Physics 331: Electricity and Magnetism
James Cook's Physics 331: Electricity and Magnetism
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Lecture Plan and Notes:
I should post my handwritten Lecture Notes from Physics 331 of Fall 2025 here. Probably they're just ripped out of Griffiths, except when they're not.
- Lecture 1: Vectors and Calculus: index notation for calculus and vectors.
- Lecture 2: Coordinate Frames: from geometry and calculus.
- Lecture 3: Dirac Delta Device: special nature of Coulomb field, introduction of Dirac Delta in one and three dimensions.
- Lecture 4: Static Electric Field: Coulomb field, field lines and derivation of Gauss Law.
- Lecture 5: Gauss Law and Dirac Deltas: Gauss Law and basic spherical, cylindrical and planar examples, also we study how the Dirac Delta function plays into these examples.
- Lecture 6 7: From Electric Fields to Potentials: interconnection of E-field, potential and charge density. Calculational techniques, conservative vector field properties of E, boundary conditions for field and potential. Formulation of potential either from integration of density or from integration of known E-field, conductors. (this concludes Chapter 2 of Griffiths)
- Lecture 8: Uniqueness Theorem for Laplace's Equation I included the explicit application to the method of images. I merely include the most important example of the method of images and how it allows us to derive the induced charge on the conducting plane due to a single point charge above the plane.
- Lecture 9: Laplace's Equation in Spherical or Cartesian Coordinates (separation of variables and Fourier techniques)
- Lecture 10: Laplace Equation in Spherical or Cylindrical coordinates (ok, we didn't get very far into the cylindrical case)
- Lecture 11: Legendre Polynomial Solutions of Laplace's Equation
- Lecture 12: Multipole Expansion potentials and fields can be seen as superposition of poles at origin
- Lecture 13: Electrostatics in Matter concept of polarization, dipole moment, bound charge in insulators
- Lecture 14: Electric Displacement and Linear Dielectrics construction of D, susceptibility and permitivity in linear dielectrics, boundary values, nontrivial curl of polarization of bar electret
- Lecture 15: Crystals, Capacitors and Energy summary thoughts about end of Chapter 4 in on Electrostatics in matter.
- Lecture 16: Magnetic Fields: derivation of Ampere's Law from the Biot-Savart Law mathematical primer on Biot-Savart and how we derive Ampere's Law.
- Lecture 17: Magnetic Fields: discussion of current distributions, conservation of charge and the continuity equation, examples of common magnetic fields both from Biot-Savart and Ampere's Law probably this material belongs before Lecture 16, much of this is really material from Physics 132.
- Lecture 18: The Vector Potential: definition and non-uniqueness, we discuss why scalar magnetic potential cannot be globally defined
- Lecture 19: Magnetic Monopole and the Aharonov-Bohm effect: we derive the vector potential for the magnetic monopole and note the Dirac-String type divergence which must appear, physicality of vector potential shown via Aharonov-Bohm example.
- Lecture 20: Boundary Conditions and Magnetostatics in Matter: we study magnetic field and vector potential at boundary surface, spinning charged spherical shell example worked in detail, magnetization introduced and uniformly magnetized sphere seen to connect to spinning charged sphere.
- Lecture 21: Magnetostatics in Matter: uniformly magnetized sphere revisited, bound currents derived, auxillary field H discussed and applied. Diagmagnetism, Paramagnetism and Ferromagnetism contrasted (not much said on Ferromagnetism, my apologies)
- Lecture 22: EMF and Faraday's Law: discussion of motional EMF and other EMFs given, then connection to Faraday's Law through Griffith's "Universal Flux Rule". Maxwell's Law known as Faraday's Law introduced. Novel calculation of induced electric field via magneto static analogy shown. Quasistatic approximation introduced and cautionary example given.
Missions for Physics 331:
- Mission 1: Vectors, Calculus and the Dirac Delta
- Mission 2: Electrostatics, finding electric fields and potentials.
- Mission 3: Electrostatics, method of images, solutions of Laplace equation.
- Mission 4: Electrostatics in matter.
- Mission 5: Magnetostatics.
- Mission 6: Magnetostatics in Matter and Electrodynamics.
- Mission 7: Conservation Laws and Electromagnetic Waves
- Mission 8: Radiation.
Solved Problems from 3rd ed. of Griffiths:
These solutions are mine from my undergraduate work at NCSU in the previous millennium.
Notes from my time at NCSU:
These are probably not helpful, I post them here for my amusement. These are based on the 3rd edition of Griffith's Introduction to Electrodynamics
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Last Modified: 10-14-2025