Syllabus for Electrodynamics Seminar

Phys 112

Fall 1999

Version 3.0


"I have also a paper afloat, with a electromagnetic theory of light which, till I am convinced of the contrary, I hold to be great guns."

James Clerk Maxwell (1864)


The form of electrodynamics created by Maxwell in the 19th century is one of the most profoundly influential formulations in physics. It was a turning point in the history of science. For the first time, theoretical work unified two distinct disciplines, electricity and magnetism. It led to an understanding of light, gave us both new eyes and new ways of communicating in the form of new technologies. The theory’s form and success were largely responsible for many of the main movements in 20th century physics, including the search for (elusive) unified theories. So Maxwell was right, the theory is great guns. In fact, there are few subjects we could choose to study which are as theoretically satisfying and full of practical application.

It is also a vast subject.

Fortunately we have a master to guide us through the material. Griffiths writes a clear and interesting text. He uses a classical presentation: Mathematical background is presented first, followed by kinematics, dynamics, and applications. We will begin with the Maxwell’s mathematics in modern form.

A note on the course information: All materials will be posted on the web server as well as being printed for seminars. The advantage is that the documents can "live." As the semester progresses this syllabus and well as other documents will be modified. All versions will appear on the internet and will be labeled by a version number as in the top right of this page. The information is at

This syllabus is at


My Platonic Ideal of The Swarthmore Seminar: The professor provides a detailed syllabus of a subject which, if followed carefully, will build a solid foundation of the subject. The students, working together with the professor, learn and present the material in class in a way in which is clear to their classmates. Discussion is active, opened ended, intellectually challenging, non-threatening, and "pushes the envelope" of everyone’s understanding. In preparation every member has no problem asking others about a solution, an integral, or definition. In seminar any remaining issues are cleared up, effectively, briefly and, naturally, with a blinding flash of light. Finally, the goals are two: This work not only builds a solid understanding but also a personal text which can be referred to years and even months later.

The typical seminar will consist of a series of solutions and presentations punctuated by discussion. We will all contribute but I emphasize the complete reversal of roles. You take an active role in teaching yourselves. It is your class! (The last two sentences are in second person plural.)

Here are a few suggestions to help you along:

  1. Nothing will help you better than starting preparing for seminar early. As good as they are, these chapters are not short stories; it would be unpleasant to read the entire chapter in one sitting. Further, read with a scratch pad and writing utensil; work through the presentation of the text. Slogan: "Start early. Work slowly and carefully." This requires self-scheduling!
  2. Physics is not learned by reading. To learn the subject one must work through many problems. For many of us this process has two purposes. One is to gain mathematical fluency. The other is to understand the physics in the mathematics. Not always easy! As you solve problems, be clear about which sort they are and direct your thinking accordingly.
  3. One of the aspects of the seminar experience that took me the longest to learn was the utility of asking a question. If you encounter difficulty, carefully formulate a question (often the question "answers itself" in this process!), then ask someone. If this person is madly preparing a midterm or a bernaise sauce or does not know the answer, try someone else who is not preparing a bernaise sauce. In particular do not hesitate to ask me (DuPont 127, 690-6887, smajor1). If all else fails, go on to other problems and return to the question later. The slogan is: "Minimize frustration, maximize play!" Recently I was in a truck rental place. On the wall was a paper with a large circle on it. In the middle were printed the words, "Bang Head Here." This is a bad idea. Metaphorically or not, there is very little gain in working on a problem to the point of head-banging frustration.
  4. When writing solutions keep in mind that there is also a large difference in sketching a solution on your napkin at dinner and writing up the solution so that someone can read it (that may include you!) As with much writing, keep your audience in mind. Keep your classmates in mind but also try thinking of yourself in a 3 months. Much of what works for solutions is also true for presentations. Clearly state the issue or problem, outline the tools needed, and proceed providing information when needed.
  5. The best policy is to prepare fully for seminar before we meet then write up summaries and/or complete solutions after the actual seminar. This is not easy to keep up with but will be loads of help for the Honors exams, graduate school classes, qualifiying exams… Think of this as writing up a book from which you can relearn the subject.
  6. It is never too early (or too late) to start "being clear" about what you understand and what you don’t. There is a vast, amorphous plane between familiarity and understanding. Question your own understanding by trying it out on new situations. If your knowledge is not what is required, find the difference and learn from it.
  7. If you haven’t already started, start keeping a sheet of paper with useful formulae. There are a lot of these for electrodynamics.

