Understanding Potential Difference and EMF in Electric Circuits

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Discussion Overview

The discussion revolves around the concepts of potential difference and electromotive force (EMF) in electric circuits. Participants explore the definitions, differences, and implications of these terms, particularly in relation to energy transfer and measurement in circuits.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant suggests that potential difference involves negative work (energy loss for electrons), while EMF involves positive work (energy gain for electrons), questioning how these concepts relate.
  • Another participant expresses confusion about previous explanations and seeks further clarification on the topic.
  • A participant notes that terms like EMF, voltage, and electric potential seem to refer to similar energy concepts but emphasizes the need for energy renewal to maintain these states.
  • There is a question about whether EMF and potential difference are effectively the same in a circuit and if they produce the same effects.
  • One participant provides a definition of voltage as electric potential energy per unit charge and distinguishes it from electric potential energy, explaining that EMF is energy per unit charge provided by a generating mechanism.
  • A later post questions whether a measured potential after a resistance drop in a circuit should be classified as EMF or potential difference, seeking clarity on the terminology used in this context.

Areas of Agreement / Disagreement

Participants express varying interpretations of the relationship between potential difference and EMF, with no consensus reached on whether they are the same or how they should be classified in specific circuit scenarios.

Contextual Notes

Some participants may be operating under different definitions or understandings of potential difference and EMF, leading to ambiguity in their discussions. The relationship between these concepts and their implications in circuit measurements remains unresolved.

tonyjk
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hello... potential difference between two points in a circuit is the work done by the electric field to get a charge from point to another and for the emf it's also the work done but my question is for a potential difference the work is negative( the electrons lose energy) and for the emf the work done is positive( the electrons gain energy) ? or what? and the potential measured between a point of a circuit and the ground is it an emf or a potential difference( so it's like a given energy or a loss of energy)? thank you:D
 
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i have read some threads made here but i didnt 100% get the response through them so please if any of the admins or members can help me.. thanks again
 
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Emf, voltage, electric charge, potential (difference), seems to refer to the more or less the same form of energy. They fade doing work if the energy is not renewed.
 
so the emf and potential difference are the same in a circuit? they have the same effects?
 
Voltage is electric potential energy per unit charge, measured in joules per coulomb ( = volts). It is often referred to as "electric potential", which then must be distinguished from electric potential energy by noting that the "potential" is a "per-unit-charge" quantity.

The emf represents energy per unit charge (voltage) which has been made available by the generating mechanism and is not a "force".

This is a good explanation. For further reading see. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/volcon.html#c1
 
okay i understand but my question is in a circuit when we measure a potential at a point A to the mass is it a potential difference or an EMF( if we take an EMF=5V and a resistance and after the resistance the potential is dropped and we have a new potential for exemple equal to 4.25V after the resistance,this potential referred to the mass is it an emf or a potential difference?)
 

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