PHY 415: Electromagnetic Theory I
Prof. S. Teitel: stte@pas.rochester.edu ---- Fall 2021
Unit 1 • Unit 2 • Unit 3 • Unit 4 • Unit 5 • Unit 6 • Unit 7 • Unit 8
Electromagnetic Energy and Momentum
October 14 to 22
You should review the notes and videos below by October 22.
Questions on the material of Unit 4 may be posted on the Unit 4 Discussion Board, or on the Unit 4 Slack channel.
Your response to Discussion Question 7 is due Tuesday, October 19, at 5pm
Your solutions to Problem Set 7 are due Thursay, October 21, at 5pm
In this unit we extend the ideas of energy and momentum to electromagnetic fields, defining the energy and momentum densities, and the energy and momentum currents. We show how these enter conservation laws for the total energy and momentum of a system of interacting charges. We also discuss the capacitance of a system of conducting bodies, and the inductance of a system of current carrying loops. We discuss the electromagnetic and magnetostatic energies stored in these configurations. We review the properties of electromagnetic waves in a vacuum, and discuss the energy and momentum carried by such waves. In supplemental notes, we discuss the force, torque, and interaction energy of electric and magnetic dipoles.
Below is a list of links to the course notes for each topic in this unit, followed by links to recorded video lectures.
Notes and Video Lectures
Video 4-1.2 - Energy conservation and the macroscopic Maxwell equations [20 min]
Video 4-1.3 - Electrostatic and magnetostatic energy [22 min]
Video 4-2.2 - Meaning of the Maxell stress tensor and the force on a conductor's surface [22 min]