Looking for a textbook that uses the electromagnetic wave view of electric current

  • #1
DrBanana
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So I watched a couple of videos on Youtube with the titles 'How Electricity Actually Works' and 'The Big Misconception About Electricity' ( and ).

The main message being that while the view of current being the flow of electrons might be useful practically, it's not an accurate representation of what actually happens, and the more accurate description is that the energy is propagated as electromagnetic waves.

I appreciate the clarification but it also brings up a lot of questions, because much of what you learn about related stuff is based on the fact that electrons flow in a significant amount through wires, such as wires heating up, or even the Peltier Effect. So I was looking for a textbook that started with this more accurate view, and gradually built on that.
 
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  • #2
DrBanana said:
The main message being that while the view of current being the flow of electrons might be useful practically, it's not an accurate representation of what actually happens, and the more accurate description is that the energy is propagated as electromagnetic waves.

I appreciate the clarification but it also brings up a lot of questions, because much of what you learn about related stuff is based on the fact that electrons flow in a significant amount through wires, such as wires heating up, or even the Peltier Effect. So I was looking for a textbook that started with this more accurate view, and gradually built on that.
While I don't have any textbook suggestions, this is a topic that has been discussed previously here on Physics Forums. For example, here is a thread that I participated in:
https://www.physicsforums.com/threads/power-flow-outside-a-wire-how-close.1053463/
Note that, while it's true that "electrons flow in a significant amount through wires", they travel so slowly that they carry very little total energy. Instead, the flow of electrons through the conducting circuit serves to create and direct the electric and magnetic fields outside of the wires, and it is those fields that transport the bulk of the energy. And this transport is not by "electromagnetic waves" in the usual sense of transversally-polarized radiation (e.g., radio waves or microwaves), since those would escape from the circuit and carry energy away to infinity. Instead, at DC or low frequencies like 50-60Hz, the energy is propagated by EM "near-fields", i.e., fields confined to the vicinity of the circuit.
 
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  • #3
I think you are asking about how transmission lines work (or "open waveguides"), there should be lots of textbooks on this subject.

Maybe try a google search?
This is some of what I found without too much effort, then I got bored and gave up. I'm not THAT interested in reliving my EM courses from several decades ago.

https://www.feynmanlectures.caltech.edu/II_24.html
http://www.corridor.biz/FullArticle.pdf
 
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  • #4
Any textbook on electrodynamics should do (except some didactics textbooks, which still promote the "water-pipe analogy" for circuits, which is completely misleading for the very reasons you discovered on Youtube, though I haven't seen these videos, so I can't judge, how reliable they are).

A very thorough discussion of the most simple exactly solvable case, the "infinitely long" cylindrical coaxial cable for a DC circuit, is in A. Sommerfeld, Lectures on Theoretical physics vol. 3. That's doable at the undergrad level.

For the more interesting case of time-dependent fields, e.g., to answer the question of signal propagation when switching on the circuit or for AC circuits, you need a bit more advanced methods. If you restrict yourself to the most simple "TEM mode" of the coax cable you get the "telegrapher's equation", which is also doable at the advanced undergrad level. The full-fledged wave-guide theory is a bit more advanced. It can also be found in Sommerfeld's books (also in vol. 6 about partial differential equations, which is anyway highly recommended).
 
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FAQ: Looking for a textbook that uses the electromagnetic wave view of electric current

What is the electromagnetic wave view of electric current?

The electromagnetic wave view of electric current considers the flow of electric current as being accompanied by electromagnetic waves, rather than just the movement of electrons through a conductor. This perspective emphasizes the role of the electric and magnetic fields in transmitting energy and information along the current path.

Why is the electromagnetic wave view of electric current important?

This view is important because it provides a more comprehensive understanding of how electric currents interact with their surroundings. It helps explain phenomena such as signal propagation in transmission lines, the behavior of antennas, and the skin effect in conductors at high frequencies. This perspective is crucial for fields like telecommunications, radio-frequency engineering, and advanced circuit design.

Can you recommend a textbook that uses the electromagnetic wave view of electric current?

One highly recommended textbook is "Fields and Waves in Communication Electronics" by Simon Ramo, John R. Whinnery, and Theodore Van Duzer. This book provides a thorough treatment of the subject, integrating the electromagnetic wave perspective with practical applications in communication systems and electronic devices.

How does the electromagnetic wave view differ from the traditional view of electric current?

The traditional view of electric current focuses on the movement of charge carriers, like electrons, through a conductor. In contrast, the electromagnetic wave view emphasizes the role of electric and magnetic fields in the propagation of current. This view considers the energy transfer through these fields, providing a more holistic understanding of current behavior, especially at high frequencies.

What prerequisites are needed to understand the electromagnetic wave view of electric current?

To understand the electromagnetic wave view of electric current, a solid foundation in electromagnetism is essential. This typically includes knowledge of Maxwell's equations, electric and magnetic field theory, and wave propagation. Courses in advanced physics, electrical engineering, or communications engineering would provide the necessary background to grasp the concepts presented in textbooks on this topic.

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