What is the cause of resistance?

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    Cause Resistance
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Discussion Overview

The discussion revolves around the concept of electrical resistance in conductors, specifically addressing the nature of collisions between free electrons and ions, the mechanisms behind resistance, and the production of heat due to resistance. It includes theoretical considerations and interpretations of physical phenomena.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Mr V questions the meaning of "collision" in the context of electrons and ions, wondering if electrons can truly collide with ions and what type of collision this would be.
  • Some participants suggest that the thermal motion of ions is a primary source of electron scattering, contributing to resistance.
  • Mr V expresses confusion about the concept of interference and requests further clarification and resources.
  • One participant proposes that thinking of electrons and ions as waves may help in understanding the interference effects mentioned in the context of resistance.
  • Another participant confirms that electrons do collide with ions and lose kinetic energy, which is converted to thermal energy, but reframes friction as "electrical friction" related to the lattice structure of ions.
  • Mr V raises a question about whether friction is the main cause of heat production due to resistance, leading to a discussion about the role of electrical friction instead.

Areas of Agreement / Disagreement

Participants express various interpretations of the collision process and the mechanisms of resistance, indicating that multiple competing views remain. The discussion does not reach a consensus on the nature of collisions or the primary causes of heat production in resistive materials.

Contextual Notes

There are unresolved questions regarding the definitions of collisions, the nature of energy loss, and the relationship between friction and electrical resistance. The discussion reflects a range of assumptions and interpretations that are not fully clarified.

Mr Virtual
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Hello again
My textbook states that: "Resistance of a given conductor is due to the collisions of free electrons with the ions or atoms of the conductor while drifting towards the positive end of the conductor."

What is meant by "collision" here? If we think deeply, can the free electrons actually "collide" with the ions? If so, then what sort of collision is this? What do they collide with- electrons of the ion? If I say that the electrons decelerate while traveling because of the attraction exerted by the positively charged ions, am I wrong? Stronger the attractive force, more will be the deceleration.
Secondly, why is heat produced due to resistance? One could say that due to decelaration, kinetic energy is converted to heat energy. But isn't friction the main cause for this conversion? Is friction the real cause then, or what?


Awaiting your answers...

Mr V
 
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In a metal, the thermal motion of ions is the primary source of scattering of electrons (due to destructive interference of free electron wave on non-correlating potentials of ions) - thus the prime cause of metal resistance.

from wiki
 
Can you explain it in a little more detail?

Mr V
 
Mr Virtual, try thinking of the electrons and ions [of the lattice structure] as waves instead of particles. You should get a feel as to what that wiki article is talking about in terms of interference.
 
Oh no! Not this interference thing again. I have had enough already with the confusions of Double-Slit experiment.
OK, can I please get the link to that page in wiki?

Mr V
 
What is meant by "collision" here? If we think deeply, can the free electrons actually "collide" with the ions?
Yes.
If so, then what sort of collision is this?
I can't categorize this [do you mean like elastic or inelastic?], but the electrons lose their kinetic energy in the form of thermal energy.
What do they collide with- electrons of the ion?
Yes. ions of the lattice structure.
If I say that the electrons decelerate while traveling because of the attraction exerted by the positively charged ions, am I wrong?
The localized effect of this is trivial.
Secondly, why is heat produced due to resistance? One could say that due to decelaration, kinetic energy is converted to heat energy. But isn't friction the main cause for this conversion? Is friction the real cause then, or what?
You answered your own question. But replace friction with "electrical friction", i.e ions of the lattice structure.
 
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