Electrodynamics Definition and 405 Threads

Homework Statement The xy-plane serves as the interface between two different media. Medium 1 (z < 0) is filled with a material whose µr=6, and medium 2 (z > 0) is filled with a material whose µr=4. If the interface carries a current (1/µ0)ˆy (y- hat) mA/m, and B2 = 5ˆx (x-hat) + 8ˆz (z-hat)...

Homework Statement Two particles A and B each carry a charge Q and are separated by a fixed distance D. A particle c with charge q and mass m is kept at the midpoint of A and B. If C is displaced perpendicular to AB by a distance x where x<<<D, find the time period of the oscillation of the...

Hello Everyone, Could anyone please explain the difference between the conduction current density (J=σE) and the convection current density (J=ρvd)? I really appreciate any examples or applications to further elaborate these two theories. Note: vd is the particles' average drift velocity...

Homework Statement The rectangular parallelepiped with sides ## a > b > c ## is filled with charge of constant density ## \rho ##. A sphere of radius ## 2a ## is constructed with its center at the origin. Find the flux through the surface of this sphere Homework Equations $$ \oint E \cdot...

I try to learn electrodynamics as theoretical physicist, Now I study from Griffiths, I find it very good book and do the job! but the problem I need to learn electrodynamic to do future topics like Quantum Electrodynamics, and Pollack I find it good and modern, so my question is what is the best...

Hi, I recently ordered the fourth edition of "Introduction to Electrodynamics" by Griffiths. However, I received the international version of the textbook. In my upcoming course, our homework will be made up of problems coming directly from the original version. So, are the problems in the...

Homework Statement An infinitely long wire carries current I=I_0sin(wt). A distance a from this wire is an w by l loop with resistance R with induced voltage V and induced current i. Find the induced voltage and current in the loop. Homework Equations Faraday's law is given by \varepsilon =...

I am trying to sketch the electric field E in snapshot of a linearly polarized laser beam. Is it correct that the E vectors bend from vertical to longitudinal near the cylindrical surface of the beam, and that all field lines within a half wave segment are closed loops?

Hi, I've 2 em texts: Purcell, ( Electricity&magnetism ) and the Griffiths (intro to electrod.) On which of the two, is best to study ?

We have materials that have negative effective permittivity and permeability. In such materials, when the product of permittivity and permeability is negative, solving the wave equation yields a wave with a purely imaginary wave number. Does this mean complete attenuation of the wave ?

I was solving the problems given by Griffith in his book 'Introduction to Electrodynamics' and stumbled across this question. "Because sigma (conductivity of the medium) is a function of position, the equation 7.5 does not hold" --i get this point; current density isn't constant and so its...

In this thread I gather my questions concerning derivations in the textbook of equations and of solutions to the exercises. I hope every student and professional will benefit from this thread. I'll start in the next post.

I am studying electrodynamics, in a few more months I have the qualification exam. The guide text is classical electrodynamics, Jackson. I find that book is higher my current level. I have the math tools, but what book do you recommend to use before the Jackson.

Hello! I am an undergraduate currently enrolled in a course on theoretical physics. One big part of the course is on the classical field theory of electromagnetism(on its covariant formulation using Lagrangians mostly). So, I would like to ask which are some good books on the subject. Thanks in...

There are many website about the apparatus of Hertz's experiments, i.e. http://www.sparkmuseum.com/BOOK_HERTZ.HTM http://earlyradiohistory.us/1901hz.htm http://people.seas.harvard.edu/~jones/cscie129/nu_lectures/lecture6/hertz/Hertz_exp.html There are many pictures showing the apparatus of...

Hi everyone. As the title says, I am looking for a good exercise book covering the topic of relativistic electrodynamics since the beginning. Even lecture notes from some universities would be great given that solved problems of increasing difficulty are provided. Do you know some book of this...

hello this is my first topic here and i hope good discussion or answer to my question As i understand the Maxwell equation keep its form in all frames so why i need to make a covarient formulation form of electrodynamics ? for example what the covarient form of continuity equation give me !

