A note to
to instructors using FIELD AND WAVE ELECTROHAGNETICS.
Dear Colleague:
As teachers of introductory electromagnetics, we
we are all aware
As
of two facts: that most students consider the subject matter
difficult
difficult, and that there are numerous
numerous books
books on the market
dealing with this subject. It is understandable that students
s~udents
find electromagnetics difficult. First of all, the subject
ma
tter is buil
matter
builtt upon abstract models that demand
demand a good mathematical background. Second, before the course on electromagnetics, students who
who have
have studied circuit theory normally
encounter functions of only one independent variable, namely,
time'
time; whereas 1n
in electromagnetics they are suddenly required
require~ to
t~
deal'with
deal with functions of four variables (space and time). This
ThIS is
IS
a big transition,
tranSition, and visualization problems associated with
solid geometry add to the difficulty. Finally, students are
often confused about the way the subject matter is
Is developed,
most
even after they have completed the course, mainly because most
books do not provide a unified and comprehensible approach.
As
As I point out in the Preface of the book, the inductive aptenlls to
proach of beginning with the various experimental laws tends
be fragmented and lacks cohesiveness, whereas the practice of
writing the four general Maxwell's equations at the outset
without discussing their necessity and sufficiency presents a
major stumbling block for learning. Students are often puzzled
about the structure of the electromagnetic model. I sincerely
believe that the gradual axiomatic approach based on Helmholtz's
in this book provides unity in the gradational
theorem used in
development of the electromagnetic model from the very simple
model for electrostatics. Although a rigorous mathematical
proof of Helmholtz's theorem is relatively involved (not included in the book), the physical concept of specifying both the
flow source and the vortex (circulation) source in order to
quite simple.
define a vector field is Quite
qoestions are provided at the end of each chapter.
Many review ~Destlons
designed to
to review and reinforce the essential material
They are deSigned
1n
in the chapter without the need for a calculator. You may
may wish
to use them as a vehicle for discussion in class.
I have tried to.m~ke
to make the problems in each chapter meaningfUl
meaningful
and to avoid trlvlal
This solutions
trivial number-plu~1ng
number-plu~ing types.
manual gives the solutions and answers to all the problems'in
problems' in
the book. I hope it proves to be a useful aid in teaching
from the book. Answers to odd-numbered problems are included
in the back
back of the book.
1I realize that, no matter how
how careful I have endeavored to be,
occasional errors may
may still exist. I should be grateful if
you would be kind enough to notify me
me a3
as you
you discover them
either in the book or in this manual.
Sincerely,
David K.
K. Cheng
and Computer Engineering
Electrical and
Department
Syracuse University
Syracuse, NY 13210
13210
(For the use of instructors only.)