Faraday Definition and 213 Threads

Hi, How do you calculate the current from a faraday disc? I have found calculations for the voltage, but what about the current? I think it is a bit more complicated due to back emf, but if you know what motor you are using (the torque it can generate), then can you work it out? Thanks for any...

Dear all, In textbooks about optics in magneto-optic materials, we often come across a Hermitian permittivity tensor with off-diagonal imaginary components. These components are relevant to the Faraday rotation of plane of polarization of light through the material. Now my question is: Is the...

Hello everyone , as for starters I would like to ask two questions. As I've been reading about the homopolar generator I have the basic understanding of all the workings yet here are my questions. Since the rotatig disc produces a current within while rotating in an axial magnetic field...

I'm trying to calculate the Faraday 2-form with two vectors as an input. The problem is I don't know how to interpret my results. The Faraday 2-form is given by, F=1/2Fαβdxα∧dxβ And I'm told to calculate F(u,v) where u=uαdα and v=vαdα I expanded out Fαβ with the determinant given by the wedge...

The Faraday paradox is a hard one to get ones head around and I was wondering if there is a similar scenario, involving an E field where there is / or is not an induced emf?

Suppose there is an uniform magnetic field along z-direction. Now someone turns off the field. Then there will be an induced electric field. Can anybody draw this induced electric field lines? I know the electric field will curl around. But where will be the centre of that curl. Do the electric...

Electrodynamics (Lorentz Force & Voltage) [edited] Two part inquiry PART I Situation: I have a B-field and I'm pulling a straight piece of wire through that B-field You pull the wire perpendicularly through the B-field at velocity v; charges between points a and b will...

Hi guys, so we currently ran an experiment where we calculated the verdet constant when laser light passed through a glass rod then through an analyzer to a photodetector. The experiment worked great for us but I wanted to know if anyone has ever calculated the verdet constant for any other...

Hello everyone. I am trying to use a Faraday cup constructed by myself to measure the electrostatic charge presence in particles of a fluidized bed reactor. I am trying to test if it works properly but I am having some problems. I am tried to apply a voltage of 1.5 V till I obtain that...

The faraday constant is prayed: $$\\ 1\; \text{F} = \frac{96 500\;\text{C}}{1\;\text{mol}}$$ (approximately...) I'm wrong if I say that the faraday constant is: $$\\ 1\; \text{F} = \frac{96 500\;\text{C}}{1\;\text{mol e}}$$ ?

if I build a faraday cage just to protect device from lightning or other electrostatic source (not electromagnetic pulse), and I need that as light as possible... I will build it using a mesh to make it light.. now, how large the mesh' holes is allowed ? is there any calculation for this...

Although it is usually stated and taught that Maxwell developed pretty faithfully Faraday's views and experimental work into a mathematically solid theory, it is probably not widely known this is actually only partially correct, as Maxwell in fact changed much of Faraday's original theoretical...

The purpose of the lab was to measure, and also calculate, the induced current in a disconnected coil, due to a second coil connected to a power supply. Involved magnetic fields and electric fields (I think. For the purposes of this lab, the magnetic permittivity is 1.26*10-6, the number...

Hi all I'm trying to replicate the effect of a 45° Faraday rotator using a series of waveplates instead. I've encountered some difficulties using the jones matrix notation, due to the differencies of the matrix formulas between the books I'm referring to. The main book I'm using is...

Hi guys, The other day I found myself asking the question below and couldn't quite manage to re-align my own personal experience with E&M theory. I am sure it will just be a gap in my knowledge base of E&M. The Question: If you are contained within a metal mesh cage which acts as a...

Hello! Talking about propagation of an electro-magnetic field in a non-isotropic medium, I've got some troubles with the expression in object, used to show the Faraday rotation of the polarization of a field. Homework Statement An electro-magnetic field enters a particular medium...

Homework Statement Why does the Faraday Law of Induction not suffer from the inconsistency encountered with the Ampere Law? Homework Equations \oint E * dl = - (N) d/dt \intB * dA The Attempt at a Solution The Ampere Law is inconsistent with the time varying equation of...

Help understanding Faraday cages... I have a basic understanding of electrostatics but can't quite get my head around how a Faraday cage works. If you take a hollow metal sphere for example and bring an external source charge towards the sphere why is there no electric field on the inside of...

Hi, I am confusing if capillary-gravity waves (Faraday waves) belong to a type of acoustic waves stricto sensu? What's the difference between Faraday standing waves and acoustic standing waves (interference) at the the air-liquid interface. Thanks harmonyU

Hi ,imagine a situation , we have a large tesla coil, a faraday cage , a man in it and he cage is grounded. Now we switch on the coil high frequency high voltage currents makes a breakdown of air and produces a path so that the current goes and strikes the cage.Now according to faradays law the...

Homework Statement Describe the Faraday effect as it might be observed in a glass cell contained within a solenoid Homework Equations The Attempt at a Solution When a glass cell is immersed in a strong magnetic field, the plane of vibration of light waves is rotated. When...

Homework Statement I'm asked to start from Faradays Law & Ampere-Maxwell law then derive the equation for the magnetic field, B, in the form; del2B = 1/c2 * d2B/dt2 Homework Equations Faraday: curl E = -dB/dt A.M : curl B = ε0μ0 dE/dt The Attempt at a Solution taking curl of...

Hi guys, I know Faraday effect is the rotation of the plane polarization of light when the light passes through a transparent medium and a magnetic field is applied in the direction of the propagation. What actually causes it at the quantum level? Is it Zeeman effect or something similar...

Is there a force in this case: For the sake of simplicity, a spherical Faraday cage. A smaller charged sphere inside. If we move the small sphere close to the wall of the cage, will there be a force of attraction between the wall of the cage and the small charged sphere?

