Electromagnetic waves Definition and 322 Threads

I know that in a vacuum, speed of light is constant. My question is more about the speed of light in a material like air. Dispersion of light in a prism tells us that the speed of light or the material index depends on the wavelength ( or frequency which is constant ) so I thought that air...

1. Statement: Prove that the EF and the MF are in phase far away from an oscillating electric dipole Homework Equations : The oscillatory motion equations for charges (q(t) = q_0sin(ωt) etc.)[/B] The Attempt at a Solution : Attached PDF file[/B]

I am confusing about it that what are electromagnetic field books said that it does not require medium then how they propagate in vacuum and we also know that waves are disturbance through a medium

Today, I made the following question at Physics SE, but the community redirected me here In short, I have made a proof for EF/MF phase difference near an oscilating dipole that "vanishes" far away from the dipole. So, what I am asking for is a proof verification. The physics SE post...

hey, i was wondering if this can be possible by human force, if so why are we not finding this?

How can I mathematically determine curvature for a satellite dish for a specific radio wavelength?

Homework Statement An em wave in free space has an electric field vector E = f(t-z/c0)x where x is a unit vector in the x direction and f(t)= exp(-t2/τ2)exp(j2πv0t). Describe the physical nature of this wave and determine an expression of the magnetic field vector. Homework Equations...

How are all of the above fields different from each other what makes them what they are?Any comments would be appreciated.

I don't know if this question should be in the quantum physics section, so I'm just posting it here. So I have doubts regarding matter wave and electromagnetic waves associated with electron or just any particle. 1. So I understand when an electron is accelerated, it produces electromagnetic...

Consider two adjacent people speaking in cell phones. Why the signals don't interfere with one another? Does each phone communicate with a distinct frequency? If so, how?

In texts on geometrical optics I have read that an image is formed where light rays converge -- without an explanation of why. Thus I ask, why are images formed where light rays converge? In particular, what is the answer to this question in terms of the wave theory of light (Electrodynamics)...

Hello, For reasons I’ve read here in this forum, some material (let’s say PVC or paper) are not transparent to light. But light is an electromagnetic wave. If I lower the frequency, that material is now transparent, even if I cannot detect it with my eyes but must use special equipments, the...

Homework Statement For an electromagnetic wave with an electric field given by \mathbf{B}=\mathbf{i} E_o cos (kz-\omega t)+ \mathbf{j} E_o sin (\omega t - kz) where Eo is a constant Find (a) its direction of propagation (b) the magnetic field (c) Poynting vector (d) energy density, i.e., the...

Maxwell's equations solutions in vacuum - is a free electromagnetics waves. Such solutions can be obtained even without knowing anything about the charges and currents. Does this mean that such waves is the essence , not related charges, e.g. free electromagnetic waves? Moreover, the Maxwell's...

I see the term o"ptical frequency" in some articles. From Wikipedia I read that it means the whole EM spectrum. But something says to me it may be only the visible part of the spectrum. Now, which definition is correct? Thanks

If light is a quantum object, then what are electromagnetic waves that Maxwell predicted?

Can someone please describe the diffraction orders on a nano-grating? I am reading articles about imaging devices, and I cannot understand the diffraction orders For example, incident wave can be mapped into a propagating wave through the -1, 0, and+1 diffraction orders. Is any of these...

I see this term a lot. What is the different between homogeneous and inhomogenous? What properties are different? Thanks

Hello! When considering the boundary conditions for the electromagnetic field \mathbf{E}, \mathbf{H} on the surface of a Perfect Eletric Conductor we have: \mathbf{E} \times \mathbf{\hat{n}} = 0 \mathbf{J}_S = \mathbf{\hat{n}} \times \mathbf{H} the tangential electric field should vahish...

Hello! In http://my.ece.ucsb.edu/York/Bobsclass/201C/Handouts/Chap1.pdf, pages 19-20, the Love's Theorem in Electromagnetism is declared. In presence of some electric sources \mathbf{J} and magnetic sources \mathbf{M} enclosed by an arbitrary geometrical surface S, which produce outside S a...

My textbooks says in a region where there is no charge or current Maxwell's equations read divergence of E=0 Curl of E=-dB/dt all d are partial Divergence of B=0 Curl of B=ue(dE/dt) I get the math of showing that there are waves, but I don't get some of these conditions. 1st don't you...

Hi! In classical electromagnetic theory the energy of an electromagnetic wave is proportional to its amplitude squared. In contrast, the quantum mechanical equation ##E = \hbar \nu## states that the energy is proportional to the frequency of the wave (photon). Now, according to the...

Hello all. I have been searching for information on wave beats in light but haven't been very succesful. I have found a lot of information on beats but most of it refers to sound or to waves in general without referring to EM waves. I think that when EM waves are dispersed at normal incidence...

Dear All, Can anyone explain me if light is an electromagnetic wave then why a charge does not experiences an electric force(or magnetic force) due to electric field component(or magnetic field component)of electromagnetic wave? this is a very challenging question asked by my friend to me...

Hi Everyone I am wondering about something. As everyone here knows, electromagnetic waves obviously possesses an electrical component and a magnetic component. Firstly, can electromagnetic waves be considered to be a sort of complex wavefunction? If yes then do the two components of...

