# Classical ElectroDynamics

Classical Electrodynamics is an upper-division course for Physics students. In a perfect world it would be a single year-long class, but for administrative reasons it is split into two separate classes taught by different professors:

• 352 K — Classical Electrodynamics (I) — a required class offered every long semester.
• 352 L — Classical Electrodynamics (II) — an optional class offered in Spring semesters only.
Physics-wise, the split is rather arbitrary, so if you want to be a physicist, you should take both of these classes!

This document is the syllabus of the Classical Electrodynamics (I) class as taught by Dr. Vadim Kaplunovsky in the Fall of 2018, unique number 56195.

## Textbook

The textbook for the 352 K class is Introduction to Electrodynamics by David J. Griffith, 4th edition. This textbook is required — I shall use the problems in the book as homeworks.

The 352 K class will focus on textbook chapters 1 through 7. The remaining chapters 8 through 12 will be covered in the 352 L class.

### Supplementary notes

Besides the Griffith's textbook, I shall not use any supplementary textbooks in my class. Instead, I shall sometimes write my own supplementary notes or use some material on the Internet. The links to all such supplementary notes will be posted to this web page.

## Course Content

### Classical Electrodynamics (I)

Math of vector fields:
Gradient, divergence, curl, and relations between them; second derivatives; line, surface, and volume integrals; fundamental theorems; delta-functions; differential equations for the fields.
Electrostatics:
The electric field and its divergence and curl; Gauss law and its uses; electrostatic potential and the Poisson and Laplace equations; boundary conditions; electrostatic energy; conductors and surface charges.
Solving the Laplace equation for the potential:
Boundary conditions; image charges; separation of variables method; multipole expansion.
Electric fields in matter:
Polarization of dielectrics; induced dipole moment; electric displacement field D; fields and energies in dielectric systems; forces on a dielectric.
Magnetostatics:
Magnetic field and its divergence and curl; magnetic forces; Biot–Savart–Laplace law; Ampere law; the vector potential.
Magnetic fields in matter:
Diamagnetic, paramagnetic, and ferromagnetic materials; induced magnetization; the H field and the Ampere law; linear and non-linear materials.
ElectroDynamics:
Ohm law and EMF; electromagnetic induction; Faraday's law; Maxwell's equations.

### Classical Electrodynamics (II)

Conservation Laws:
Continuity equation and conservation of the electric charge; Poynting vector and EM momentum; EM pressure and stress tensor; EM work and energy.
Electromagnetic Waves:
Waves and the wave equation; EM waves in vacuum; EM waves in matter; absorbtion and dispersion; guided EM waves.
Electromagnetic potentials:
Scalar and vector potentials; gauge transforms; potentials of continuous charges and currents; potentials of moving point charges.
Electrodynamics and special relativity:
Special relativity; relativistic mechanics; relativistic EM fields; Lorentz transforms of potentials and fields; 4–vectors and tensors.

## Prerequisites

The Classical Electrodynamics classes are intended for the upper-division Physics students who have already completed the lower-division Physics class sequence 301–316–315–319 (plus the corresponding labs) as well as Mathematics class sequence 408 C+D and 427 K+L (or any of the equivalent math classes). These are not just the formal prerequisites — you would really need that knowledge to follow the upper-division Physics classes.

The formal prerequisites — checked by the registrar computer — for the 352 K class are Math 427 L or 364 K and Physics 315 and 115, all with grades no worse than C−. Please note that I have no authority to waive these prerequisites!

If you have taken the prerequisite classes outside the UT, or if you have any other kind of prerequisite or registration problem, please go to the undergraduate coordinator at the Physics departement:

