Fields Definition and 1000 Threads

I'm going to ask a very general question where I just would want to hear different possible methods that can be thought of in this kind of problem. I am trying to solve a very specific problem with this but I won't talk about that because I don't want someone to give me the answer but ideas for...

Homework Statement Consider the charging capacitor in problem 7.34 (A fat wire, radius a, carries a constant current I, uniformly distributed over its cross section. A narrow gap of wire, of width w, w<<a, forms a parallel-plate capacitor) a) Find the electric and magnetic fields in the gap, as...

I like getting all knowledge and also like being an all rounder. I like Maths, physics and chemistry. I think in mechanical engineering only mechanics is taught. In which branch all topics are taught? Or can one choose various fields like elec engineering, chemical engineering, computer science...

a simple idea. Maxwell’s theory of magnetic fields says there is two components ,an electrical field and a magnetic field. (put simply). I have an idea to pick up radio waves using a magnetic beam. rather than the normal dipole set-up, just wondering if you think this idea is possible to make...

Homework Statement What is the magnitude of the magnetic field inside the solenoid at t = 1 ms? Homework Equations Not sure The Attempt at a Solution Well I would make an attempt but firstly I have a question. What I want to know is the above question simply referring to the emf of the...

Examine the charge distribution shown: b) What is the net electric field acting on charge 1? Attempt at the answer: E2 = Kq2/r2^2 = (9.0 x 10^9 Nm^2/C^2)(3.0 x 10^-5 C) / 2.0m^2 E2 = 6.75 x 10^4 N/C E2 = E3 ( therefore, same procedure) eNet = Sqr.rt. 6.75 x 10^4 N/C^2 + 6.75 x 10^4 N/C^2...

Homework Statement Homework Equations n/a The Attempt at a Solution I don't understand how the book went from calculating Green's theorem on ##\int _c Pdx + Qdy + \int _{-c'} Pdx + Qdy = ## (1 in the attached picture) to getting (labeled 2) ##\int _c Pdx + Qdy = \int _{c'} Pdx + Qdy ##...

Homework Statement Need someone to confirm if I answered correctly. Thanks for your support :) A) Draw the pattern of the gravitational flux passing through a horizontal surface A, of area 1m² close to the Earth's surface. B) What is meant by the phrase "Gravitational potential at a point in a...

Field of what exactly? Sounds is vibrations in air molecules. Electromagnetic waves are vibrations in fields of what? Where are these fields existing? Wiki states that fields are "A field is a physical quantity that has a value for each point in space and time." Where is the physical...

Wikipedia define EM field as "a physical field produced by electrically charged objects" But there are no electrically charged objects in between cosmic entities and yet Wiki states "The electromagnetic field extends indefinitely throughout space". What am I missing here?

Hi everyone. I'm an electronics eng. student, and, during my studies, and my life outside university, I've heard several times of how electromagnetic fields could affect our body, in a way or another. There are also various resources talking about how these fields can attack cancer...

I am meeting a professor this week to see if I can work in his lab. His area of research is magnetism. In a preliminary meeting, he told me that the 'ambient' magnetic field in the lab is about twice the magnetic field of the earth. I spent about 10 minutes in the lab. There was a machine with...

1. I have heard that if you take 4 batteries and 2 non-coated wires, and run the wires + to -, with current flowing in opposing directions, with the wires in close proximity, that a magnetic field will be created between the 2 wires. Is this true? 2. Since photons have no charge, is there...

So I'm trying to figure out the electric field that is acting on a point. This point is .3 m right of a point charge with -2N/C and .8m from a point charge with +4N/C. I've drawn it out, and realize both will have an impact on this object. what the issue I'm having is figuring out a formula to...

Homework Statement The below region of space shown has uniform electric and/or magnetic fields, dependent on the conditions listed for cases A-G. Identical positively charged particles enters these regions with the same velocity. Rank the magnitude of the force on the particle just after it...

Homework Statement [/B] Charged particles with equal mass and identical initial velocities move through regions of space that may have magnetic fields. Rank the magnetic field in each case from greatest to least. For this question, fields out of the page will have positive values, while fields...

