) was an English A capacitor connected to a voltage supply initially causes a current to flow as it accumulates charge; this current will however decay in time as the capacitor fills, eventually falling to zero. A capacitor will therefore not permit a steady state current to flow, but instead blocks it. Steady state is a more general situation than Dynamic equilibrium. ^[45]

The inductor is a conductor, usually a coil of wire, that stores energy in a magnetic field in response to the current flowing through it. An inductor is a passive electrical component designed to provide Inductance in a circuit When the current changes, the magnetic field does too, inducing a voltage between the ends of the conductor. Faraday's law of induction describes an important basic law of electromagnetism which is involved in the working of Transformers Inductors and many forms of The induced voltage is proportional to the time rate of change of the current. A time derivative is a Derivative of a function with respect to Time, usually interpreted as the Rate of change of the value of the function The constant of proportionality is termed the inductance. In Electrical circuits, any Electric current i produces a Magnetic field and hence generates a total Magnetic flux \Phi acting The unit of inductance is the henry, named after Joseph Henry, a contemporary of Faraday. The henry (symbol H is the SI unit of Inductance. It is named after Joseph Henry (1797-1878 the American scientist who discovered electromagnetic Joseph Henry ( December 17 1797 &ndash May 13 1878) was an American scientist who served as the first Secretary of the Smithsonian One henry is the inductance that will induce a potential difference of one volt if the current through it changes at a rate of one ampere per second. ^[45] The inductor's behaviour is in some regards converse to that of the capacitor: it will freely allow an unchanging current to flow, but opposes the flow of a rapidly changing one.

Production and uses

Generation

Main article: Electricity generation

Wind power is of increasing importance in many countries

Thales' experiments with amber rods were the first studies into the production of electrical energy. Electricity generation is the process of converting non-electrical Energy to Electricity. While this method, now known as the triboelectric effect, is capable of lifting light objects and even generating sparks, it is extremely inefficient. Triboelectric Series Materials are often listed in order of the polarity of charge separation when they are touched with another object ^[46] It was not until the invention of the voltaic pile in the eighteenth century that a viable source of electricity became available. The voltaic pile, and its modern descendant, the electrical battery, store energy chemically and make it available on demand in the form of electrical energy. In electronics a battery is a combination of two or more Electrochemical cells which store chemical Energy which can be converted into electrical energy ^[46] The battery is a versatile and very common power source which is ideally suited to many applications, but its energy storage is finite, and once discharged it must be disposed of or recharged. For large electrical demands electrical energy must be generated and transmitted in bulk.

Electrical energy is usually generated by electro-mechanical generators driven by steam produced from fossil fuel combustion, or the heat released from nuclear reactions; or from other sources such as kinetic energy extracted from wind or flowing water. In Electricity generation, an electrical generator is a device that converts Mechanical energy to Electrical energy, generally using Electromagnetic Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. Fossil fuels or mineral fuels are fossil source Fuels that is Hydrocarbons found within the top layer of the Earth’s crust. Nuclear Energy is released by the splitting (fission or merging together (fusion of the nuclei of Atom (s The kinetic energy of an object is the extra Energy which it possesses due to its motion Such generators bear no resemblance to Faraday's homopolar disc generator of 1831, but they still rely on his electromagnetic principle that a conductor linking a changing magnetic field induces a potential difference across its ends. ^[47] The invention in the late nineteenth century of the transformer meant that electricity could be generated at centralised power stations, benefiting from economies of scale, and be transmitted across countries with increasing efficiency. A transformer is a device that transfers Electrical energy from one circuit to another through inductively coupled Electrical conductors A power station (also referred to as generating station, power plant or powerhouse) is an industrial facility for the generation of Electric power transmission, a process in the delivery of Electricity to consumers is the bulk transfer of electrical power ^[48][49] Since electrical energy cannot easily be stored in quantities large enough to meet demands on a national scale, at all times exactly as much must be produced as is required. ^[48] This requires electricity utilities to make careful predictions of their electrical loads, and maintain constant co-ordination with their power stations. An electric utility is a company (often a Public utility) that engages in the generation, transmission, and distribution of electricity for sale A certain amount of generation must always be held in reserve to cushion an electrical grid against inevitable disturbances and losses. In power systems, the operating reserve is the generating capacity available to the system operator within a short interval of time to meet demand in case a generator

