Copper wires are more conductive than aluminium wires?

In summary, copper wires are considered better conductors than aluminium wires because of their lower resistance to electricity. This means that less energy is converted into heat when the same amount of electricity passes through a copper wire compared to an aluminium wire. The resistivity of copper is also lower than that of aluminium, resulting in a lower resistance for the same quantity of wire. This is why aluminium wires require a larger cross-sectional area to carry the same amount of current as copper wires. Additionally, aluminium has a tendency to expand more than copper when heated, leading to potential connection issues. These factors make copper a more preferable choice for wiring, despite its higher cost.
  • #1
kthouz
193
0
Why do they say that copper wires are more conductor than aluminium wires?
 
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  • #2
Copper conducts electricity better than Aluminium, it has a lower resistance - that is less energy is converted into heat when passing the same amount of electricity through a Copper than Al wire.
 
  • #3
1 dm^3 of copper has less resistance than 1 dm^2 of Al.
1 Kg of Cu has more resistance than 1 Kg of Al.
1 $ of Cu has about the same resistance than 1 $ of Al. ( at prices when the books I read were written )
 
  • #4
The quantity you need to pay attention to is resistivity. As mgb points out it gives you a lower resistance for copper when compared to the same quantity of aluminum. I don't have the numbers in front of me, but aluminum wire requires about 50% more cross-sectional area to carry the same current as copper. If you are familiar with wire gauges, aluminum must be 2 gauges larger than copper. The great problem is that wire heats up when carrying current (I^2R losses) and aluminum expands much more than copper, thus loosening connections. Furthermore, aluminum oxide forms quite easily and is very non-conducting. My house originally had aluminum wiring due to the high price of copper when the Chilean copper mines were shut down in the early 1970s. After 2 fires, I had the house rewired with copper.
 

1. How does the conductivity of copper compare to aluminium?

Copper is a more conductive material than aluminium, meaning that it allows electricity to pass through it more easily. This is due to the atomic structure of copper, which allows for the free movement of electrons.

2. Why are copper wires preferred for electrical wiring?

Copper wires are preferred for electrical wiring because of their high conductivity. This means that less energy is lost when electricity passes through the wire, making it more efficient for powering devices and buildings.

3. Are there any advantages to using aluminium wires over copper wires?

While copper wires may have higher conductivity than aluminium wires, there are still some advantages to using aluminium in certain applications. Aluminium is lighter, cheaper, and more abundant than copper, making it a popular choice for overhead power lines.

4. What factors affect the conductivity of copper and aluminium wires?

The conductivity of copper and aluminium wires can be affected by several factors, including temperature, material purity, and wire thickness. Higher temperatures can decrease conductivity, while impurities in the metal can also hinder the flow of electricity.

5. Can copper and aluminium wires be used interchangeably?

In general, copper and aluminium wires cannot be used interchangeably because of their different conductivity levels. However, in some cases, aluminium wires can be substituted for copper wires, but it may require adjustments to the electrical system to account for the difference in conductivity.

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