Fields Definition and 1000 Threads

Homework Statement A particle of mass m and charge -q moves in a circular orbit of radius R about a fixed charge Q. The angular frequency for the orbit is given by \omega_0^2 = \frac{qQ}{4 \pi \epsilon_0 m R^3} A uniform magnetic field of magnitude B in a direction perpendicular to the plane...

Homework Statement An ion of mass m and charge q is accelerated from rest through a voltage of ΔV. It then enters a magnetic field. Determine the mass of the ion in terms of the measurable quantities: q, ΔV, (B^→) , and x. Homework Equations The Attempt at a Solution m =...

We know that a direct current generates a magnetic field which surrounds the wire in circular patterns (right-hand rule). However when alternating current runs through a wire, no actual electrons are transported from one end to the other but rather they "vibrate" so to speak and transmit this...

A lot of below might be a question of semantics however it helps to understand better, I am a novice: 1. What's the difference between a field and a dimension? A field is present at all points in time and space, ...so is a dimension. why don't we call/label a field as a dimension? 2. or...

Momentum and magnetic fields are both vector quantities. If two bodies with the precise mass and speed collide head on (θ = 0), then momentum is conserved (they come to a complete stop) and energy is conserved (the kinetic energy is changed to other forms). What then happens in the case of...

You place a conductor in an electric field. The charges inside the conductor will relocate, to form an opposing electric field which cancels the outside field, making the field inside the conductor zero. However, surely there's a limit to how big an opposing field the charges in the...

This is a really basic question, but... Say I have a massive scalar field obeying the Klein-Gordon equation linearized about flat space, \partial_t^2 \phi + (k^2 + m^2)\phi = 0. This has solutions \phi \sim e^{\pm \sqrt{k^2 + m^2}t} and the sound speed should be \omega_k/k =...

Homework Statement At which location will the electric field between the two parallel plates of a charged capacitor be the strongest in magnitude? a. near the positive plate b. near the negative plate c. midway between the two plates at their ends d. midway between the two plates nearest...

A gravitational field and a magnetic field both decrease in strength at the distance squared. They are two totally different forces so why the correlation?

I have taken my Gauss surface as the front of the shape, with E_1 coming through uniformly. I get the right answer for the charge inside the shape, but I'm unsure about b. I imagine a situation that I've drawn could be possible, but I've never seen it before, so I do not know. I'm thinking that...

Homework Statement z+ up with E field, y to the right, x out of the page with B field particle released from rest at (0,0,0) with only initial y velocity y=(E/B)t or initial y=(E/2B)t Homework Equations can you suggest a good differential equations text...

After writing this, I realized that I really have no idea what I'm going on about. Mainly, I don't understand the significance of it being an insulating object. I gather this means the charge is distributed uniformly throughout the object, rather than at the surfaces, but I don't know how I can...

It is asked to find the electric flux through a "gaussian" sphere which has a point charge (-3 microcoloumbs) enclosed with the radius of 0.2 m ... I can shortcut this and use Flux= q Enclosed / e0.. However, i want the other approach using the formula Flux = ∫ E da... I know that E is constant...

Homework Statement A parallel plate has p.d. V with one end 0V and the other +V. B-field of strength B has direction along plates. An electron is released from rest at 0V plate. Show that if V is less than e(DB)2/(2m) the electron will not reach the other plate. Homework Equations...

Homework Statement I am going through the example problems in the book and it shows me how to find the electric field of a line of charge, which is this http://imageshack.us/a/img24/8932/img0303fq.jpg I get to this part where they change ΔQ to (Q/L)ΔY...

With my term-end examinations fast-approaching, I sat down to revise my entire senior year physics syllabus. As I was reading through electromagnetic induction, I found myself in the same state of utter confusion that I found myself in when I first studied about Lenz's Law and Eddy Currents. But...

I don;t really know how should I "tackle" this problem. The only thing I got is the answer for a) i) 1.9 * 10^11 J. It's a problem from IB Oxford Study Guide. http://img59.imageshack.us/img59/4986/fiz6.jpg I would be very grateful if You could help :) Thanks!