## Logistics

Instructor:
Assistant Instructor:
• Jeongheon Choe.
• Email: jeongheon@utexas.edu.
• Office: RLM 7.210.
• Hours: Tuesdays 1 to 2 PM and Fridays 1:30 to 2:30 PM.
Regular Lectures:
Tuesdays and Thursdays, from 3:30 to 5 PM, room RLM 7.104.
Lecture Log:
For students' convenience, I shall keep a log of lectures and their subjects on this web page. Since the pace of the course may change according to the students' understanding, I will not make a complete schedule at the beginning of the class. Instead, I will simply log every lecture after I give it. This way, if you miss a lecture, you will know what you should read in the textbook and other students' notes.
Extra Lecture (additional material for the interested students):
Hamiltonian in a magnetic field, Aharonov–Bohm effect, and Dirac monopoles, November 22 (Wednesday), 5:15 to 6:45 PM, in room RLM 5.116; repeated on Thursday 11/29 after the class in my office.
Review sessions:
• Review for the first mid-term test, Thursday 10/4, from 5:15 to 6:30 PM, room RLM 5.104.
• Review for the second mid-term test, Thursday 11/15, from 5:15 to 6:30 PM, room RLM 5.114.
• Review for the final exam, Wednesday 12/12, from 3 to 4:30, room RLM 5.114.

The grades for this class will be bases on the homeworks, 2 midterm exams, and the final exam.

• 20% of the average of 10 best homework sets (out of 12 sets total).
• 20% for each of the two midterm exams. (40% altogether).
• 40% for the final exam.

The brackets for converting the combined HW+MT+FIN scores into letter grades will be set after the final exam.

## Homework

Homework is essential for learning any difficult material. Often after listening to a lecture and/or reading the textbook you may feel like you know the material, but to make this knowledge useful you must learn how to actualy apply it to solving problems, and that's what the homework is for. Without doing the homework, you will never master any Physics or Math; at best, you might «have heard something about it».

To encorage you to do your homework for this class, it will comprise 20% of your grade. There will be 12 largish homework sets over the semester; 10 best sets will count towards your grade. To allow for illness or emergencies, you get to drop two worst (or missing) sets.

The homework assignments will be posted at this web page. Most of the problems will be taken from the Griffith's textbook, but sometimes I'll add a few problems of my own.

I shall collect the homeworks in class and give them to the TA to grade. If you cannot come to the class for any reason, please scan your homework (or take a clear picture with your digital camera or phone) and email it to me and to the TA before 5 PM on the day the homework is due. Please do not waste time asking my permission to submit your homework electronically, just scan it and email it.

Your homework should make clear what are you trying to do and why. Please comment your formulae (unless they are obvious). This way, if you make mistakes you would still get partial credit for trying to do the right thing.

Once the homeworks are collected I shall post the solutions and link them to the homework web page.

## Exams

This class has two midterm exams and one final exam at the end of the semester. Each midterm contributes 20% to your grade, and the final exam is worth 40% of the grade.

The midterm exams are taken in class — at the regular class time in the usual classroom.

• The first midterm is on October 9 (Tuesday). Subjects: textbook chapters 1, 2, and most of chapter 3.
• The second midterm is on November 20 (Tuesday). Subjects: end of textbook chapter 3, all of chapters 4 and 5, and the beginning of chapter 6.

The final exam is on December 18 (Tuesday), 9–12 AM, in room SZB 104. The final exam is comprehensive and covers the whole course, from the first lecture to the last, or in textbook terms, everything in chapters 1 through 7.

All the exams are open-books and open-notes. You may bring any paper books you like, but mind the limited space on your seat's armrest. The electronic books must be on a reader without an interactive web browser.

To prevent cheating, no communication devices are allowed during the exams. This means: no cellphones, no computers, no tablets, etc., etc. If you need to use a calculator or an e-book reader, make sure it's a separate device without a web browser or any other ways to communicate with other people.

Unlike the homeworks, you do not get to drop any midterm or final exams. If you miss an exam because of a documented illness or emergency, please let me know as soon as possible, and I'll work out an appropriate remedy. But if you miss an exam for any other reason, you would be SOL and your grade would suffer.

However, I shall allow students to take their exams ahead of the regular exam date in case of schedule conflicts. If you know ahead of time that the exam date and time conflicts with another exam, a pre-scheduled UT event you must participate in, a religious holiday you observe, a job interview, or with any other commitment, — please contact me two weeks ahead of time so I can reschedule your exam to a mutually convenient date and time.

Likewise, the students who need extra time to complete their exams due to a disability, please contact me two weeks before the exam to set up the time and the place for your test.