Consider a moving neutron passing by an electromagnet, will a neutron be deflected? This video seem to show that the neutron would have to be charged in order for it to move

Hello everyone, I am a junior year EEE student ( in a South Asian country ) and I will have to declare my thesis topic pretty soon. Anyway, the reason I am here is that I love Physics and want to migrate to something that is more heavy on the theoritical side. Things like particle physics...

I have been studying quantum field theory and I am currently in the Lagrangian field theory chapter in my book. Now it says that the energy momentum tensor is as follows: Tμν= [∂L/∂(∂μφ) * ∂νφ] - δμνL Note: I am using L to symbolize Lagrangian density and not just Lagrangian since the latex...

Homework Statement Please refer to attachment for solution. Can you help with the following (please refer to attached). If I understand the problem, both magnetic fields B1 & B2 need to change direction, due to the change in current (I) by replacing the positive with a negative ion. Your...

Hi, I am trying to calculate the laplacian of a scalar field but I might actually need something else. So basically I am applying reaction diffusion on a 2d image. I am reading the neighbours, multiplying them with these weights and then add them. This works great. I don't know if what I am...

I was thinking about the connection between fields and particles. For instance the scalar field Φ(x) and the field Φ(x)+a both represent the same scalar particle. Because the action ∫∂Φ∂Φdx^4 is unaltered and the propagator <0|[Φ(x)+a,Φ(y)+a]|0> is presumably the same. What about if we replace...

Homework Statement A magnetic field of 1.4 T [N] is 4.0 m wide. A very long wire crosses the field. a) If the current in the wire is 2.0 A [W]. find the magnetic force on the wire. Create a diagram. b) What will happen to the force on the wire if... i. The wire is rotated slightly in the...

I want to preface this by saying the question is a little tongue in cheek, I don't personally think that pursuing fame and glory is a good reason at all to be pursuing a career in mathematics. However, I would like to know what people here feel are the sort of traits that mathematicians who...

Homework Statement A magnetic field of 0.0200 T [up] is created in a region. a) Find the initial magnetic force on an electron initially moving at 5.00 E+6 m/s [N] in the field. b) What is the radius of the circular path? c) Make a sketch showing the path of the electron. Electron Charge =...

Homework Statement [/B] Select the answers which complete the statements below (e.g., if answer A completes the first statement, and answer B the others, enter ABBBB). A) positive B) negative C) neutral D) cannot tell A positive point charge is brought near the outside surface of a...

Homework Statement Let ##T## be a ##(1, 1)## tensor field, ##\lambda## a covector field and ##X, Y## vector fields. We may define ##\nabla_X T## by requiring the ‘inner’ Leibniz rule, $$\nabla_X[T(\lambda, Y )] = (\nabla_XT)(\lambda, Y ) + T(\nabla_X \lambda, Y ) + T(\lambda, \nabla_X Y ) . $$...

Homework Statement The tine sphere at the end of the weightless thread has a mass of .60g. It is immersed in air and exposed to a horizontal electric field of strength 700 N/C. The ball is in equlibrium in the position shown. What are the magnitude adn sign of the charge on the ball? Homework...

My textbook is going through an example on splitting fields. It asked to find a splitting field for x^4 - 6x^2 - 7 over the rational numbers. This polynomial factors to (x^2 - 7)*(x^2+1) which has roots of 7^(1/2) and i. So i figured the extension field E we are looking for is Q(i)(7^(1/2)), but...

Homework Statement Let V be a vector space over the field F. The constant, a, is in F and vectors x, y in V. (a) Show that a(x - y) = ax - ay in V . (b) If ax = 0_V show that a = 0_F or x = 0_V . Homework Equations axiom 1: pv in V, if v in V and p in F. axiom 2: v + v' in V if v, v' in V...

I am reading about the Velo-Zwanziger problem in which particles with spin higher than 1 propagates faster than light when the particles are coupled with an electromagnetic field. In the original paper: G. Velo and D. Zwanziger, “Propagation And Quantization Of Rarita-Schwinger Waves In An...

