E&m — 231 discussions

Ok, this class is killing me. The only college physics classes I've taken are physics 1 and 2. Then I walked into this class and it seems like I'm missing some physics and math classes. I meet the prerequisites, which are only Calc 3 and Physics 2. But this book we're using (from 30 years ago...

Homework Statement A spherical charged ball of radius "a" has an empty spherical cavity, of radius b<a, at its center. There is no charge outside the ball and no sheet-charge on its outer surface. The (radial) field has given value Ea on the outer surface; inside the ball it is given as...

Homework Statement A charged disk of total charge "Q" and radius "a" lies in the xy-plane, centered at the origin. The surface-charge density distribution is nonuniform, having the surface-density, at any point inside the disk at distance "r" from the center of the form σ(r)= m x r^2 , m...

"hidden momentum" There's an interesting thing in E&M which is referred to as "hidden momentum" in this paper: Babson et al., Am. J. Phys. 77 (2009) 826 http://www.ate.uni-duisburg-essen.de/data/postgraduate_lecture/AJP_2009_Griffiths.pdf The simplest example is a magnetic dipole immersed in...

I just started an E&M class and right from the beginning the notation seems so confusing it has to have been done as a joke. Trying to do a problem I run into about 10 different r's I have to keep track of. Capital R Lower case r Lower case r prime The r in spherical coordinates The "squiggle" r...

I'm just wondering, but what sort of difference is there between the electromagnetism that Electrical Engineering majors learn and the electromagnetism that Physics majors learn?

Hi, I'm looking for some additional reading material while preparing for an E&M course. I'm going through Jackson and Griffiths, and I'd like to read a few scientific papers that will be good "E&M exercises." Anybody have papers in mind? Any suggestions for an intro to plasma containment?

Hello all, Long story short, I am taking E&M course that uses Jackson, but in undergrad I only took 1 quarter of E&M (electrostatics). With classes about a month away, what would a good way to prepare. I realize that it is not enough time, but I figured some prep would be better that nothing...

Hi all, I am a graduate student in physical chemistry and I have discovered a fairly large hole in my knowledge. I am designing some experiments that will study the behavior of ions in magnetic fields. I don't have much background in E&M fields past a general physics course. Do you have any...

Homework Statement The following charges are located inside a submarine: 2.00 µC, -9.00 µC, 27.0 µC, and -54.0 µC. (a) Calculate the net electric flux through the hull of the submarine. Homework Equations Flux = q/e0 The Attempt at a Solution I found the net charge, which happens...

could any1 recommend a good E&M book that might be worth reading after having just finished Griffith's book on the subject... so probably a book a little more advanced than Griffith's

This summer I plan to self study quite a bit and want to learn as much as I can. I'm an EE major and have taken Calc 1-3, and DiffyQ/Linear algebra as well as intro physics classes. I will be taking classical mechanics in Spring 2013 but wanted to dive into Griffiths E&M book this summer. Is...

Homework Statement Can you derive Maxwell's equations from conservation of charge, energy and angular momentum for E&M fields? Homework Equations The Attempt at a Solution

we are learning a lot about circuits in freshman physics 2 - does junior/senior E&M do circuits - or do i need to take a circuit course if i want to learn more about circuits beyond freshman physics 2? thx

Does anyone know of any way to compartmentalize electromagnetism into much simpler material to work with? Let me clarify what I mean—Mechanics is very easy (at an undergraduate level) because knowing ∑F=ma and basic knowledge of Calculus and Differential Equations can lead to instantaneously...

The book I currently use for my class is not great with very few examples, watered-down theory, and is bloated. I've searched the forums and found that Halliday and Serway are well received, but I still don't know. Even though my course is supposed to be calculus-based and all the concepts are...

Hey guys and, of course, ladies. I was wondering if anyone knows the job outlook for Electrical Engineering concentrating on DSP and/or RF/Microwaves and E&M. I'm planning to get my M.S. EE at NYU-Poly on either one of the path. I would like to know: which of the 2 has a better job...

