In science and engineering, a conductor is a material which contains moveable electric charges. Science (from the Latin scientia, meaning " Knowledge " or "knowing" is the effort to discover, and increase human understanding Electrical engineering, sometimes referred to as electrical and electronic engineering, is a field of Engineering that deals with the study and application of Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction. In metallic conductors, such as copper or aluminum, the movable charged particles are electrons( See electrical conduction). Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 WikipediaNaming The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J Electrical conduction is the movement of electrically charged particles through a Transmission medium ( Electrical conductor) Positive charges may also be mobile in the form of atoms or ions, such as in the electrolyte of a battery. History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny 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 An electrolyte is any substance containing free Ions that behaves as an electrically conductive medium In electronics a battery is a combination of two or more Electrochemical cells which store chemical Energy which can be converted into electrical energy
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Note: The following applies to direct current only. Direct current ( DC) is the unidirectional flow of Electric charge. When the direction of voltage/current alternates, other effects (inductance and capacitance) come into play also. 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.
All conductors contain electric charges which will move when an electric potential difference (measured in volts) is applied across separate points on the material. Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction. The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force. This flow of charge (measured in amperes) is what is meant by electric current. In most materials, the rate of current is proportional to the voltage (Ohm's law,) provided the temperature remains constant and the material remains in the same shape and state. Ohm's law applies to Electrical circuits it states that the current through a conductor between two points is directly proportional to the The ratio between the voltage and the current is called the resistance (measured in ohms) of the object between the points where the voltage was applied. The resistance across a standard mass (and shape) of a material at a given temperature is called the resistivity of the material. Electrical resistivity (also known as specific electrical resistance) is a measure of how strongly a material opposes the flow of Electric current. The inverse of resistance and resistivity is conductance and conductivity. Some good examples of conductors are metal.
Most familiar conductors are metallic. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across Copper is the most common material for electrical wiring, and gold for high-quality surface-to-surface contacts. However, there are also many non-metallic conductors, including graphite, solutions of salts, and all plasmas. The Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. A salt, in Chemistry, is defined as the product formed from the neutralisation reaction of Acids and bases. In Physics and Chemistry, plasma is an Ionized Gas, in which a certain proportion of Electrons are free rather than being bound See electrical conduction for more information on the physical mechanism for charge flow in materials. Electrical conduction is the movement of electrically charged particles through a Transmission medium ( Electrical conductor)
Non-conducting materials lack mobile charges, and so resist the flow of electric current, generating heat. In fact, all materials offer some resistance and warm up when a current flows. Thus, proper design of an electrical conductor takes into account the temperature that the conductor needs to be able to endure without damage, as well as the quantity of electrical current. The motion of charges also creates an electromagnetic field around the conductor that exerts a mechanical radial squeezing force on the conductor. The electromagnetic field is a physical field produced by electrically charged objects. A conductor of a given material and volume (length x cross-sectional area) has no real limit to the current it can carry without being destroyed as long as the heat generated by the resistive loss is removed and the conductor can withstand the radial forces. This effect is especially critical in printed circuits, where conductors are relatively small and close together, and inside an enclosure: the heat produced, if not properly removed, can cause fusing (melting) of the tracks. Printed Circuit is the pseudonym for Claire Broadley an artist from Leeds Yorkshire who makes electronic pop music
Since all conductors have some resistance, and all insulators will carry some current, there is no theoretical dividing line between conductors and insulators. However, there is a large gap between the conductance of materials that will carry a useful current at working voltages and those that will carry a negligible current for the purpose in hand, so the categories of insulator and conductor do have practical utility.
Thermal and electrical conductivity often go together (for instance, most metals are both electrical and thermal conductors). However, some materials are practical electrical conductors without being a good thermal conductor.
Power engineering
In power engineering, a conductor is a piece of metal used to conduct electricity, known colloquially as an electrical wire. Power engineering, also called power systems engineering, is a subfield of Electrical engineering that deals with the generation, transmission Electrical wiring in general refers to insulated conductors used to carry Electricity, and associated devices
Conductor size
In many countries, conductors are measured by their cross section in square millimeters.
