PYSICS 30471Electricity & Magnetism

Tuesday and Thursday 12:30-1:45

At DeBartolo, Room 119

By Prof. S. Frauendorf

125 NSH 1-3875 sfrauend@nd.edu

Office hours: Tuesday and Thursday 10:30-11:30

Homework:Every week, due on Tuesdays by 16:00.Will be provided as MS doc file in the 30471 course space.Late homework policy: Turned in within the week of the deadline: 75%within the following week: 50%later: 0%Graded HW back after 2 weeks.

Midterm Exam 30%Final Exam 40%Homework 30%

Grade

Grades available on WebCT

Teaching assistant: Sun Jie(Jason) , room 120 tel.:1-4743 jsun@nd.edu

StyleCombination of Powerpoint slides containing the most important resultsavailable in the course space phys30471.01I:\coursefa.06\phys\phys30471.01and handwritten notes derivations, explanations, …

SyllabusText: Introduction to Electrodynamics, David J. Griffiths, (3rd ed. 1999 ), Chapters 1-7

1. Vector Analysis2. Electrostatics3. Special Techniques4. Electric Fields in Matter5. Magnetostatics6. Magnetic Fields in Matter7. Electrodynamics

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What is electrodynamics, and how does it fit into the general scheme of physics?

Natural phenomena are governed by the electromagnetic interaction.

It governs our man-made world as well.

It keeps the molecules together.

Even where you do not expect it, the electromagnetic interaction is at work.

Mechanics tells us the reaction of a body to a force.

Forces are given.

Electromagnetism is the theory two types of forces:Electric forceMagnetic force

Classical MechanicsNewton

Quantum Field TheoryDirac, Pauli, Feynman,Schwinger, ….

Quantum MechanicsBohr, Heisenberg,Schrödinger, …

small

Special RelativityEinstein

fast

Electric Charge (q, Q)

1. Charge exists as +q and –q. At the same point: +q-q=02. Charge is conserved (locally).3. Charge is quantized. +q =n (+e), -q = m (-e), m, n, integer

electron: –e, positron: +e, proton: +e, C-nucleus: 6(+e)Charge conservation in the micro world: p + e -> n (electron capture)

Macro world: q ~ 2310 e

Quantization is unimportant. Imagine charge as some kind of jelly.

The Field Formulation

q qF

E

q

v = cLight wave

Four kinds of forces - interactions

1. Strong Keeps nuclei and nucleons together. 2. Electromagnetic Most common phenomena.3. Weak β-decay n->p+e+ν4. Gravitational Keeps the Universe together.

Unification

electric + magnetic electromagnetic

electrodynamic + weak electroweak

electromagnetic + optic electrodynamic

In Quantum Field theory the difference between particlesand forces becomes ratherdiffuse.

Two types of quantum particles:Fermions and Bosons.

SI-UnitsSysteme Internationale

Mechanicslength: meter (m) mass: kilogram (kg)time: second (s)force: newton ( )2 smkgNwork: joule (J = N m)Power: watt (W = J/s)

Electromagnetismcurrent: ampere (A)charge: coulomb (C = As)voltage: volt (V )

work: (W s = V A s)power: watt (W = V A)

The equations of EM contain

As

Vm

C

Nm

cAm

Vs

Vm

As 92

29

02

0

70

120 109109

4

1,

1104,10859.8