Faraday's Law vs Kirchoff's Rule in circuit - nonconservative fields

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SUMMARY

This discussion focuses on the comparison between Kirchoff's Loop Rule and Faraday's Law in the context of nonconservative electric fields. The user references specific resources, including MIT's OpenCourseWare and a YouTube video by Lewin, to illustrate the differences in how electric fields are treated in these two frameworks. The main confusion arises from the application of the integral form of Faraday's Law, particularly regarding the sign conventions used when calculating potential differences across resistors. The user seeks clarification on the apparent discrepancies in the application of these laws in non-closed paths.

PREREQUISITES
  • Understanding of Kirchoff's Loop Rule
  • Familiarity with Faraday's Law of Electromagnetic Induction
  • Knowledge of electric fields and potential differences
  • Basic principles of circuit analysis, including Ohm's Law
NEXT STEPS
  • Review the MIT OpenCourseWare materials on Kirchoff's Rule
  • Watch the referenced YouTube video by Lewin on electric fields and circuits
  • Study the integral form of Faraday's Law in detail
  • Explore discussions on nonconservative fields in physics forums
USEFUL FOR

Students and educators in physics, electrical engineers, and anyone interested in the principles of circuit analysis and electromagnetic theory.

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I am trying to compare the "relation" conventions used in Kirchoff's Loop Rule with Faraday's Loop Rule.

Kirchoff

Please go to this MIT OCW link on Kirchoff's Rule and go to page 8/29. Of the four boxes, I would like to point this one

K_E.jpg


Note that the yellow electric field was added by me. This picture also follows the integral

-\int_{a}^{b} \mathbf{E}\cdot d\mathbf{s} = \int_{a}^{b} -Eds = \Delta V = \varepsilon = -IR

Since ds and E are parallel.

Nonconservative Fields with Faraday

Now if I go to this video (I take you to EXACTLY where I want you to watch, so don't worry about searching which part of the video does this happen)

http://www.youtube.com/watch?v=UpO6t00bPb8#t=10m22s

Now quoting him

Now I go through the resistor, so I get +IR, since E and dl are in the same direction, Ohm's Law tells me I get +IR

Note that his circuit arrangement is exactly like mine, he went from a high potential to a low potential. The current, electric field in the wire, and the traveling direction are all the same, yet he gets +IR instead of -IR

is he still using this "E dot dl" -\int_{a}^{b} \mathbf{E}\cdot d\mathbf{s}= \Delta V? How does Faraday's Law apply for non-closed paths? Because it seems like Lewin is using \int_{a}^{b} \mathbf{E}\cdot d\mathbf{s}= \Delta V (no minus sign)

The same confusion goes when he talks about the electric field in the battery.

Could someone please clarify for me? Thank you
 
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Studiot said:
This subject has already been done to death here at this forum

eg

https://www.physicsforums.com/showthread.php?t=453575

do a forum search for other threads

and also here

http://forum.allaboutcircuits.com/showthread.php?t=16150&highlight=lewin&page=3

Second link wasn't very helpful and I can't pinpoint my answer in the first link because it seems like it derailed into some argument on Lewin's teaching ability.
 

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