differ in
First, different definitions.
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1, usually the resistivity of the small (resistivity range of about 0.01~1 mm\/m), good conductive objects called conductors. Silver, copper and aluminum are good conductors.
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2, the resistivity is very large (the range of resistivity is about 10~10 ohms · mm\/m), the electrical conductivity is very poor objects called insulators. For example, ceramics, mica, glass, rubber, plastic, bakelite, paper, cotton yarn, resin and other objects, as well as dry wood are insulators (also called dielectrics).
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3, semiconductor (semiconductor), refers to the conductivity at room temperature between the conductor (conductor) and the insulator (insulator) materials. For example: silicon, germanium, selenium, copper oxide, etc., semiconductors are more and more widely used in the field of electronic technology.
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Second, different uses.
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1, conductors are often used in electrochemical industry, such as electrolytic purification, electroplating, etc. Conductors that do not cause chemical changes in the conduction process and do not have significant material transfer, such as metals, are called \"first class conductors.\"
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2, semiconductor can be used to measure temperature, temperature range can reach production, life, medical health, scientific research and teaching and other applications of 70% of the field.
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With high accuracy and stability, the resolution can reach 0.1 ° C, or even 0.01 ° C is not impossible, the linearity is 0.2%, and the temperature measurement range is -100~ 300 ° C, which is a cost-effective temperature measurement element.
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3, the insulator is usually used as the outer coating of the cable. In fact, air itself is an insulator and does not need other substances to insulate it. High-voltage power lines are insulated by air because it is not practical to use a solid (such as plastic) coating.
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However, wires touching each other can cause short circuits and fires. In coaxial cables, the central conductor must be located in the middle to prevent the reflection of electromagnetic waves.
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Three, different characteristics.
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1, the conductor increases the temperature, the resistance increases, the temperature decreases, the resistance decreases. At absolute zero, some conductors become superconductors when their resistance becomes zero.
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2, the semiconductor temperature increases, the resistance decreases, the temperature decreases, the resistance increases.
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3, the characteristics of the insulator is that the positive and negative charges in the molecule are bound very tightly, the charged particles that can move freely are very few, and the resistivity is very large, about 10 ~ 10 ohms · meters, so in general, the macroscopic current formed by the free charge movement under the action of the external electric field can be ignored, and it is considered to be a non-conductive substance.
1. Different physical properties:
(1) Conductor resistivity is small and easy to conduct current. There are a large number of freely moving charged particles in the conductor. Under the action of the external electric field, the charged particles move in a directional manner and form an obvious current.
(2) The conductive properties of semiconductors at room temperature are between conductors and insulators.
(3) The insulator is not good at conducting current, and the resistivity is extremely high. Insulator and conductor, there is no absolute boundary. An insulator can be converted into a conductor under certain conditions.
2. Different uses:
(1) Conductors are often used in engineering technology, science and energy fields.
(2) Semiconductors are used in integrated circuits, consumer electronics, communication systems, photovoltaic power generation, lighting, high-power power conversion and other fields, such as diodes are devices made of semiconductors.
(3) The insulator is usually used as the outer coating of the cable. In fact, air itself is an insulator and does not need other substances to insulate it. High-voltage power lines are insulated by air because it is not practical to use a solid (such as plastic) coating. However, wires touching each other can cause short circuits and fires.
Conductors, semiconductors, and insulators are all categories of basic substances in physics, and the most obvious differences between them are conductance and insulation properties. Conductors have very high conductivity and can be guided by current bands, while insulators are objects in which electrons cannot move, which has excellent insulation properties. The semiconductor is located between the two, it has the dual characteristics of conductivity and insulation ability, can control and adjust the current through itself, is the key component of today's wired communications, electronic computers and many other modern electronic equipment.
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The most important feature of the conductor is that the resistance is very low, the conductivity is very high, as long as the current is introduced to it, it will drive the electrons to achieve a good conductive effect. The characteristic of the insulator is that it can inhibit the transmission of current, as long as the strength of the potential is enough, it can resist the passage of current, and thus ensure that the circuit is not interfered with. The semiconductor is the combination of these two characteristics, it can achieve its own electrical energy excitation, and is not affected by the external current.
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Therefore, we can summarize the differences between conductors, semiconductors, and insulators:
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(1) Conductors have extremely high conductivity, while insulators and semiconductors have good insulation;
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2. Conductors can be guided by current bands, while insulators can resist the passage of current, and semiconductors can stimulate themselves without being affected by external current;
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(3) Conductors can conduct electron conduction, insulators can block the flow of electrons, and semiconductors can control the conduction of electrons according to external conditions.