Demand for electricity grows with great rapidity as a nation modernises and its economy develops. The United States showed a 12% increase in demand during each year of the first three decades of the twentieth century,^[50] a rate of growth that is now being experienced by emerging economies such as those of India or China. ^[51][52] Historically, the growth rate for electricity demand has outstripped that for other forms of energy, such as coal. ^[53]

Environmental concerns with electricity generation have led to an increased focus on generation from renewable sources, in particular from wind- and hydropower. Modern technology uses large amounts of electrical power This is normally generated at Power plants which convert some other kind of energy into electrical power Renewable energy is Energy generated from Natural resources mdashsuch as Sunlight, Wind, Rain, tides and geothermal Wind Power is the conversion of wind energy into a useful form such as electricity using Wind turbines At the end of 2007 worldwide capacity of wind-powered generators was Hydropower, hydraulic power or water power is power that is derived from the Force or Energy of moving water which may While debate can be expected to continue over the environmental impact of different means of electricity production, its final form is relatively clean. ^[54]

Uses

The light bulb, an early application of electricity, operates by Joule heating: the passage of current through resistance generating heat

Electricity is an extremely flexible form of energy, and it may be adapted to a huge, and growing, number of uses. The incandescent light bulb, incandescent lamp or incandescent light globe is a source of electric Light that works by Incandescence, (a general Joule heating is the process by which the passage of an Electric current through a conductor releases Heat. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. Electrical resistance is a ratio of the degree to which an object opposes an Electric current through it measured in Ohms Its reciprocal quantity is ^[55] The invention of a practical incandescent light bulb in the 1870s led to lighting becoming one of the first publicly available applications of electrical power. The incandescent light bulb, incandescent lamp or incandescent light globe is a source of electric Light that works by Incandescence, (a general Lighting includes both artificial Light sources such as lamps and natural illumination of interiors from Daylight. Although electrification brought with it its own dangers, replacing the naked flames of gas lighting greatly reduced fire hazards within homes and factories. ^[56] Public utilities were set up in many cities targeting the burgeoning market for electrical lighting.

The Joule heating effect employed in the light bulb also sees more direct use in electric heating. Joule heating is the process by which the passage of an Electric current through a conductor releases Heat. Electric heating is any process in which electrical energy is converted to heat While this is versatile and controllable, it can be seen as wasteful, since most electrical generation has already required the production of heat at a power station. ^[57] A number of countries, such as Denmark, have issued legislation restricting or banning the use of electric heating in new buildings. ^[58] Electricity is however a highly practical energy source for refrigeration,^[59] with air conditioning representing a growing sector for electricity demand, the effects of which electricity utilities are increasingly obliged to accommodate. Refrigeration is the process of removing Heat from an enclosed space or from a substance and moving it to a place where it is unobjectionable The term air conditioning refers to the cooling and dehumidification of indoor air for Thermal comfort. ^[60]

