Electricity and Magnetism

"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."

Welcome to Physics 351! In this class we will study charges, currents, electric and magnetic fields, and their interactions. Much of the physics is expressed in a single, remarkable set of equations

\begin{gather} \vec{\nabla} \cdot \vec{\mathbf{E}} = \frac{1}{\epsilon_{0}} \rho \vphantom{\frac{\partial\vec{\mathbf{B}}}{\partial t}} \\ \vec{\nabla} \times \vec{\mathbf{E}}\,= - \frac{\partial\,\vec{\mathbf{B}}}{\partial \,t} \\ \vec{\nabla} \cdot \vec{\mathbf{B}} = 0 \vphantom{\frac{\partial\vec{\mathbf{B}}}{\partial t}}\\ \vec{\nabla} \times \vec{\mathbf{B}} = \mu_{0}\,\vec{\mathbf{J}} + \mu_{0}\,\epsilon_{0}\,\frac{\partial\,\vec{\mathbf{E}}}{\partial\,t} \end{gather}

This formulation of electromagnetism is due primarily to the Scottish physicist James Clerk Maxwell. His equations, in one form or another, describe phenomenon ranging from the propagation of light to the deflection of a compass needle by a magnetic field.

James Clerk Maxwell (1831-1879)

The impact of Maxwell's equations extends well beyond electromagnetism: the Theory of Special Relativity is secreted away inside them, and they are the prototype for a unified description of the basic forces of Nature.

Syllabus

Basic information about our schedule, homework assignments, grades, and more can be found below. Click here to download a pdf version of the full syllabus. The syllabus has more detailed information, and you should be familiar with the policies and rules it describes.

Spring 2015 Schedule

We will cover most of the first nine chapters of the textbook, with the exception of parts of chapters 8 and 9. The table below is an estimate of how we'll spend our time.

Week Dates Chapter
1 January 13, 15 1
2 January 20, 22 1, 2
3 January 27, 29 2
4 February 3, 5 2
5 February 10, 12 2, 3
6 February 17, 19 3
7 February 24, 26 3
8 March 3, 5 Spring Break
9 March 10, 12 4
10 March 17, 19 5
11 March 24, 26 5
12 March 31, April 2 5
13 April 7, 9 6
14 April 14, 16 7
15 April 21, 23 9

Please keep in mind that these dates are subject to change -- I may decide to switch things around or spend more or less time on a given chapter. I will always notify you about any changes I make to this schedule.

Assignments

Homework is assigned each week and collected the following week. Three or four problems from each assignment will be graded. I won't tell you which ones, so you need to complete all the problems. Current and past assignments are listed below. Solutions are available for some (not all) problems, but I am no longer making them available for download — please stop by my office if you'd like to see the solutions for a particular assignment.

Assignment 1
Review of Vector Analysis
Due on January 13

This assignment is due at the beginning of the first class. It is a review to get you up-to-speed on some aspects of vector analysis that we will frequently use in class.

Working with your classmates on these assignments is encouraged! But you should only hand in work that you've completed on your own. If your solution looks just like someone else's work then you need to go back and redo it from scratch. If you can't explain each step of your solution then you haven't completed the problem on your own. Remember: the only way to be ready for the exams is to do the homework yourself.

A Warning

Never, ever hand in an assignment that has been copied from a solutions manual. You won't learn anything that way, and it will earn you a grade of zero for that assignment. If it happens more than once it will be reported to the Department Chair and the Dean. Consider yourself warned. Click here to see the College of Arts and Sciences Statement on Academic Integrity.

Grades

Grades in the course are primarily determined by homework assignments and exams. The weekly homework grades contribute 35% of your final grade in the class, and two “midterm” exams (dates TBA) count 15% each. A cumulative final on May 1 (from 9:00-11:00 AM) is worth 30%. The remaining 5% depends on attendance and participation. Asking questions, taking advantage of office hours, and attending both lectures and discussion sections will earn you the full 5% — see the pdf syllabus for more details.

References

The main text for the class is Introduction to Electrodynamics by Griffiths. The tone of the book is casual and most students find it very accessible. When I was an undergraduate I used the the books by Wangsness and Purcell. Those texts might be useful if something in Griffiths isn't clear. A more advanced treatment is given in Jackson's Classical Electrodynamics, which is the text for practically every graduate E&M course.

  1. Introduction to Electrodynamics
    David J. Griffiths
  2. Electromagnetic Fields
    Roald K. Wangsness
  3. Electricity and Magnetism
    Edward M. Purcell
  4. Classical Electrodynamics
    J.D. Jackson

Griffiths' book has a very complete (for our purposes) discussion of vector calculus as it is used to describe electricity and magnetism. If you'd like to see additional discussions of this material, I recommend the math methods book by Boas, and also the book by Riley, Hobson, and Bence. For a more advanced treatment refer to Arfken and Weber.

  1. Mathematical Methods in the Physical Sciences
    Mary L. Boas
  2. Mathematical Methods for Physics and Engineering
    K.F. Riley, M.P. Hobson, and S.J. Bence
  3. Mathematical Methods for Physicists
    George Arfken and Hans Weber

From time to time I may supplement the material from the book with my own notes, which will be posted below.

Notes

Line Integrals

This is a very basic review of line integrals -- what they are, how to evaluate them, etc. It may be useful if you're a little rusty on this topic. The file is big (about 22 MB) because of the various plots. Let me know if you find any typos or mistakes and I will post a corrected version.

E&M Stress Relief

Sometimes the E&M wears you out, and you need a picture of an adorable little kid doing physics to get you back on track. Not a problem.