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What is resistivity?

Source: FAQ Editor: PingShang Click: Release time: 2019-09-24 11:49:26

Resistivity represents the physical quantity of substance that hinders electric current. Its size is related to temperature. The smaller the resistivity of the substance, the better the conductivity

Detailed explanation of resistivity:

1. The resistivity ρ is not only related to the material of the conductor, but also related to the temperature of the conductor. In the range of little temperature change: the resistivity of most metals changes linearly with temperature, that is, ρ=ρ0(1+at). In the formula, t is the temperature in degrees Celsius, ρ0 is the resistivity at 0°C, and a is the temperature coefficient of resistivity.

2. As the resistivity changes with temperature, the physical state of some electrical appliances must be explained. For example, the resistance of a 220 V -100 W electric lamp filament is 484 ohms when it is energized, and only about 40 ohms when it is not energized.

3. Resistivity is a physical quantity used to express the resistance characteristics of various materials. The ratio of the product of the resistance and the cross-sectional area of an original (20°C at room temperature) made of a certain substance to the length is called the resistivity of the substance. Resistivity has nothing to do with factors such as the length and cross-sectional area of the conductor. It is the electrical property of the conductor material itself, determined by the material of the conductor, and is related to external factors such as temperature, pressure, and magnetic field.

Regarding the question of what is resistivity, the editor of Ping Shang will introduce it to you today. If you can help, please contact us by email: smdmlcc@sina.com.

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