How Does Potential Difference Relate to Faraday's Law?

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SUMMARY

The discussion clarifies the relationship between potential difference and Faraday's Law, emphasizing that the potential difference is defined as the negative integral of the electric field (E) along a path. It highlights that the closed loop integral of E, as described by Faraday's Law, equates to the induced electromotive force (ε-induced), which is not treated as a potential difference. The distinction is made that while the voltage from an electromotive force is computed positively, the voltage from an electrostatic source is computed negatively, leading to the conclusion that induced electric fields do not correspond to a potential function.

PREREQUISITES
  • Understanding of Faraday's Law of Electromagnetic Induction
  • Familiarity with vector calculus, specifically line integrals
  • Knowledge of electric fields and potential difference concepts
  • Basic principles of electromotive force (EMF) in circuits
NEXT STEPS
  • Study the mathematical formulation of Faraday's Law in detail
  • Learn about the properties of induced electric fields and their implications
  • Explore the differences between electrostatic and induced electric fields
  • Investigate applications of Faraday's Law in inductors and transformers
USEFUL FOR

Students of physics, electrical engineers, and anyone interested in the principles of electromagnetism and their applications in electrical circuits.

Nikhil Rajagopalan
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The potential difference between two points is given ans the negative of integral of E(vector) <dot product> dl(vector) from initial to final points.
Therefore, integral integral of E(vector) <dot product> dl(vector) from initial to final point should give the negative of potential difference between them.
In Faraday's law, closed loop integral of E(vector) <dot product> dl(vector) is given as ε- induced. Why is it not the negative of ε-induced. Should ε-induced not be treated like potential difference?
 
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The voltage from an EMF with ## V=+\int E_{induced} \cdot ds ## gets computed in just the opposite way of how the voltage from an electrostatic source gets computed as ## V=-\int E_{electrostatic} \cdot ds ##. It should be noted, the induced ## E ## does not give rise to a potential and, in general, ## \nabla \times E_{induced} \neq 0 ##, so that we cannot write ## E_{induced}=-\nabla \Phi ##. The ## V ## from a Faraday EMF is a voltage, at least when it is observed in an inductor, but it is not a potential type function. ## \\ ## In a conductor, since ## E_{total}=0=E_{induced}+E_{electrostatic} ##, we have ## E_{electrostatic}=-E_{induced} ##. The argument can be made that this is why the voltage from an inductor is in fact ## V=\mathcal{E}=+\int E_{induced} \cdot ds ##.
 
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