Hi! I have a question regarding the Faraday cage. I know how a Faraday cage works and understand the principles that make it work and why (potential difference, flux, gauss' theorem...) but I have a question. Why some Faraday cages work eventhough they have holes in their surface. For...

HI Assume we have a point charge in the center of a shell, now the inside inner wall will get an opposite charge and the outer side of the shell will have the same charge as the point charge. Since we have a charge on the out side, how isn't there any fields outside ?? how are we...

I was wondering how protective a Faraday Cage actually is, can it be overcome by sending more amperage onto the exterior or does that not matter? Also what would cause a Faraday cage to be ineffective, like would a cord powering the device inside render the cage useless? Thanks for your help!

Hi, I am a biologist and I do a lot of experiments on cellular electrophysiology. I keep my preamplifier and the biological subject inside a Faraday cage, and it works well. In some experiments I need to deliver a drug to the cell so I have to enter the cage briefly, with my hand only, and...

So I tried out a small, fun experiment of putting my cell phone in the microwave (not turning it on, of course) to see if the WIFI Hotspot capabilities were hindered by the Faraday cage that insulates the microwaves. I had heard that microwave cages will hinder If not completely block 802.11...

Hi, A parallel plate capacitor is charged from fixed voltage, after I cut voltage source. Now, what's happened if I place a Faraday cage inside capacitor (without touch capacitor) ? Capacity changed ? So energy of capacitor changed ?

I was looking for a mathematical explanation of a Faraday cage. In particular I was seeking something that relates hole size to the reflected and transmitted waves, using electromagnetic theory. This might also relate to a wire grid polarizer. Would anyone be able to help me?

Hello learned Engineers, Physicists, and people more useful than myself: Thank you in advance for reading. I would like to submit a more educated proposal to a utility company for a method that would allow it to install 500 kilovolt renewable power transmission lines through many residential...

what does calibrating a faraday cup mean??

A bar-shaped magnet is released along the axis of a long tube of copper. Describe the motion of the magnet and the energy exchanges involved. Neglect air resistance.

A changing magnetic field induces a field, G: ∇×G = -∂B/∂t (1) Now my book then says, since ∇×G≠0 while ∇×E=0 and ∇\cdotG=0 while ∇\cdotE ≠0 we might as well see G and E as the same field, and thus see G as an induced electric field. I can understand that, I just don't understand how one...

I am sick of searching and being confused more and more specially about lenz law... THere are many demonstrations and many law.. Can someone list atleast the most important one...

The most difficult aspect of hydrogen fusion is overcoming the electrostatic forces that cause the hydrogen nuclei to repel each other. Would it be possible to place one of the nuclei inside some conducting sphere like a Buckminsterfullerene so that the fullerene acts as a Faraday cage? The...

I'm curious about what are the similarities and differences in GR between the EM field (Faraday) tensor, a 2-form and therefore antisymmetric tensor that describes the force of the EM field in the relativistic formuation of EM, and the EM field stress-energy tensor, the part of the SET that...

This may be a stupid question, but nonetheless it is confusing me (maybe I am stupid :p) The equation states that there is an induced emf in a loop when there is a change in magnetic flux through that loop. Or V = -d\phi/dt Though how does it work when you have self induction and induction...

1. Good day, Using 4-inch pole caps and a Mettler M5 balance, I got all the values required in order to calculate the magnetic susceptibility of several inorganic compounds such as Manganese (IV) oxide (MnO2). I have the change in mass of the tube with the sample of the compound when the...

[b]1.I must make a Faraday cage with copper mesh that will protect product from stray 400 MHZ signals.The operator wants to see his product inside of the cage so i want to use the coarsest mesh I can for visibility reasons.I still need good protection from 400mhz.What is the coarsest copper mesh...

Dear Sir and Mam, So recently, I have been doing an experiment with Faraday waves. I feel like there are some critical things I don't understand about fluid dynamics (they don't offer it as a course where I go to school), so I was wondering if anyone on pf was good with fluid dynamics...

Hi, I am an engineering student, and I have an idea for a project, but I am not sure if it is viable. I want to make an article of clothing such as a jacket with several mini faraday flashlight-esque devices inside. They would be connected, and would charge a cell phone or other electronic...

Hello there, is there any computer software or programs out there that you can create various Faraday cages simulations

Homework Statement I want to run a magnetic liquid past a coil to product a current. In a vertical tube I want to inject an air bubble to push the liquid upwards. Of.course the air escapes the top and the liquid re-cycles. - Like a variant of Faraday's Generator with moving liquid magnet...

Hoi! I was wondering about the Faraday cage. When lightning strikes a car, the driver is not hurt since he/she is sitting in a Faraday cage. The charges cancel out and the net E field in the car is zero, though the potential inside the car should reach whatever is on the outside, meaning...

Hi everyone, I have recently built a Faraday Cage. However it seems to be working in reverse and amplifying the noise! My test setup: I place a 3.3 Mohm Bulk metal precision resistor across the terminals of the meter and measure the pk-to-pk noise using the meter. I now place the meter...

Hi everyone! I am a high school student and my final project is to create my own Faraday Flashlight. I used the following website to find out what materials I needed: http://www.shake-flashlights.com/how-they-work.html After having bought all the supplies, coiling the wire manyyy times around a...

It is for my university course but I didn't find it worthy of the advanced physics section. Homework Statement A circular metallic disk of radius b rotates about an axis perpendicular to its centre with an angular velocity ω in a constant magnetic field, strength B, which lies in the same...

Can a faraday cage be used to stop the radiation at the Japanese reactor? If not why not? I know the frequencty is high but what if you pulsed DC current at the same frequency would that stop it?