1. Different physical properties:
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(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.
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(2) The conductive properties of semiconductors at room temperature are between conductors and insulators.
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(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.
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2. Different uses:
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(1) Conductors are often used in engineering technology, science and energy fields.
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(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.
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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. However, wires touching each other can cause short circuits and fires.
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In coaxial cables, the central conductor must be located in the middle to prevent the reflection of electromagnetic waves. In addition, any voltage higher than 60V poses a risk of electric shock or shock to the human body. Using insulators as exterior cladding can prevent these problems.