I'm learning about polarization and something has me a little confused. I feel like I understand polarization: blocking out all the light except for those waves in a particular direction: horizontal, vertical, e.g. But if a "single" light wave is made of a propagating electric and magnetic...

My school opened a new class this semester (Labeled as "Lasers and applications", but the syllabus has it as "Nonlinear optics and Ultrafast physics"), and I figured that as a junior-level physics major I should've been able to take it, since the course itself doesn't list any prerequisites...

I don't know why, but I just can't get into E&M. I didn't find it interesting as an undergrad, and it's not interesting to me now as a grad student. However, I need to know the material--gotta pass the quals!--and I even want to know the material ('cause it's an important part of physics and I...

Homework Statement Consider a large solenoid aligned with the z-axis with a uniform magnetic field inside given by Bo = Boz[hat]. Contained WITHIN the solenoid is a very large parallel plate capacitor and the plates (one at the x=0 plane and the other at the x = d plane) have surface charge...

So I'll be taking undegrad E&M 1 next semester and was looking for a good book to prepare for it before the semester starts. People seem to like Griffiths and Purcell generally. Shwartz also seems to have some good reviews (and is quite cheap) on Amazon but I'm not quite sure what level it is...

I_c = A [ e^{(qV_b)/kT} -1] A is a constant How can i derive it? Where can I find more about this equation? Online source would be great.

I want a MV Calc book that has a good covering of vector field operations, mostly for studying Maxwell's equations and stuff later on. Rigor would be nice; I would prefer a book that proves most theorems, but not one as crazy as Spivak (I have only a few months!). Interesting theoretical...

Next semester I will be taking the following courses - Elementary Differential Equations Methods for the solution of elementary types of ordinary differential equations with geometrical, physical and chemical applications. - General Chemistry I (with lab) Fundamental principles of chemistry...

Homework Statement There is an electromagnetic potential four-vector, whose components are (V,Ax,Ay,Az) where V is the electrostatic potential and A is the magnetic vector potential. There is a time-independent electromagnetic field in the lab frame. Its electric and magnetic potentials are...

Hello, so I was asked a question in two parts (Peskin & Schroeder problem 2.1). The first part asked me to derive the source-free Maxwell's equations from the action: S=\int{d^4 x \frac{-1}{4}F_{\mu\nu}F^{\mu\nu}} Given that the vector potential itself is the dynamical variable. I derived...

Just took my first E&M physics 2 test tonight, it was almost all conceptual. I feel like such a fool because it seemed basic yet most of the questions I felt uncomfortable with. My last physics class was more of the equation hunt type, working in symbols, see how things relate mathematically...

Hi, guys. For an E&M/quantum mechanics problem I have to integrate the series below: Homework Statement Integrate \int{r^{2}e^{y r} \, dr}.2. The attempt at a solution Using integration by parts and and "differentiating under the integral" give the same answer: I= \frac{2...

Hey so I'm trying to self study for both AP Physics exams for May 2012, and I've been going through halliday & resnick 7th ed. as a text, however, I feel that this book isn't helping me so much for the mechanics side of things (as I haven't begun to study E&M stuff yet) for two reasons. First...

I'm looking for a Electricity and Magnetism (and beyond if possible) textbook that suits my capabilities better. I just read "Electric flux is proportional to the amount of electric field lines penetrating some surface" in my current textbook. I find that this is for the mathematical incapable...

Hello, I'm about to start university as an electrical engineer student, and I'd like to have a better grasp of the theory behind the stuff we'll see in the program. I've been through Cegep here ( I think it's the equivalent of the last high school year + the first University year in the...

Hi, I looking for books that have practice problems (with explanations would be nice) on general introductory level Calc. based Classical Mechanics. And for Electromagnetism I'm looking for an introductory book that has practice problems. I haven't taken Multivariable Calc. yet (I'll be...

