Why current leads to a greater resistance

In summary, current causes an increase in the resistance of a metal wire due to the increased vibrations of atoms caused by collisions with electrons. In contrast, in a semi-conductor, the increase in temperature promotes electrons to the conduction band, resulting in a decrease in resistance due to an increase in available charge carriers.
  • #1
nokia8650
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Why does current cause an increase in the resistance of a metal wire? Is the below explanation sound?:

As current flows, electrons collide into the atoms of the wire. This causes them to vibrate with a greater amplitude, increasing the temperature. The increased vibration of the atoms results in electrons colliding with the atoms more frequently, increasing the resistance.

Conversely, in a semi-conductor (eg. silicon), the increased temperature causes electrons to be promoted to the conduction band, increasing the number of electrons available for conduction, decreasing resistance since there are more charge carriers per unit volume.

Thanks
 
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  • #2
Sounds about right to me :approve:
 
  • #3
for your question. I can provide a response to the content you have shared. The explanation provided is generally sound, but there are a few additional factors that should be considered.

First, it is important to note that resistance in a metal wire is primarily due to the collisions between electrons and the atoms of the wire. As current flows through the wire, the electrons are constantly moving and colliding with the atoms, which creates resistance. The more frequent and intense these collisions are, the higher the resistance will be.

Secondly, the increase in temperature due to the collisions also plays a role in resistance. As the atoms vibrate with a greater amplitude, they become more difficult for the electrons to pass through, resulting in an increase in resistance.

In addition, the type of metal used in the wire can also affect resistance. Some metals have a higher number of free electrons available for conduction, which can result in lower resistance. On the other hand, some metals have a higher number of atoms, making it more difficult for the electrons to pass through, resulting in higher resistance.

Regarding the explanation for semi-conductors, it is true that the increase in temperature can cause electrons to be promoted to the conduction band, resulting in a decrease in resistance. However, it is also important to note that in semi-conductors, the number of free electrons available for conduction can also be controlled by doping, which is the intentional addition of impurities to the material. This can further decrease resistance in semi-conductors.

In conclusion, current leads to a greater resistance in metal wires due to the collisions between electrons and atoms, as well as the increase in temperature. The type of metal used and intentional doping in semi-conductors can also affect resistance.
 

Related to Why current leads to a greater resistance

1. Why does current lead to a greater resistance?

Current leads to a greater resistance because as the current increases, the number of collisions between electrons and atoms in the material also increases. This leads to more resistance as the electrons have a harder time moving through the material.

2. What is the relationship between current and resistance?

The relationship between current and resistance is inverse, meaning that as current increases, resistance decreases and vice versa. This is known as Ohm's Law and is represented by the equation R = V/I, where R is resistance, V is voltage, and I is current.

3. How does temperature affect resistance in a current?

Temperature affects resistance in a current because as the temperature of a material increases, the atoms in the material vibrate more, causing more collisions with electrons. This results in an increase in resistance.

4. What factors can impact the resistance of a material?

The factors that can impact the resistance of a material include its physical properties such as length, cross-sectional area, and temperature. The type of material also plays a role, as some materials have a higher resistance than others due to their atomic structure.

5. Can resistance ever be eliminated in a current?

No, resistance cannot be completely eliminated in a current. However, it can be reduced by using materials with lower resistance, increasing the cross-sectional area of the material, or decreasing the length of the material. Superconductors are the only materials that have zero resistance, but they require extremely low temperatures to maintain this property.

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