Electricity is used within telecommunications, and indeed the electrical telegraph, demonstrated commercially in 1837 by Cooke and Wheatstone, was one of its earliest applications. The electrical telegraph is a telegraph that uses electric signals The electromagnetic telegraph is a device for human-to-human transmission Sir William Fothergill Cooke ( 4 May 1806 &ndash 25 June 1879) was with Charles Wheatstone, the co-inventor of the Cooke-Wheatstone Sir Charles Wheatstone FRS (6 February 1802 - 19 October 1875 was a British Scientist and Inventor of many scientific breakthroughs With the construction of first intercontinental, and then transatlantic, telegraph systems in the 1860s, electricity had enabled communications in minutes across the globe. The First Transcontinental Telegraph was a milestone in the formation of the United States. The first transatlantic Telegraph Cable crossed the Atlantic Ocean from Foilhommerum Valentia Island, in western Ireland to Optical fibre and satellite communication technology have taken a share of the market for communications systems, but electricity can be expected to remain an essential part of the process. An optical fiber (or fibre) is a Glass or Plastic fiber that carries Light along its length A communications satellite (sometimes abbreviated to comsat) is an artificial Satellite stationed in space for the purposes of Telecommunications.

The effects of electromagnetism are most visibly employed in the electric motor, which provides a clean and efficient means of motive power. An electric motor uses Electrical energy to produce Mechanical energy. A stationary motor such as a winch is easily provided with a supply of power, but a motor that moves with its application, such as an electric vehicle, is obliged to either carry along a power source such as a battery, or by collecting current from a sliding contact such as a pantograph, placing restrictions on its range or performance. A winch is a mechanical device that is used to pull in (wind up or let out (wind out or otherwise adjust the " Tension " of a Rope or Wire rope The Electric Vehicle was an American Automobile manufactured only in 1899 A pantograph is a device that collects electric current from Overhead lines for electric Trains or Trams The term stems from the resemblance to pantograph

Electronic devices make use of the transistor, perhaps one of the most important inventions of the twentieth century,^[61] and a fundamental building block of all modern circuitry. In Electronics, a transistor is a Semiconductor device commonly used to amplify or switch electronic signals A modern integrated circuit may contain several billion miniaturised transistors in a region only a few centimetres square. Microchipsjpg|right|thumb|200px|Microchips ( EPROM memory with a transparent window showing the integrated circuit inside ^[62]

Electricity and the natural world

Physiological effects

Main article: Electric shock

A voltage applied to a human body causes an electric current to flow through the tissues, and although the relationship is non-linear, the greater the voltage, the greater the current. "Electrocute" redirects here For the band see Electrocute (band. ^[63] The threshold for perception varies with the supply frequency and with the path of the current, but is about 1 mA for mains-frequency electricity. ^[64] If the current is sufficiently high, it will cause muscle contraction, fibrillation of the heart, and tissue burns. Fibrillation is the rapid irregular and unsynchronized contraction of the muscle fibers of the Heart. A burn is a type of Injury that may be caused by Heat, cold, Electricity, Chemicals, Light, Radiation, or ^[63] The lack of any visible sign that a conductor is electrified makes electricity a particular hazard. The pain caused by an electric shock can be intense, leading electricity at times to be employed as a method of torture. Torture, according to the United Nations Convention Against Torture, is "any act by which severe pain or suffering, whether physical or mental is intentionally Death caused by an electric shock is referred to as electrocution. Electrocution is still the means of judicial execution in some jurisdictions, though its use has become rarer in recent times. Capital punishment, the death penalty or execution, is the Killing of a person by judicial process as Punishment. ^[65]

Electrical phenomena in nature

The electric eel, Electrophorus electricus

Electricity is by no means a purely human invention, and may be observed in several forms in nature, a prominent manifestation of which is lightning. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or The Earth's magnetic field is thought to arise from a natural dynamo of circulating currents in the planet's core. Earth 's magnetic field (and the surface magnetic field) is approximately a Magnetic dipole, with one pole near the North pole (see The dynamo theory proposes a mechanism by which a celestial body such as the Earth generates a Magnetic field. ^[66] Certain crystals, such as quartz, or even sugarcane, generate a potential difference across their faces when subjected to external pressure. Quartz (from German) is the most abundant Mineral in the Earth 's Continental crust (although Feldspar is more common in Sugarcane ( Saccharum) is a genus of 6 to 37 species (depending on taxonomic interpretation of tall perennial grasses (family Poaceae tribe Andropogoneae ^[67] This phenomenon is known as piezoelectricity, from the Greek piezein, meaning to press, and was discovered in 1880 by Pierre and Jacques Curie. Piezoelectricity is the ability of some materials (notably Crystals and certain Ceramics including bone to generate an Electric potential in response to Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly Pierre Curie (15 May 1859 &ndash 19 April 1906 was a French physicist, a pioneer in Crystallography, Magnetism, Piezoelectricity Paul-Jacques Curie ( October 29, 1856 &ndash 1941 was a French Physicist and professor at the University of Montpellier. The effect is reciprocal, and when a piezoelectric material is subjected to an electric field, a small change in physical dimensions take place. ^[67]