Homework Statement Prove Z[x]/pZ[x] is an integral domain where p is a prime natural number. Homework Equations I've seen in notes that this quotient ring can be isomorphic to (z/p)[x] and this is an integral domain but I don't know how to prove there is an isomorphism between them and...

One component of a magnetic field has a magnitude of 0.0266 T and points along the +x axis, while the other component has a magnitude of 0.0648 T and points along the -y axis. A particle carrying a charge of +2.96 × 10-5 C is moving along the +z axis at a speed of 4.71 × 103 m/s. (a) Find the...

Homework Statement An example problem I am reading is about the electric field of a uniform ring of charge. I attached the diagram provided in the problem. What confuses me is that the electric field lines in the y-direction cancel out. Wouldn't the fields have to cross, if they were to...

Hey yall. This is a question from my homework but it's so basic that it's just to help with the concept for me. So the question is this: A small object A, electrically charged, creates an electric field. At a point P located 0.250 directly north of A, the field has a value of 40.0 directed to...

Imagine nine vertical and parallel lines drawn side by side. They represent infinite planes of uniform voltage. The first line has 0 V. The 2nd line has 1 V. The 3rd has 2 V and so on, with the 9th line having 8 V. The distance between each line is 1 cm, which is 0.01 meter. There is an...

Homework Statement 1st Problem (a) Consider the electric potential V = C . r, where C is a constant vector. Find the electric field E(r). (b) For a given uniform electric field E = E(0)z^, using part (a) find the electric potential for this electric field...

Homework Statement A small conducting sphere of mass 5.0x10^-3 kg attached to a string of length 20 cm, is at rest in a uniform electric field E. There is a charge of -5.0x10^-6 coulomb on the sphere. The string makes an angle of 30° with the vertical. Calculate the tension in the string...

Homework Statement one capacitor is charged until its stored energy is 4.0 J, the charging battery then being removed. a second uncharged capacitor is then connected to it in parallel. if the charge distributes equally what is now the total energy stored in the electric fields? where the...

Homework Statement The Lagrange method does work for some velocity dependent Lagrangian. A very important case is a charged particle moving in a magnetic field. The magnetic field can be represented as a "curl" of a vector potential ∇B = ∇xA . A uniform magnetic field B0 corresponds to a vector...

Hello, I have a few questions (with regards to conducting hollow spheres) . 1: What is the difference between a charge in the sphere and an excess charge coming out of the sphere or the charge resting on the outside of a sphere? 2: Image a conducting sphere that has a shell of a small...

Hi I am working on a optimization problem involving vector fields. In order to define a objective function I need a measure (scalar quantity) of some properties of the vector field. The vector field comes from a finite element analysis, that is the vector field is calculated on a discretized...

Can anyone tell me why it is necessary to express a field as annhilation and creation operators? I just don't see why we need a field to explain the creation of particles in relativity, after all two colliding particles with enough energy produce some more.

Although I retired from active physics research almost 2 decades ago, there's a question that has annoyed/intrigued me for almost 40 years... In Classical Field Theory, matter has 2 intrinsic properties, namely mass and charge. Given Newton's 2nd Postulate, {\bf F}_{net} = m {\bf a}, I've...

Hi, A current carrying wire creates a magnetic field around it, as shown here: http://courses.ae.utexas.edu/ase463q/design_pages/fall02/wavelet/3_sour8.gif As far as I am aware this usually doesn’t cause a power loss. Even if there is a flux on a nearby conductor there will be no power loss...

Homework Statement Let f(x) = x6 + x3 + 1 in Z_2[x]. Show that f(x) is irreducible. Let E = Z_2[x]/(f(x)), and let αdenote the image of x in the quotient field. Show that E* = <α>. Homework Equations I have solved the first part, but what does E* mean? I have seen the asterix in...

Homework Statement Four charged particles are at the corners of a square of side a as shown in the figure below. (Let A = 5, B = 2, and C = 7.) Homework Equations The Attempt at a Solution Well, I first found the electric due to each particle individually...