Help with E&M? 1) http://tinyimage.net/images/25790944428468568236.png I don't even... The answer is B.. What should I review?? 2)http://tinyimage.net/images/81684598844478119651.png Why can't I use the formula V^2/R for this one?? answer C btw ( I did get it right, but just because I...

Do you guys think it's a good idea to take both E&M and Mechanics at the same time in the summer?

Homework Statement This isn't the whole homework problem but I need to show that (p dot gradient operator)E is equal to Gradient operator(p Dot E) Homework Equations P= Dipole Moment E= non constant electric field. The Attempt at a Solution Like I said this is the last part of...

I have to perform a "lab practical" tomorrow for my E&M class and it involves using a multimeter to determine what is inside a "black box" - either a battery/resistor combo or a capacitor. Homework Statement Taken from the lab practical write-up: "You’ll be given a box with two...

I am currently a junior in high school taking physics A. I find it very easy and natural and have an A for 1st semester and a 97 on the midterm. I want to take AP physics but i am not sure which one. In college i am most likely going into construction so I will need a lot of math and physics...

Homework Statement Δ<--- the gradient X<---cross product (o∫) closed integral [SIZE="4"]∫((ΔT)Xda = [SIZE="4"](o∫)-Tdl btw what is the realtion ship above called? Homework Equations da= axdydz +aydxdz +azdxdy dl=axdx + aydy + azdy The Attempt at a Solution not sure where...

Is this a bad idea? I want to get my intro courses out of the way, but don't want to sacrifice a full understanding.

I am studying EE and want to know more about electric and magnetic field theory in more detail probably at the Quantum level.i realized that studying physics will suffice that but i am getting negative feedback from others that it will be not good for my career,they are saying that these things...

1. Homework Statement How much work does it take to construct a conducting sphere of radius 'a' and charge '+q' by pulling charges ('dq') from an infinite distance? Then construct another conducting sphere of radius 'b' and charge '-q' around the sphere of radius 'a'. Given 'a'<'b'. 2...

1. Two metal plates, 10 mm thick, are held a distance z=40 mm apart with a potential difference of 10 V across them. As you look at them the positive plate is on the left. In between the plates is a vacuum. Ignoring edge effects and assuming unit area for the plates, calculate both the charge...

With out having to use the Dirac equation for a photon, is there any formalism similar to Fermi's golden rule, except for the E&M wave equation derived from Maxwells' Equations? I have a simple system whose wave equation solutions can be nicely expressed in terms of an eigenfunction...

Homework Statement First of all, sorry for my bad english. I have this problem and I've been trying to come up with something for 1h without success. A circuit is "given" 100kW (100 000W) The total resistance of the cables the electricity goes through is 5 ohms. The voltage difference...

I'm taking Calc 1 and Physics 1 this semester. Things are going well, although Physics can be difficult at times. Next semester I would be taking Physics 2 and Calc 2 at the same time. I keep hearing from other students that this is a bad idea. Can someone shed some light?

My end goal is to analytically or numerically calculate the magnetic field inside and around a square conductor that has connection points at the top and bottom with a voltage applied. Are there any software packages (mathematica, or even just C) that can do this given ANY current density in...

Hi all! I graduated last year with my BS in physics and math. I am kind of confused about my choice to do physics in grad school, even though if I get my phD I probably wouldn't want to go into academia. I would like to do research in a government lab. I am comfortable with those theoretical and...

Homework Statement We have a rectangular box with diagonal corners at (0,0,0) and (-1,2,3)cm. We place charge inside this box with distribution, ρ(r)=2x-3(z-1) with units of nC/m3. What is the total charge inside this box? Homework Equations The Attempt at a Solution I have...

Homework Statement The problem statement is in the attached .png file. There are a few equations involved which would have taken a decent amount of time to type out. Homework Equations The Attempt at a Solution I understand Maxwell's equations, and wrote out all 4 assuming there are no...