Electromagnetic field Definition and 222 Threads

Can a medium tension electromagnetic field cause permanent damage to LCD tvs? I am about to buy a LCD to my living room, but the builder said that, because of the electric cables in the wall having medium tension, it could cause an electric field that can ruin a LCD screen. Is this true...

As the title suggest, does this PEMF therapy crackpottery? I have been browsing the FDA website, and from what i read, manufactures do seem to provide adequate evidence to show that PEMF does help bone growth such as fractures and such. But do PEMF help will pain relieve, that i am not that...

Inspired by another https://www.physicsforums.com/showthread.php?t=176823", where the discussion drifts toward the (Schroedinger) wave function of photons, I rather like to focus on the electromagnetic (EM) field and its relation to photon(s): What actually is the relation between an EM field...

I will be very happy if you answer me. I tried several times on google to search about this but I didn't find anything. So please answer me, if you know the answer. Thank you.

An photon has mass zero by virtue of its momentum canceling its energy in m^2c^4 = E^2-p^2c^2 But in electromagnetism a field configution only has momentum when both a magnetic field and an electric field are present, e.g. in an electromagnetic wave. Now when there is only an electric or...

Homework Statement A 1400 nF capacitor with circular parallel plates 1.0 cm in diameter is accumulating charge at the rate of 25.0 mC/s at some instant in time. What will be the magnitude of the induced magnetic field 9.0 cm radially outward from the center of the plates...

Homework Statement Trying to magnetize water in a test tube so that it will move or pick up iron shaving(s) Homework Equations none The Attempt at a Solution Wrapped test tube with magnetic wire (500 turns) wire is connected to DC current of 122 volts. It will pick up iron...

I have created an external electromagnetic field by using DC current connected to magnetic wire that is wrapped around a small test tube. I put water in the test tube. I have increased/decreased the gauge of the wire, increased the volts of the DC current, tried AC current and I still cannot...

A while ago someone asked on s.p.relativity how a black hole can accelerate in a gravitational field, given that the round trip time to the event horizon is infinite. This seems easy enough to understand -- given that there's no background metric, what else could it do? But I realized that I...

Hello, What is the precise form of the electromagnetic field generated by a single charge q at a given point P and time t1, if the movement of q is described by M(t). I have seek the precise answer to this question in many books of physic, without success. I think it must be relativistic...

A charges cork ball of mass 1.00g is suspended on a light string in the presence of a uniform electric field has an x compenent of 3.00 x 10^5 N/C and a y component of 5.00 x 10^5 N/C, the ball is in equilibrium at \theta = 37 degree. Find: (a) the charge on the ball (b) thetension in he...

Greetings, I am currently working on an interesting experiment on crystalized metal and I need to find a way to get a detailed map of an electromagnetic field when current is induced into a metal sample. I found the basic 2D approach of using conductivity paper and Ag ink to be useless as it...

I have a problem understanding the meaning of magnetic field strength, denotet H. I have the following example from a textbook: 1. The path of magnetic field strength developed in a conductor loop is given by the formula H = (I*N*R^2) / (2*sqrt(R^2+x^2)^3) I = current N=number of turns...

This is an experiment which might prove interesting. We know , thanks to the work of Oersted and Ampere , that the field around a wire carrying a current and the field around a permanent magnet are identical. Both of these fields are caused by moving charges , although the field around a wire is...

Hello, i had a question (as many do on these forums, it appears ;). I know E_{k}=F_{0k} I also know B_{k}=(1/2)*(\epsilon_{klm}*F_{lm}) EM field tensor F^{uv} defined as: (I put tildes (~) into make it more like a matrix form) 0~~~~E_x~~~E_y~~~E_z -E_x~~~0~~~~-B_z~~B_y...

Consider the electromagnetic field in a linear medium with material properties \epsilon \ \ \text{and} \ \ \mu . Calculate \nabla \cdot \mathbf{S} for the energy flux \mathbf{S = E \times H} . My work: \nabla \cdot \mathbf{S} = \nabla \cdot \frac{1}{\mu}(\mathbf{E \times B }) =...

Why is it that as a particle propagates through an electromagnetic field, the electric and magnetic forces are perpendicular to each other? (through the straight line of the particles motion) What effect does this have on the particle's motion, wavelenght and frequency? Thanks

The QED Lagrangian is given by \mathcal{L}_{\hbox{QED}} = \bar{\psi}(i\partial - m)\psi - \frac{1}{4}(F_{\mu\nu})^2 - e\bar{\psi}\gamma^\mu\psi A_\mu What is the purpose of the middle term. I know that it represents the energy of the E and B fields. However is that due to the external...

For question 3, i don't know ho to differentiate the electromagnetic field. Can someone help me?

Is the electromagnetic field "real"? This is sort of a mix of classical and quantum so I put it here ... In our current view of the universe, is the electromagnetic field "real", or is it simply a manifestation of the true underlying causes behind the electromagnetic force? It seems to me...

hi, electromagnetic radiation is a combination of oscillating electric and magnetic fields...if a transmiter sends a cmplex elctro magnetic signal into space and then shuts down, there is no longer a source of information to the signal, how does this oscillating electromagnetic field keep its...

can't an electro-magnetic field be used to separate two liquids? For example: petrol and water(as they have different magnetic properties) i'd be grateful if someone helps me with this.