For better or worse, grades are now part of the seminar experience. There are three aspects to the seminar which are key, a solid understanding of the subject, clear presentations, and a personal text. Therefore there are three parts to the grade:

  1. A midterm (the date of the midterm will be set in the first week) and a final, four hour take home exams, check your understanding. The midterm will be in the week after October holidays. It is a self-scheduled 4 hour exam during the "window" 8:00 Oct 19 to 18:00 Oct 20. (I’ll be out of the office for some of the time so I’ll leave the exams outside my office with a sign-in sheet.) Both exams will, by popular demand, be open book and notes. However, they will not be "open library" or discussion exams. I also encourage you to use a formula sheet and carefully review the material before the exam.
  2. Twice during the semester, once before the midterm and once after, we will all grade and offer short comments on a presentation of your choice (from a set of suggested presentations). Most of you have done one cycle. Keep this in mind so you don’t get caught without a choice.
  3. Finally, there will be one graded set of problems. This set will be novel in that you will be able to receive an A or no credit. In the second week (the day after seminar) you will hand in a set of problems for comments. If your solutions are clear then you have the A. If there are confusing aspects (or incorrect solutions) then I will return the set to you the following week with comments. You will then have the option of turning the solutions in again for the A (assuming the corrections have been made). When this is done you will have a concrete example of the way solutions ought to be written up for your personal text.

In sum the grade consists of three parts, your work in seminar (including presentations and the "model" problem set) (50%), the midterm (25%), and the final (25%).


Summary by Week


Thurs 9/2

Mon 9/

Or, at lower quality but in pdf (view with Acrobat Reader)


Thurs 9/9 Mon 9/13


Griffiths Chapter 2

Problems of note:

1,2,6,10,11,13,15,20,21,25,31, 32,34,35,37,49,50, plus "a problem of your own"

I think the quality of the pdfs is fine — especially when printed


Thurs 9/16

Mon 9/20

8:30 !

Techniques for finding fields and potentials

Griffiths Chapter 3

Problems of note:



Thurs 9/23

Mon 9 27

More on special techniques

Griffiths Chapter 3

Problems of note:


The seminar guide is included in last weeks "third"


Thurs 9/30

Mon 10/4

Electrostatics and matter

Griffiths Chapter 4

Problems of note:



Thurs 10/7

Mon 10/18


Griffiths Chapter 5

Problems of note:

3plus, 6,9,11,13,16,19,25,31,36,39


A four hour take home exam to be taken Oct 19 or Oct 20, see above

The exam includes material from chapters 1-5


Thurs 10/21

Mon 10/25

Magentostatics and matter

Griffiths Chapter 6




Thurs 10/28

Mon 11/1

The heart: Electrodynamics

Griffiths Chapter 7

Problems:2,6,7,11,16,20,33,49, 60



Thurs 11/4

Mon 11/8

Conservation laws

Griffiths Chapter 8




Thurs 11/11

Mon 11/15

Electromagnetic waves

Griffiths Chapter 9




Thurs 11/18

Mon 11/22

Potentials and fields: Fancy potentials and their ontological status

Griffiths Chapter 10

Plus additional article: G. Belot "Understanding Electromagnetism"

Brit. J. Phil. Sci. 49 (1998) 531

Problems:1,3,5,8,9,12,13,14,15, 25



Thurs 12/2

Mon 11/29


Griffiths Chapter 11

Problems: Prob 1, 3,10,11,14,22,23



Thurs 12/9

Mon 12/6

Electrodynamics and relativity: I

Griffiths Chapter 12




This four hour take-home will be self-scheduled during exam week

The material will include all of Griffiths .


Tues 12/14

Mon 12/13

Relativity II and Review

Griffiths Chapter 12

Problems:12.44,12.50,12.54, EM action, 2.15, 3.14, 51, 5.46, 7.43, 8.15


N.B. We will cover the first two Chapters in the first two weeks. Since the Thursday seminar is on the first day of classes, some of Chapter 1 may spill over into the second week. Let’s try to minimize this!