PHYSICS 405

Intended Syllabus/Schedule for the Class

Spring 2006 Daniel Finley
MWF 10:00 - 10:50 AM , PandA 184
Note:    Problem Session, Physics 451-056, meets Wednesday at 3:30 pm, in Room 5 [1 credit hour; CR/NC grade]

Texts:     Introduction to Electrodynamics, David J. Griffiths; 3rd Edition
    div, grad, curl and all that,    h. m. schey;      a supplemental book for the essential vector calculus of the title.
 
  We should cover the first 7 chapters of Griffiths; a more detailed description of the material is given below.
 Other Books: Go to this link for other suggested readings, especially those on reserve.
 Prerequisites:
  • Junior status or higher: i.e., have finished the standard, 3-semester introductory course on physics, and calculus,
    Phys. 160, 161, 262, and Math. 162, 163, and 264.
  • Intermediate Mechanics I, Phys. 303.
  • Vector Analysis, Math. 311 and Ordinary Differential Equations, Math. 316.

The text has been used in this department for several years, and has been well-liked.
This page gives a brief outline of the chapters, indicating how much time I will use to cover them in the lectures in the class, and then links from each chapter to some notes that I have made, for that chapter.
  From time to time, additions/changes will be posted in the material already presented. To make it easier to locate them, they will be written in a bold green font like this.
Please use the overall schedule as a guide to your "first, or second, readings" of the material, and then use my notes here and your own in-class notes for your more in-depth study of the material, and your working through the problems. Do try very hard to work through more of the problems than simply those that I choose to assign. I will be happy to help you with these "other" problems if you wish.
  I also feel that this is a time in your studies when it is very important to begin reading material from more than one source, to create your very own synthesis of the material that is appropriate for yourself.
    Therefore, I have included another website where some other books are listed. Some of them are on reserve, for loan, in the department office, and there will be reading assignments made there from time to time.

    Schedule for the Chapters
  1. Ch. 1: Vector Analysis and Curvilinear Coordinates: 18-30 January (first 2 weeks).
    Since this material can be somewhat dry, we will regularly pull examples from the (introductory) material of the next chapter.
    As well, since the presentation in your text is somewhat brief, we have the supplementary book, div, grad, curl, and all that, which is very detailed and reviews well much of the material that you were supposed to have learned in Math. 311.
  2. Ch. 2: Electrostatics: 1-13 February (2 weeks).
    Large portions, but definitely not all, of this chapter is review of material that I am sure you learned in introductory physics, as a freshman: applications of Gauss' Law, or equivalently, Coulomb's Law, to various sorts of problems where nothing depends on time. Nonetheless, reviewing it has value, and working the problems has even much more value, since it will provide the basis from which we begin to approach the new material in much of the rest of the text. We also use the time-independent version of Faraday's Law to create a potential function for the electric field.
  3. The First Exam will be on Wednesday, 15 February, during the regular time of the problem session, and will cover Chapters 1 and 2.
  4. Ch. 3:  Special (Mathematical) Techniques for Electrostatics: 15 February - 3 March (2 1/2 weeks).
    We learn new mathematical techniques to determine the requirements of Coulomb's Law in more complicated situations. Using the electrostatic potential, these amount to methods to solve Poisson's equation (or Laplace's equation) under various sorts of boundary conditions. We also study these equations in cylindrical and, especially, spherical coordinates, where Legendre polynomials become quite important, allowing us to define multipole moments of complicated charge distributions.
  5. Spring Break occurs for the entire week of 12-18 March.
  6. Ch. 4:  Electrical Fields in Matter: 6 March - 27 March (2 1/3 weeks).
    Inside materials we devise a separation of the electric fields into those dependent on "free charges" and those caused by the polarization of the "bound charges" that must stay close to where they originate, inside that material.
  7. The Second Exam will be on Wednesday, 29 March, as usual during the time for the problem session, and will cover Chapters 3 and 4.
  8. Ch. 5: Magnetostatics: 31 March - 12 April (2 weeks).
    Here we will concentrate on the similarities, and the important differences, between the magnetic problems and the electric problems. The additional physics comes from Ampere's Law, or, equivalently, the Biot-Savart Law, relating magnetic fields to currents. Many of the mathematical techniques are very similar to the electric ones. However, the zero divergence character of the magnetic field creates for it a potential, but one which is a vector field, therefore making problems more complicated than those for the electric field, where the potential was just a scalar function.
  9. Ch. 6: Magnetic Fields in Matter: 14-21 April (1 1/3 weeks).
    Under the influence of magnetic fields, inside materials we have a separation into "free currents" and "bound currents", which allows us to devise now a separation of the magnetic fields into those dependent on the two sorts of currents. This also introduces diamagnetic, paramagnetic, and ferromagnetic materials.
  10. The Third Exam will be on Wednesday, 26 April, during the problem session time, and will cover Chapters 5 and 6.
  11. Ch. 7: Beginning Electrodynamics: 24 April - 3 May (1 1/2 weeks).
    Here we leave the domain of time-independent phenomena, and recall the very important changes that time dependence can play, in both Faraday's Law and the time-dependent addition that Maxwell made to Ampere's Law, justifying giving it a new name. Lastly, we look at these as a unit, constituting the set known as Maxwell's equations, all preparatory to a serious study of the time-dependent properties in the next semester.
    Much of this material is review from freshman physics, again. However, it was rather "tricky" then, so we need to see if we cannot understand it a little bit better this time through!
  12. The last lecture class will be on 5 May, and will be an important Review Session for the semester.
  13. The Final Exam will be on Monday, 8 May, at 10:00 am, for 2 hours. It will be comprehensive over the entire semester, with about 1/3 of the material concentrating on those subjects since the Third Exam.