So I can't find this anywhere, but I would really like an answer as it's driving me up a wall; Are the amplitudes of all electromagnetic waves the same, and if so how are the speeds of the particles that move along the wave not > c? Thanks in advance.

Hello everyone. I have a question about waves and how they interact in certain settings. 1.) What happens when two EM waves (of different frequencies and amplitudes) arrive at the same space at the same time, and are traveling 45 degrees to one another? Do their trajectories, amplitudes, and...

Capacitors are popular candidates for explaining electric fields. The phenomenon becomes really apparent with the aid of a leiden jar ...which is really just a capacitor. Anyways, as long as you're cranking the handle on the electrostatic machine, the charge is going to build and build until I...

The electromagnetic spectrum contains wavelengths that are on the scale of macroscopic objects. What I'm not sure about then is, does this mean that photons corresponding to these "macroscopic" wavelengths are actually that size? My guess is that these photons have a corresponding electric field...

Is it true that the energy in electromagnetic waves can only be released in "packets" of energy? Or is this only the case for a system where a standing wave change from one mode to another which results in sending out an electromagnetic wave (photon). In other words if I ride on my bike...

Does the law of the conservation of energy apply to the light in our universe? If yes, is our universe a closed system? If no, is our universe losing energy?

Hey guys. From my textbook, I understand that linear polarization occurs when the phase between components of an electric field wave (and thereby the magnetic field wave) are zero. Elliptical polarization occurs when the magnitude of the components comprising a field wave is not equal in...

Does the electron emit electromagnetic waves?

Can an electromagnetic wave be deflected by electric or magnetic field.

Hello everyone, My Name is Dwayne McIntosh. I am not that good at Physics or Mathematics however i do have a problem. I was brainstorming the other day and i wanted to know, what if one was to use say electromagnetic waves (may be different wavelength,frequency or Photon Energy, but with...

1. In an EM wave traveling west, the B field oscillates vertically and has a frequency of 88.8 kHz and an rms strength of 7.8 * 10^-9 T. Determine the frequency and rms strength of the electric field. What is its direction? The electric field of an electromagnetic wave is given by Ex=E0 cos(kz...

Hello everyone. I'm studying wireless communications at school, and I have a question... If frequency is the amount in time that something oscillates, in this case, electrons, wouldn't a higher hertz, mean faster data transfer? A 2.4 MHZ way is must slower than a 2.4 Ghz wave correct? So...

Homework Statement Homework Equations The Attempt at a Solution see last attachment I am not sure if I used the right equations or not.

I remember having great confusion when I first read about electromagnetic waves. I remember being introduced to a historical text about ether when I was a child, and thinking it was an unsolved puzzle. I'd never really been able to shake the question "What does an electromagnetic wave propagate...

Hello there. I have to do a calculation (problem 5 of chapter 12 in Wald) verifying the super-radiance of electromagnetic waves incident on Kerr black holes and have a few preliminary questions. As background: on pages 328-329 of Wald, there is a discussion of super-radiance achieved by Klein...

I am beginner in physics.I have question that when dc current flow they flow with apparent drift velocity so it appears that it should not emit em waves.But in actual current flow electrons are accelerated due to applied potential and also deaccelerated during collision so even they appear to...

I was reading about how a plane mirror reflects light and would like confirmation I have the right theory. It says that the metal coating of a mirror is a conductor in electrostatic equilibrium which means the electric field is zero. As the electromagnetic wave hits the mirror the electrons...

hi pf, i have been trying to understand since last few weeks how electromagnetic waves, say light travels? Not the way transverse waves do. It must require a medium. Then in vacuum how light travels? you may answer that with oscillating electric fields and magnetic fields at perpendicular to...

Do electromagnetic waves expand as they travel across the cosmos? e.g. Do the wavelengths of emitted light, from distant galaxies, have longer wavelengths when they reach Earth than they did when they were emitted?

I pay for chegg to help me with physics but sometimes I'm not quite sure if the site is right. Could you please tell me if I am doing the below problem correctly? My way is different than Chegg's so I would just like to make sure I am not wrong because I am getting different answer than that...

Applications: garage door openers: 40.0 , standard cordless phones: 40.0 to 50.0 , baby monitors: 49.0 , FM radio stations: 88.0 to 108 , cell phones: 800 to 900 , Global Positioning System: 1227 to 1575 , microwave ovens: 2450 , wireless Internet technology: 2.4 to 2.6 . Which of the...

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...

Hello, Is there any difference between 50/60 AC current and a 50/60 Hz photon stream/electromagnetic wave propagating through a medium ?? Regards, Hex

We can determine what kind of elements exist in different planets by observing electromagnetic waves from planets' direction, but does anyone have any suggestion on how planets generate electromagnetic waves at the first place? Does anyone have any suggestions? Thanks in advance for any...

Yer.. I'm lazy and tired, did not enough research and found out that the radio/electromagnetic wave makes all the electrons move back and forth when the wave oscillates between the magnetic and electric fields... so you can see how much the current oscillates etc. But... um cameras work...