Homework Statement Homework Equations ##\oint \vec{H} \cdot d\vec{l} = I_{free,enclosed}## ##\vec{B} = \mu_0 (1+\chi _m)\vec{H}## The Attempt at a Solution I found the magnetic field inside to be ##\vec{B} = \mu_0 (1+\chi _m)\frac{Is}{2 \pi a^2} \phi##. But why can't I use the same equation...

Hi, What book could you recommend for a first course in classical electrodynamics? Thank you

Dynamos and transformers have inductor coils reacting with changing magnetic fields and importing energy into the circuit in form of induced current 1. What about the counterpart of above principle in case of capacitors? 2. Will capacitors interact with...

Hello, friends! My textbook, Gettys's Physics, says that the Lorenz gauge choice uses the magnetic vector potential $$\mathbf{A}(\mathbf{x},t):=\frac{\mu_0}{4\pi}\int \frac{\mathbf{J}(\mathbf{y},t-c^{-1}\|\mathbf{x}-\mathbf{y}\|)}{\|\mathbf{x}-\mathbf{y}\|}d^3y $$and the electric potential...

Hey guys, Can you please refer some good books to refer to in studying relativistic Electrodynamics (introductory parts), covering the Maxwell's equations in tensor form the L-W potentials and other aspects. FYI am just a beginner in relativistic Electrodynamics. Thanks for the help.

Hi. In the (mainstream) books of electrodynamics I know, the electric and magnetic fields are introduced as force fields normalized to a charged test particle of 1 C. This makes those fields appear as an unnecessary, but convenient mathematical tool. They cannot be measured in the absence of...

Hi. Assume a long hollow wire that both carries a nonzero net charge and a current. Is it still true that all charge sits on the outer surface of the cable and that the empty space inside is field-free (Faraday cage)? I know proofs of those facts in electrostatics using Gauss' theorem, but they...

Homework Statement Hello! I have a question about the following problem: Two point masses m1 and m2 are attached to isolating wires to point P. They are both positively charges (charge Q1 and Q2) and in the picture you can see the situation at equilibrium. What is the proportion of the...

Here is a quote from this website: My question is: is this derivation of length contraction considered to be sound and correct today? Are they treated in modern textbooks?

In two months I'm going to take one Physics exam which covers all the undergraduate courses and I must confess I feel quite overwhelmed by the amount of content that there is to be reviewed. In truth I feel that for the purpose of preparing for one exame like this it is not really productive to...

[Moderator's note: changed thread title to be more descriptive of the actual question.] Consider Maxwell's action ##S=\int L## over Minkovski space, where the Lagrangian density is ##L = -\frac{1}{4}F_{\mu\nu}F^{\mu\nu}##, and the Electromagnetic tensor is given by ##F^{\mu\nu} = \partial^\mu...

I hope this is right place to post this. I just wanted to get this off of my chest. I am frustrated, and depressed because I am an outsider to the physics community. I am posting this with the hope that somebody else might be able to add perspective to my situation. I apologize if that's...

I am not sure what does Jackson want to talk in section 9-6? Is that just a review of something discussed previously? Chapter 9 is talking about radiation, and later about multipole expansion.

Hi guys, I'm just curious about how does Classical Electrodynamics by Hans Ohanian and Electromagnetic Fields by Ronald Wangsness compare? I know Griffiths is like the way to go when it comes to EM, but personally, I find his book too hand wavy and the explanations are sometimes lacking, so I...

Hi everyone here. I have my question in the following attached pdf file

I got into a top 10 Ph.D program yah I know yay for me and I'll be starting this fall. As I always I'm planning my course work way in advance and figuring out how to tackle it. For my required electrodynamics class they use Jackson. I heard a lot of bad things about that book. When I took upper...