However, in the United States, conductors are measured by American wire gauge for smaller ones, and circular mils for larger ones. American wire gauge ( AWG) also known as the Brown & Sharpe wire gauge, is a standardized Wire gauge system used since 1857 predominantly A circular mil is a unit of Area, equal to the area of a Circle with a Diameter of one mil. In some poor countries they have overloaded wires going into one circuit.
Conductor materials
Of the metals commonly used for conductors, copper, has a high conductivity. Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Electrical conductivity or specific conductivity is a measure of a material's ability to conduct an Electric current. Silver is more conductive, but due to cost it is not practical in most cases. Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen However, it is used in specialized equipment, such as satellites, and as a thin plating to mitigate skin effect losses at high frequencies. This article is about artificial satellites For natural satellites also known as moons see Natural satellite. The skin effect is the tendency of an alternating electric current (AC to distribute itself within a conductor so that the current density near the surface of the Because of its ease of connection by soldering or clamping, copper is still the most common choice for most light-gauge wires. Soldering is a process in which two or more Metal items are joined together by melting and flowing a filler metal into the joint the filler metal having a relatively low
Conductor voltage
The voltage on a conductor is determined by the connected circuitry and has nothing to do with the conductor itself. Electrical tension (or voltage after its SI unit, the Volt) is the difference of electrical potential between two points of an electrical Conductors are usually surrounded by and/or supported by insulators and the insulation determines the maximum voltage that can be applied to any given conductor. An insulator, also called a Dielectric, is a material that resists the flow of Electric current.
Voltage of a conductor "V" is given by
- V = IR
where
- I is the current, measured in amperes
- V is the potential difference measured in volts
- R is the resistance measured in ohms
Conductor ampacity
The ampacity of a conductor, that is, the amount of current it can carry, is related to its electrical resistance: a lower-resistance conductor can carry more current. The ampere, in practice often shortened to amp, (symbol A is a unit of Electric current, or amount of Electric charge per second In Physics, the potential difference or pd between two points is the difference of the points' Scalar potential, equivalent to the line integral The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force. 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 The ohm (symbol Ω) is the SI unit of Electrical impedance or in the Direct current case Electrical resistance, American wire gauge ( AWG) also known as the Brown & Sharpe wire gauge, is a standardized Wire gauge system used since 1857 predominantly Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. The resistance, in turn, is determined by the material the conductor is made from (as described above) and the conductor's size. For a given material, conductors with a larger cross-sectional area have less resistance than conductors with a smaller cross-sectional area.
For bare conductors, the ultimate limit is the point at which power lost to resistance causes the conductor to melt. Aside from fuses, most conductors in the real world are operated far below this limit, however. In Electronics and Electrical engineering a fuse (short for fusible link) is a type of Overcurrent protection device For example, household wiring is usually insulated with PVC insulation that is only rated to operate to about 60 °C, therefore, the current flowing in such wires must be limited so that it never heats the copper conductor above 60 °C, causing a risk of fire. Fire is the heat and light energy released during a Chemical reaction, in particular a combustion reaction. Other, more expensive insulations such as Teflon or fiberglass may allow operation at much higher temperatures. Teflon is a Registered trademark and Brand name of the DuPont company for products made from three types of fluorine-containing polymers ( Fluoropolymers Fiberglass (also called fibreglass and glass fibre see Spelling differences) is material made from extremely fine Fibers of Glass.
The American wire gauge article contains a table showing allowable ampacities for a variety of copper wire sizes. American wire gauge ( AWG) also known as the Brown & Sharpe wire gauge, is a standardized Wire gauge system used since 1857 predominantly
Isotropy
If an electric field is applied to a material, and the resulting induced electric current is in the same direction, the material is said to be an isotropic electrical conductor. 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 current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. If the resulting electric current is in a different direction from the applied electric field, the material is said to be an anisotropic electrical conductor!.
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References
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