Some organisms, such as sharks, are able to detect and respond to changes in electric fields, an ability known as electroreception,^[68] while others, termed electrogenic, are able to generate voltages themselves to serve as a predatory or defensive weapon. Sharks ( Superorder Selachimorpha) are a type of Fish with a full cartilaginous Skeleton and a highly streamlined body Electroreception, sometimes written as electroception, is the biological ability to perceive Electrical impulses It is particularly common among aquatic creatures ^[5] The order Gymnotiformes, of which the best known example is the electric eel, detect or stun their prey via high voltages generated from modified muscle cells called electrocytes. The Gymnotiformes is a lineage of Ostariophysan Teleost Electric fishes Common names found in the literature include the Neotropical electric The electric eel, Electrophorus electricus, is a species of Fish. The electric organ is a muscular organ common to all Electric fish used for the purposes of creating an Electric field; a behavior used for navigation ^[6][5] All animals transmit information along their cell membranes with voltage pulses called action potentials, whose functions include communication by the nervous system between neurons and muscles. In Neurophysiology, the action potential is a self-regenerating Wave of Electrochemical activity that allows Nerve cells to carry a signal ^[69] (Because of this principle, an electric shock can induce temporary or permanent paralysis by "overloading" the nervous system. Paralysed redirects here For other uses see xx Paralysed (disambiguation Paralysis is the complete loss of Muscle function ) They are also responsible for coordinating activities in certain plants. ^[69]

See also

• Electrical energy, the potential energy of a system of charges
• Electricity market, the sale of electrical energy
• Electrical phenomena, observable events which illuminate the physical principles of electricity
• Electric power, the rate at which electrical energy is transferred
• Electronics, the study of the movement of charge through certain materials and devices
• Hydraulic analogy, an analogy between the flow of water and electric current

References

Bibliography

• Bird, John (2007), Electrical and Electronic Principles and Technology, 3rd edition, Newnes, ISBN 0-978-8556-6 
• Duffin, W. J. (1980), Electricity and Magnetism, 3rd edition, McGraw-Hill, ISBN 007084111X 
• Edminister, Joseph (1965), Electric Circuits, 2nd Edition, McGraw-Hill, ISBN 07084397X 
• Hammond, Percy (1981), Electromagnetism for Engineers, Pergamon, ISBN 0-08-022104-1 
• Morely, A. & Hughes, E (1994), Principles of Electricity, Fifth edition, Longman, ISBN 0-582-22874-3 
• Naidu, M. S. & Kamataru, V. (1982), High Voltage Engineering, Tata McGraw-Hill, ISBN 0-07-451786-4 
• Nilsson, James & Riedel, Susan (2007), Electric Circuits, Prentice Hall, ISBN 978-0131989252 
• Patterson, Walter C. (1999), Transforming Electricity: The Coming Generation of Change, Earthscan, ISBN 185383341X 
• Sears, et al. , Francis (1982), University Physics, Sixth Edition, Addison Wesley, ISBN 0-2010-7199-1 

External links

• Illustrated view of how an American home's electrical system works
• Electricity around the world
• Electricity Misconceptions
• Electricity and Magnetism
• Understanding Electricity and Electronics in about 10 Minutes