Berkeley Physics Course: Electricity and Magnetism Volume 2

A very logical introduction to EM. The author starts only with the conservation of electrical charge and coloumbs law and using basic vector calculus concepts of field and divergence along with stokes theorem he derives maxwells first equation( diff form of gauss law ). He then uses concepts of line integral, potential and gradient and goes on to show how the conservative nature of the electrical force translates to path independence of work done in a static electric field and derives the static version of maxwells second equation. He takes an important look at applied theory especially in current analysis detailing the concept of resistance and basic series and parallel circuit analysis and how they directly derive from conservation of electric charge and conservative nature of the electrical force. A nice introduction to magnetism is completed by showing that it is a relativitic effect of electricity and defines the magnetic force accordingly. He then shows that unlike electricity the net flux of the magnetic field is zero and expresses it in differential form ( maxwells third equation ). By now you should know he is going to talk about line integrals as with electricity and shows that this is proportional to the current enclosed by the path ( static version of maxwell equation ) A nice digression on AC currents is explored and he then introduces induction as a prerequisite for modifying maxwells equations. He then shows that something is wrong with 2 of the equations above by showing that conservation of electric charge ( written in differential form ) leads to a contradiction in the above equations. He then shows how "adding" the term from the induction phenomena completes maxwells equations in a vacuum. A solution to maxwells equations is found resulting in the electromagnetic wave we hear so much about. The text concludes with chapters on electric and magnetic fields in matter. There is also a nice intro to special relativity. As with any text to gain understanding you must attempt a majority of the problems which range from very easy to interesting. A definite must for any physics buff.

I had the pleasure of using this book for my Honors Electricity and Magnetism class at Cornell. It was my second semester taking physics and I must say I really had a blast with that class, thanks to our professor Richard Galick second semester E & M will be one of my most memorable classes. Do not be misled by my enjoyment of the class, the homework exercises from this book were mostly all VERY CHALLENGING. I really I appreciated that Purcell takes the time in this book to thoroughly explain Physics (not Math which is just a tool used to wok on Physics), and doesn't waste so much time working out through endless formulas that don't get you any where; as our professor used to say "Let the Physics drive the Math, not the other way around".The only thing I don't like about this book is that it mostly all done in cgs units instead of SI. If you are a Physicist you'll find out how useful (for simplification reasons) this could be but if you are an Electrical Engineer like me it doesn't really help much.

Having used this book in college 24 years ago, I believe it remains the best overall introductory text book. It is written to truly give you understanding of the subject. In comparison, Halliday and Resnick, Feynman's notes, Jackson's (three of my favorite books) are respectively trying to teach engineering, provide insight, or impart mathematical rigor. Overall Purcell is not as original as Feynman but is a more complete and integrated coverage suitable for someone who wants to understand physics. It is not an engineering book so the problems are for thinking--really makes you think deeply about how the world is constructed. To solve lots of practical problems use H & R. Jackson is mainly useful to rounds out a few corners once you know the subject. I personally think it is the best intro book although the usual 10-12 weeks quarter or semester devoted to the teaching of this material is insufficient to really allow the subject to sink in--I'd take 3-4 weeks out over the summer and study this one subject alone before going to college. This will be extremely rewarding.

Edward Purcell shared the Nobel Prize in 1952, for his work on the discovery of Nuclear Magnetic Resonance (NMR, the basis of the politically renamed MRI). This book was written in the 1960's as part of the Sputnick induced panic which saw a great investment on the part of the US government in building up the domestic scientific educational infrastructure. Along with Reif's classic, "Statistical & Thermal Physics", this survives as a legacy of that era. Certainly, no one can contest the authority of the author. Nor can they claim that the book is out of date, as the laws of Electromagnetism have remained relatively constant. But this book is more than that, it is very well written and the clearest explanation of the phenomena of E & M, unified through the development of Maxwell's Equations, which is accessible to lower division students. For that reason it has dominated introductory honors classes in that niche for four decades. The typical inadequately prepared freshman/sophomore tends to find this book frustrating due to their lack of facility with vectors and multidimensional calculus. In fact, better prepared students will find this a perfect opportunity to develop familiarity with the application of basic vector calculus. While the book is elementary, it is rigorous.The text begins by introducing the basic ideas of electrostatics from the discovery of Coulomb's Law to its elegant formation by Gauss vis a vis the Divergence Theorem, developing the notion of the Electric Field and the Electric Potential function as simplifying mechanisms for applying Coulomb's Law. It then introduces the corresponding observations and principles for Magnetostatics. The interesting thing about this book is that in the development of Maxwell's Equations, which unify the Electric and Magnetic Field developments and yield the celebrated Wave Equation, Purcell stresses the idea that existence of the magnetic field is a necessary consequence that the influence of the electric field be made relativistically invariant. While he does not prove this, the concept is motivated.More advanced students will clearly want to progress to Lorrain & Corson or Griffith's, and then on to Jackson's tree-killing tome, but at each step up, motivation drops out and required mathematical sophistication increases.

This book must have been a work of love. The reader of it who fails to fall in love with electromagnetism would better change his direction of study, as he will not find anything better, including the marvellous Feynman's "Lectures on Physics". Following a more-or-less historical approach, except for the early use of relativity, the author strives to get the results from a full understanding of the physical situation. This is obtained by the use of very clever intuitive models. After that comes the mathematics, rendered natural and welcome. An outstanding example is the treatment of polarization of a dielectric sphere, where most of the physics is derived from a drawing! Another feature, to be found only in books written by great physicists, is the ability of stretching the argument up to its limit, getting results we wouldn't think possible with so little formalism. Problems are extremely good and real. The drawings, done by the author himself (so I read some! where) are very beautiful and helpful. Some of the exercises are of numerical character, motivating the use of computers. After meeting this book I could never teach introductory electromagnetism from another text. The author, Edward Purcell, is a Nobel prize winner who discovered, among many other things, nuclear magnetic resonance.