Homework Statement Two charged particles (P & Q) are fired into a uniform magnetic field that is directed into the page. When a particle possessing charge q moved through a magnetic field B at a velocity v it experienced the lorentz force that has a magnitude of F=qvB. What is the sign of P...

I'm trying to re-derive a result in a paper that I'm struggling with. Here is the problem: I wish to calculate (\nabla \otimes \nabla) h where \nabla is defined as \nabla = \frac{\partial}{\partial r} \hat{\mathbf{r}}+ \frac{1}{r} \frac{\partial}{\partial \psi} \hat{\boldsymbol{\psi}} and...

Homework Statement An electron traveling horizontally east passes between two horizontal, oppositely charged plates and is deflected downward. Part A: Passing through the same space between the plates, in what direction (if any) a proton traveling horizontally east would be deflected? Part B...

What fields or branches of physics are most researched today? Which has the most unsolved mysteries?

I've been told that magnetic field does not mask or influence any GHz transmissions; TV, Radio, Wi-Fi, etc. and should not pose a problem. Can someone explain why they do not interact? Credible documentation such a law or theory? Educational documentation? Thanks in advance.

My question is simple; yet, I can not find the answer. In the picture below, all variables are identical; the plate separations, surface area, etc. The only difference is the fact that example 1 has 2 different dielectrics. Better yet, it has a dielectric that doesn't extend the entire distance...

Can anyone help with an ongoing argument we are having. When a particle interacts with a vector field e.g. the electric field, it experiences a force trying to move it which depends on the particle charge and the local field condition, - but when it interacts with a scalar field e.g. the Higs...

Based on what I have learned, I know that a theoretical physicist has to work in a specific field. But can one work in two? For instance, a person who has a PhD in cosmology but is working on both cosmology and field theories (quantum, unified). Or maybe even the same person working at a...

Homework Statement We are giving to lines: r1(t)=<1-t,4,5+2t> r2(s)=<2,1+s,-s> 1. Find an equation perpendicular to the two lines and passing point P(1,1,1) 2. Find Coordinates of points of intersection of the line found in #1 with planes x=-1, xz-plane 3. Parametrize the line segment joining...

I'm in high school, thinking about what I want to do in college. I am aiming to get some sort of PhD in Theoretical Physics. I would love to just get one in general theoretical physics, but I am unsure if that is offered. I know that I can go into specific areas such as particle or field...

Are a field and its complex conjugate independent? It seems like they're not, as one is the complex conjugate of the other, so if you have one, you know the other. However, it seems in path integrals, you integrate over the field and its conjugate, so they can take on values that are not the...

According to page 61 'Einstein' by Andrew Robinson an electric charge at rest produces no magnetic field. But: For an observer moving East with uniform motion the charge will appear to be moving West uniformly and B, using a sensitive compass, will detect a magnetic field around the 'moving'...

Homework Statement I'm reading Peskin and Schroeder to the best of my ability. Other than a few integration tricks that escaped me I made it through chapter 2 with no trouble, but the beginning of chapter three, "Lorentz Invariance in Wave Equations", has me stumped. They are going through a...

Entering my third year of my bachelor of science majoring in maths/physics and having some trouble deciding what courses to do this semester. I know for sure I will be taking complex analysis and 3rd year quantum however am having trouble picking between 3 in particular for my final two courses...

I should add context to this question that what I know so far of the emf is that it is defined as ##\mathscr E=\oint f \cdot d\ell## where ##f## is the sum of the forces on the charges. In the textbook I'm reading it gives an example of where a person pulls a rectangular wire with a velocity...

Why are electric and magnetic fields in an electromagnetic wave in phase? Can somebody please explain that?

Does anyone know of fields (with additional structure/properties) other than either ##\mathbb R, \mathbb C ## that are "naturally" manifolds? Thanks.

i am having some trouble with understanding the magnetic fields inside transformers and how they relate to back emf. In particular, I am considering the two cases of current passing through the primary coil but not the secondary coil, and then with the secondary coil as part of a complete...

I'm not quite following why Wick's Theorem only applies to free fields. What part of the argument depends on a free field assumption?