conductor

[d ǎ o t ǐ]

Substance capable of conducting electric current

open 3 entries with the same name

Collection

zero Useful+1

zero

This entry is made by Compilation and application of scientific encyclopedia entries of "Science Popularization China" to examine.

Conductor refers to resistivity Small and easy Conducting current Substances. There are a lot of freely movable charged particle be called carrier 。 Out electric field Under the action, the carrier makes directional movement, forming an obvious current. Metal is the most common type of conductor. Metal atom Outermost valence electron It's easy to break away Nucleus And become free electron , left Positive ion （ Atomic particle ）Formation rule Of lattice 。 The concentration of free electrons in metal is very high, so the conductivity Usually larger than other conductor materials. The resistivity of metal conductor is generally temperature To decrease. At very low temperatures, some Metal And the resistivity of the alloy will disappear and be converted into“ Superconductor ”。

Chinese name: conductor
Foreign name: conductor
Discipline: Electromagnetism

Features: resistivity Small and easy Conducting current
Field: Engineering technology
Scope: energy

catalog

Class I conductor

Announce

edit

Metal And graphite are the most common type of conductors. In metals and graphite Nucleus and Inner electron constitute Atomic particle , regularly arranged into lattice , and Outer layer Of valence electron It is easy to break away from the atomic nucleus and become free electron , they constitute electric conduction The carrier of. The concentration of free electrons in metals and graphite is very high, about 10 per cubic centimeter twenty-two Therefore, metal and graphite resistivity Very small, conductivity Very big. Metallic and graphitic resistivity Is 10 －8 —10 －6 Ohm · m, generally decreases as the temperature decreases. Metal and graphite do not cause chemical reaction There is no significant material transfer, which is called the first type conductor.

Class II conductor

Announce

edit

electrolyte The solution of electrolyte The molten electrolyte of is also a conductor, and its carrier is Positive and negative ions 。 It is found that most pure liquids can dissociation , but the degree of dissociation is very small, so it is not a conductor. as pure water With resistivity up to 10 four Ohm, 10% higher than the resistivity of metal ten —10 twelve Times. But if a little electrolyte is added to pure water, Ion concentration The resistivity is greatly reduced and becomes a conductor. The resistivity of electrolyte is much higher than that of metal, because Carrier concentration It is much smaller than metal, and the force between ion and surrounding medium is larger, which makes it outside electric field The mobility in is also much smaller. electrolyte Accompanied by Chemical change , with substance transfer Is called the second type conductor. It is often used Electrochemical industry , such as electrolysis Purification electroplate Etc. The conductors, such as metal and graphite, which do not cause chemical changes and have no significant material transfer during the conduction process are called "the first type conductors".

Gas conductor

Announce

edit

ionization Is also conductive（ Gas conduction ）, of which carrier^[1] Is electronic and Positive and negative ions 。 Normally, Gas Is good insulator 。 With the help of the outside world reason , such as heating Or with X-ray 、 γ radial or ultraviolet rays Irradiation can make gas molecule The ionized gas becomes a conductor by dissociation. Ionized gas Conductivity It is greatly related to the applied voltage, and is often accompanied by Phonation 、 luminescence etc. physical process 。 Ionized gases are often used Electric light source Manufacturing industry. Gas under the action of external ionizing agent electric conduction It is called gas non Self-sustaining discharge 。 As the applied voltage increases, the current also increases. When the voltage increases to a certain value, the non self sustained discharge reaches saturated When the voltage continues to increase to a certain value, the current suddenly increases sharply. At this time, even if the ionizing agent is removed, the conductivity can still be maintained, and the gas will transition from non self-sustaining discharge to self-sustaining discharge. The characteristics of gas self-sustaining discharge depend on the type of gas pressure , electrode material, electrode shape, electrode temperature, distance between two electrodes and other factors. Self sustained discharge takes different forms under different conditions, including glow discharge 、 Arc discharge and corona discharge Etc. There are many practical applications of gas non self sustained discharge and self sustained discharge.^[2]

Other conductive media

Announce

edit

Electric insulator Also known as dielectric 。 Their resistivity is extremely high, 10% higher than that of metals fourteen Times more. Under certain external conditions (such as heating, heating high pressure Will be affected by“ breakdown ”, and convert it into conductor. The main electrical properties of insulators or dielectrics are reflected in conductance 、 polarization , loss and breakdown^[1] 。

Nowadays, for example germanium （Ge）、 silicon （ Si ） Such conductors are called semiconductors. Of this type of conductor resistivity It lies between metal and insulator, and decreases rapidly with the increase of temperature. A certain amount of free electron and hole , the latter can be regarded as having positive charge Of carrier 。 With metal or electrolyte The content of impurities in the semiconductor and the change of external conditions (such as light, temperature pressure Change, etc.), will make it Conductivity Can occur significantly change 。^[1]

Guide the electrical material to operate at a temperature close to Absolute zero The object Molecular thermal motion Lower material resistance The property of approaching 0. "Superconductor" refers to a conductive material capable of superconducting transmission.

Novice on the road

Growth task Getting Started with Editing Edit Rule Edit by myself

I have questions

Content query Online Service Official post bar Feedback

Complaints and suggestions

Report bad information Failed to appeal through entries Complaint of infringement information Blocking query and unblocking

Jinggong Network Anbei No. 1100000200001