Some Additional, General Notes On Your Text
The author of your text is very concerned that you, his readers, should acquire a well-developed intuition concerning how electromagnetic phenomena work. This is quite understandable, since both students and faculty tend to consider electromagnetism to be rather more mathematical than those subjects that students have encountered previously in physics.
There are several plausible reasons for this, which would include the following:

For these reasons, and perhaps others, the author is trying to convince you to concentrate on the essence of the physics, rather than the "picky" details of the vectorial mathematics. This is a good plan and we need to work together to see that your intuition is actually developed, along the lines he describes. This is something like saying that we want to bring you to the point where, after having done some long calculation, you can quickly say whether or not it "looks right."
Such intuition is an incredibly important thing to develop.
However, in the process of doing this, the author sometimes makes "belittling" statements about mathematical rigor that are too "sloppy." We need to watch his statements about this and that mathematics, and at least occasionally know a bit more than he suggests we need to.

Some other, more specific comments:

  1. He uses SI units, namely [m,kg,s,C], with only some reference in an appendix to the existence, and relationship, of Gaussian and Heaviside-Lorentz units. This approach is usual, although it can be difficult at times, either when one consults other books or goes further into a more advanced course, where Gaussian units are much more commonly used.
  2. Most of physics involves
    observations of phenomena at some (field) point, located by some vector, say , relative to some choice of origin,
    caused by occurrences at some (source) point, denoted by some other vector, say , relative to the same origin.
    Therefore it is very common to be interested in the difference of these two locations. Use of a single symbol for this difference simplifies the appearance of the formulae, and also sometimes obscures the intent of the formula. Therefore most authors of texts use some special symbol for
    the vector from the source point to the field point,. Griffiths uses the symbol     for this difference, i.e., to mean - .
    I have difficulty duplicating his symbol on the blackboard in class and also in homework solutions; therefore, I will be using for the same purpose the Greek letter "xi", = - instead, although with an arrow over the top to remind us that it is indeed a vector.

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  Last updated/modified: 16 January, 2006