Download Lecture 1: Introduction to EM 1

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Lecture 1: Introduction
Instructor:
Dr. Gleb V. Tcheslavski
Contact: [email protected]
Office Hours: Cherry 2030
Class web site:
www.ee.lamar.edu/gleb/em/I
ndex.htm
ELEN 3371 Electromagnetics
Fall 2008
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Pre-requirements
Classes:
• MATH 3328 Linear Algebra;
• MATH 3301 Ordinary Differential Equations;
• ELEN 2311 Circuits I;
• PHYS 2426 Calculus Based Physics II.
Topics:
• DC and AC Circuits;
• Calculus-Based Physics in Electricity and Magnetism;
• Analytic Geometry and Calculus II including Vector Analysis;
• Calculus III including Partial Derivatives, Double and Triple
Integrals, Vector Fields, Stoke's Theorem, and Vector Calculus;
• Differential Equations;
• Linear Algebra.
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Textbooks
Required:
Elements of Electromagnetics, Fifth
Edition, Matthew N.O. Sadiku, Oxford
University Press, Inc., 2010, ISBN 978-019-538775-9.
Karl E. Lonngren and Sava V. Savov,
Fundamentals of Electromagnetics
with MATLAB, SciTech Publishing,
Inc., 2005, ISBN 1-891121-38-3.
Recommended:
Robert E. Collin, Antennas and Radio-wave
Propagation, Mcgraw-Hill College, 4th
edition, ISBN 0-0701-1808-6.
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Class structure and your grades
Five to ten homeworks, two exams, and the final exam.
Exams are closed books/notes.
Homeworks and exams are covered by the Academic Honor Code
Attendance Policy: Exams attendance is mandatory with exemptions
of individual or family emergencies, health conditions etc. Valid
documentation will be required. You are required to attend all lectures!
Your attendance may affect your final grade.
NO late homework will be accepted!
Tentative grading weights:
Homework
Exam 1
Exam 2
Final exam
20%
20%
25%
35%
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Styles, notations, legends…
1. Colors:
Normal text and formulas
Something more important (imho)
Important formulas and results
Very Important Formulas
Miscellaneous
2. Equations notations: (2.17.3)
Lecture # Slide # Formula #
3. [xx] next to the formula indicates units.
4. Matlab logo:
ELEN 3371 Electromagnetics
indicates the corresponding Matlab function
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What’s this course about?
• We will study electric and magnetic fields.
• We review STATICS (zero or low frequency).
• and study DYNAMICS including Maxwell’s and Helmholtz
equations, wave propagations, antennas, etc.
The basic sources of electromagnetic (electrical) forces are stationary and
moving electric charges, which exert forces on other stationary and moving
electric charges. To study these forces, the concept of force fields has
been devised.
– When charges are stationary, the force field is an electric (electrostatic)
field.
– When charges are moving with a constant velocity, the force field is a
magnetic (magnetostatic) field.
– Accelerating charges produce electromagnetic fields.
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Statics
Definition: f = 0 [Hz]
The electromagnetic field splits into two independent parts:
Electrostatics: (q, E)
Static charge
Magnetostatics: (I, B)
Constant current
The static approximation is valid when the dimension
of the circuit is small compared to the electrical wavelength.
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Concepts of frequency/wavelength
Example: a circuit working at 60 Hz.
0 = c / f
- wavelength in vacuum
c = 2.99792458  108 m/s
f = 60 Hz
This gives: 0 = 4.9965106 m
= 4,996.5 km
Most circuits fall into the static-approximation category at 60 Hz.
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Some history
Charge was discovered by the Ancient Greeks (about 600BC)
who found that rubbing fur on various substances, such as
amber, would build up an electric charge imbalance.
The Greeks noted that the charged amber buttons could
attract light objects such as hair.
The Greeks also noted that if
they rubbed the amber for long
enough, they could even get a
spark to jump.
The word electricity derives
from ηλεκτρον, the Greek word
for amber.
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Some history (cont)
Two glass rods rubbed with silk and placed near one another were
observed to repel each other.
On the other hand, if a resin (plastic) rod rubbed with fur is placed
near one of the glass rods, the force was attractive.
Benjamin Franklin (mid 1700’s) is credited with naming electrical
charge; that appearing on the glass rod was designated positive and
that on the resin (plastic) rod, negative.
Franklin was well known for his
many quotations and his
experiments with electricity
ELEN 3371 Electromagnetics
Fall 2008
Folks contributed to the research
on electricity
• Luigi Galvani (1737–1798),
• Alessandro Volta (1745-1827),
• Michael Faraday (1791–1867),
• André-Marie Ampère (1775–1836),
• Georg Simon Ohm (1789-1854).
• Nikola Tesla,
• Thomas Edison,
• George Westinghouse,
• Werner von Siemens,
• Alexander Graham Bell
• William Thomson (lord Kelvin)
•…
ELEN 3371 Electromagnetics
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Your
picture
here?
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