Resistor Component Chain-Guanfa Technology will tell you what are the factors that affect the resistivity of copper wires today? What is the resistivity of copper wire? The formula for calculating the resistivity of copper wire.
There are several factors that affect the resistivity of copper wires:
1. Copper content (copper wire generally has a copper content of more than 99%, oxygen-free copper has a higher copper content), different materials have different resistivity, so the more impurities (the performance is generally worse than copper), the greater the resistivity.
2. The degree of annealing of the copper wire itself (good annealing degree and low resistivity).
3. The copper wire itself is in a state of preservation (if the copper wire is oxidized, the resistivity will increase).
4. If the resistivity when the converted temperature is 20 degrees, then the temperature will also affect the resistivity (the higher the temperature, the greater the resistivity).
The formula for calculating the resistivity of copper wire.
1. The first way to calculate the resistivity of copper wire:
The resistivity is calculated as: =rs l
is resistivity – the common unit ·m
s is the cross-sectional area – the commonly used unit m2
r is the resistance value – a common unit
l is the length of the wire - the common unit m
2. The second way to calculate the resistivity of copper wire:
Another formula for calculating resistivity is: =e j
is resistivity: the common unit is ·mm2 m
e is the electric field strength: the commonly used unit n c
j is the current density: the common unit is a m2
e,j can be vectors).
Additional Note on Copper Wire Resistivity:
1. Resistivity is not only related to the material of the conductor, but also to the temperature of the conductor. In the range where the temperature does not change much: the resistivity of almost all metals varies linearly with temperature, i.e. = o(1+at). where t is the temperature in Celsius, o is the resistivity at o, and a is the temperature coefficient of resistivity.
2. Since the resistivity changes with the change of temperature, the physical state of the resistance of some electrical appliances must be stated. For example, the resistance of a 220V-100W electric light filament is 484 ohms when it is powered on, and only about 40 ohms when it is not powered on.
3. Resistivity and resistance are two different concepts, resistivity reflects the properties of the substance to the current resistance, and resistance reflects the ability of the object to the current resistance.
4. The DC resistivity of a superconductor suddenly disappears at a certain low temperature, which is called the zero resistance effect. Superconductors have no electrical resistance.
Now that we know the resistivity of copper wires, let's take a look at the resistivity of other metals:
1. Silver 165;10-8
2. Aluminum 283;10-8
3. Tungsten 548;10-8
4. Iron 978;10-8
5. Platinum 222;10-7
6. Manganese copper 44;10-7
7. Mercury 96;10-7
8. Constantan 50;10-7
9. Nichrome alloy 10;10-6
10. Iron-chromium-aluminum alloy 14;10-6
11. Alconel alloy 16;10-6
12. graphite (8 13); 10-6。
What are the factors that affect the resistivity of copper wires? What is the resistivity of copper wire? If you want to know more about the knowledge of the calculation formula of copper wire resistivity, you can pay attention to Guanfa Technology, if you need to know more about the relevant technical knowledge of resistor components, please leave a message to get!