Homework Statement In the figure below, determine the point (other than infinity) at which the electric field is zero. (Let q1 = -2.45 µC and q2 = 6.50 µC.) Homework Equations The Attempt at a Solution Here is a little commentary my author gives on this problem: Each...

Homework Statement An isotropic quasimonochromatic point source radiates at a rate of 100 W. What is the flux density at a distance of 1 m? What are the amplitudes of the E- and B- fields at that point? Homework Equations I think (but not at all sure) that the equation for flux density...

Gauss equations state that the flux of a gaussian surface is equal to the sum of all the electric field times the surface area. Although he stated this in theory, how was he able to prove it possible. What measuring device do people use to prove that this theory is correct?

Homework Statement see attachment for question wording. a) find acceleration b) find horizontal displacement c) find final velocity vx=4.0*10^6m/s ε=4.0*10^2 N/C Δdy=0.02m mass of electron = me = 9.11*10^-31kg charge of electron = qe = -1.6*10^-19 C Homework Equations suvat...

Homework Statement I have a coaxial cable with current density Jo in the center, with radius a, going in -z_hat direction. This generates a magnetic field. The outside of the cable, radius c, also carries a current density Jout going in the +z_hat direction. This generates its own magnetic...

Author: Steven Weinberg Title: The Quantum Theory of Fields Amazon Link: https://www.amazon.com/dp/052167056X/?tag=pfamazon01-20 Prerequisities: Contents:

Hello, this is my first post here, so hopefully I do this in the right way... Homework Statement A hollow spherical conductor carries a net charge of 21.5 μC. The radius of the inner hollow is 5.2 cm and thee full radius of the sphere is 7.8 cm. At the center of the sphere, in the...

Homework Statement Let F be an infinite field (that is, a field with an infinite number of elements) and let V be a nontrivial vector space over F. Prove that V contains infinitely many vectors. Homework Equations The axioms for fields and vector spaces. The Attempt at a Solution...

Coulomb's Law F = kqq/r^2 Why does the intensity of a uniform electric field not get weaker in the middle? I would understand this if the intensity over distance was a linear function, but it isn't. The force near one of the plates would approach infinity, because r^2 is so small... but in...

Homework Statement Having issues determining what I am doing wrong, so perhaps one of you can pin point it. I have the solution, and I am extremely close to the same result, however, I am nonetheless wrong. Find the conservative vector fields potential. \vec{F}(x, y, z)=[(2xy-z^2)...

In the Standard Model of particle physics are we to think of the electron(positron) field and the photon field as separate fields? Is it possible to think of the electron(positron) field and the photon field as just different "modes of vibration" of some more basic field? Can this line of...

Suppose I want to try and guess the fields of a short laser pulse. We know that fields that satisfy Maxwell's equations minimize the action E^2 - B^2 (say far from charge and current)? For a plane wave E^2 - B^2 = 0? Will a general solution of maxwell's equations satisfy E^2 - B^2 = 0...

Scientists can produce laser pulses of order one wavelength in "length" see, http://www.bbc.co.uk/news/science-environment-19489384 Do Maxwell's equations admit solutions of such short pulses? Can one approximate such a solution by multiplying a plane electromagnetic wave by the...

Hi all! I want to ask about vector fields. So if I had any kind of field for example \bar{F}(x,y) = (0,x) which represents a river or somthing similar and I put into the river a particle, or point-like body how can I get the path, or curve (flwo line?) from the vector field? I mean that path...

Can the products of high-energy particle collisions include the creation of electromagnetic/strong/weak/gravitational fields (whether transient or not) in parallel with or in lieu of other new particles? IH

I still have a long time to decide, but I am interested in the fields of particle physics, astrophysics, and cosmology. Here are my questions about them: 1. What field has the best outlook for the future? 2. Is there a degree that provides flexiblitiy in the choice? 3.What fields have the most...

Homework Statement Given some ElGamal private key, and an encrypted message, decrypt it. Homework Equations Public key (F_q, g, b) Private key a such that b=g^a Message m encrypted so that r=g^k, t=mb^k Decrypt: tr^-a = m The Attempt at a Solution My problem is finding r^-a...