Potential energy of an electron

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Discussion Overview

The discussion revolves around the potential energy of electrons in an electric circuit, specifically addressing how potential energy changes as electrons move through different potentials and resistances. Participants explore concepts related to electric potential, kinetic energy, and the behavior of electrons in circuits.

Discussion Character

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

Main Points Raised

  • Some participants propose that an electron's potential energy decreases when moving from lower to higher electric potential, while others clarify that this depends on the context of "potential."
  • There is a suggestion that when electrons pass through resistance, their potential energy decreases because they do work against the resistance, which is seen as a hindrance to their flow.
  • Concerns are raised about the kinetic energy of electrons, with some arguing that it should not be negligible due to the mass of the electron, while others assert that in typical circuits, the kinetic energy is indeed negligible due to low velocities.
  • Participants discuss the collective behavior of electrons, emphasizing that they cannot be treated as individual entities when considering potential energy changes.
  • Clarifications are made regarding the relationship between electric potential and potential energy, with some stating that the potential energy of an electron is defined as PE=-eU, indicating that it decreases when moving to a higher potential.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between electric potential and potential energy, as well as the significance of kinetic energy in this context. The discussion remains unresolved regarding the treatment of individual electrons versus collective behavior and the implications for potential energy changes.

Contextual Notes

Limitations include the dependence on definitions of electric potential and potential energy, as well as the assumptions regarding the negligible kinetic energy of electrons in typical circuits.

gracy
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.(1)Electron's potential energy decreases when it moves from lower to higher potential,right?And i also want to verify few more things on which i am doubtful .(2)Why when electron passes through resistance it's potential energy decreases?I think because it require energy to pass or cross resistance as it is hindrance for flow of electron so when electron crosses this it does work i.e uses energy that's why it's energy which was totally in the form of potential energy get reduced,so that's why when electron passes through resistance it's potential energy decreases.right?
(3)But why electron's energy is totally in the form of potential energy,as it was moving through circuit it should have kinetic energy also.Is kinetic energy negligible as mass of electron is very small .I don't think so it is right.And if it has kinetic energy, why after crossing resistance only it's potential energy decreases,why not kinetic energy decreases i.e why not electrons get slow down after crossing resistance?
Although i have put 3 questions together we can discuss one by one.Just guide me where i am wrong.
Regards.
 
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gracy said:
Electron's potential energy decreases when it moves from lower to higher potential,right?
Depends on what you mean. "Electric potential" - yes. "Potential for the electron" - no.
gracy said:
(2)Why when electron passes through resistance it's potential energy decreases?I think because it require energy to pass or cross resistance as it is hindrance for flow of electron so when electron crosses this it does work i.e uses energy that's why it's energy which was totally in the form of potential energy get reduced,so that's why when electron passes through resistance it's potential energy decreases.right?
Something in that direction, yes. It does not work (=ordered mechanical energy), however, it heats up the resistor.
gracy said:
(3)But why electron's energy is totally in the form of potential energy,as it was moving through circuit it should have kinetic energy also.Is kinetic energy negligible as mass of electron is very small
Kinetic energy is negligible as both [mass per charge] and velocity are very small. The net motion in typical circuits is somewhere in the range of millimeters per second.
gracy said:
why after crossing resistance only it's potential energy decreases,why not kinetic energy decreases
It can be different, that depends on the details of the cables. It does not matter as it is negligible.
 
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mfb said:
Depends on what you mean. "Electric potential" - yes. "Potential for the electron" - no.
i didn't understand this point.
 
All you have to do is use "s" after electron, they are plural, electrons. You can't single one out and look at it, they are a collective of potential.
 
jerromyjon said:
All you have to do is use "s" after electron, they are plural, electrons. You can't single one out and look at it, they are a collective of potential.
oh,you mean i should say electrons move from lower potential to higher potential but yet their potential energy decreases.Right?
 
gracy said:
oh,you mean i should say electrons move from lower potential to higher potential but yet their potential energy decreases.Right?
The potential is attribute of the electric field. The potential energy of the electron is PE=-eU at a place with potential is U. Moving to t higher potential, the potential energy of the electron gets lower.
 
ehild said:
The potential is attribute of the electric field. The potential energy of the electron is PE=-eU at a place with potential is U. Moving to t higher potential, the potential energy of the electron gets lower.
Thanks.Now it's clear.
 

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