Homework Statement I am studying for an Optics exam and in one of the practise tests is the following question: "Over what frequency range are Maxwell's equations valid?" Homework Equations Maxwell's Equations The Attempt at a Solution I've searched through my Griffiths Intro to...

Currently I'm in the last year of the Physics course and I've been thinking about working in a project of undergraduate research, specifically in Statistical Physics. Two years ago I've already done a project like that in Fluid Mechanics combined with Gauge Theories and in that project I've...

Can anyone suggest me a book on quantum electrodynamics for beginners? Thanks in advance

Is there a general solution explicitly worked out for how a monopole and electic charge would interact? Of course the electro-static solution is that there is no interaction, but the electro-dynamic solution would not be so trivial, as moving charges/monopoles would induce magnetic/electic fields.

Homework Statement Prove that a current density J(r, t) such that ∇ × J = 0 implies the magnetic field B = 0.Homework Equations Maxwell's equations, vector calculus The Attempt at a Solution I've played around with Maxwell's equations and with the properties of vector calculus but I can't...

I have read in Griffiths electrodynamics that divergence of 1/r^2 is delta function and I thought it was the only special case...I have understood the logic there... but a question came in mind...what would happen in general if the function is 1/r^n ...where n is positive integer>0...because the...

Homework Statement How do I find the total charge from a material with a charge density given by \rho =10^{-9} \text{cos}\left ( \frac{z}{z_0}\right ) C/m^3 that exist between \frac{-\pi}{3}z_0<z<\frac{\pi}{3}z_0. Homework Equations None I can think of. The Attempt at a Solution Attempt #1...

Hey All, In deriving applications of Maxwell's equations in advanced electromagnetics, it seems like one is exposed to almost all of the vector calculus identities in the book! (or at least on the current Wikipedia entry :smile:). Personally, I'm a non-traditional learner, and grasp advanced...

I'm really conflicted with this one, I found many sources that state that Newtons 3rd law does not hold in electrodynamics, reasonable sources with mathematical proof(example). And as a student who just finished Physics I and taking Physics II course, this is really confusing... but when I think...

Hello. I'm supposed to be an electrical engineer but between my ears there is physics! In my sophomore year at Purdue (1964) I got tangled up with the superposition theorem and its lack of shielding between charged particles. I fashioned a model for electrodyamics that included shielding. In...

Dear All, I have this semester an electrodynamics course, one of our tasks is to write a report topic about any related to the course. Any suggest will be appreciated...Thanks in advance

Friends, can you suggest for some good books which can be studied in graduate level. Except Griffiths, I've completed it.

Homework Statement I am trying to solve Problem 2.45 in Electrodynamics by Griffiths, however, my answers were different from those in the book, I am suspect I got a missing step but I could not find it, so here is the Given Problem Find the charge density \rho given by a potential...

I am currently reading Modern Electrodynamics by Andrew Zangwill and came across a section listing some delta function identities (Section 1.5.5 page 15 equation 1.122 for those interested), and there is one identity that really confused me. He states: \begin{align*} \frac{\partial}{\partial...

Hello everyone! I'm stuck at an Electrodynamics problem and would be happy for some guidance 1. Homework Statement A magnetic dipole \vec{m}(t)=\vec{m}_0cos(\omega t) at the origin can be described by the current density \vec{j}(\vec{r},t)=-\vec{m}(t)\times\vec{\nabla}\delta(\vec{r})...

Homework Statement http://physics.columbia.edu/files/physics/content/Quals2010Sec2.pdf Problem 1 Consider a rigid, ideally conducting sphere of radius R, with total charge zero. The sphere rotates with angular velocity Ω, ΩR<<c. Suppose a dipole magnetic field threads the sphere. the dipole is...

Homework Statement A circular loop of radius R is on the xy plane and the center is at the origin, the current is flowing in a counter-clockwise manner. a) Let Q=(a,0,a) be a point such that a>>R. Find Br and Bθ at Q. b) Let Q=(ha,0,0) be a point on the x-axis such that h<1. Find the vector...