Electromagnetic waves Definition and 322 Threads

Homework Statement A radio-frequency EM plane wave propagates in the +z-direction. A student finds that her portable radio obtains the best reception of the wave when the antenna is parallel to the x--y plane making an angle of 60 degrees with respect to the y-axis . (a) Consider an instant...

Electromagnetic waves!Conceptual help please! A long steel wire is cut in half is connected to a different terminal of a light bulb. An electromagnetic(EM) plane wave (E(x,y,z,t)=Esin(kx-wt)[y hat direction], B(x,y,z,t)=Bsin(kx-wt)[z hat direction]) moves past the wire. a) Suppose the wire...

I have three points: 1. According to wave-particle duality, even regular matter can be classified as a wave instead of a particle, for example, an electron or a neutron. My question is, what is this a wave of? A photon is a wave of oscillating electric and magnetic fields. Are electrons, say...

When a current is accelerated through a wire, an electromagnetic wave is created. What determines the frequency of this wave? Is it possible (theoretically and experimentally) to achieve the frequency of light? (Possibly with a large voltage from multiple capacitors and a super-conducting material?)

I am having some trouble understanding the concept of electromagnetic waves, I suppose because I expect them to be analogous to physical waves you can see or touch (such as on a string). Yes, I know one can actually see them at visible wavelengths, but that doesn't help because I don't...

Hi all, Can someone please elaborate on some of the following ideas so that I can get these down correctly? 1. is an electromagnetic wave a form of a self-perpetual motion machine? 2. since electric and magnetic fields contain energy, is this the hope that people (Tesla!) have for...

[b]1. The problem statement, all variables and given/known Is it true that nothing can travel faster than the speed of light? Can't all electromagnetic waves travel at light speed. Also, if the speed of light is a constant, is the speed of the other electromagnetic waves a constant such as x...

Homework Statement Write down the (real) electric and magnetic field for a monochromatic plane wave of amplitude E0, frequency ω, and phase angle zero that is (a) Travelling in the negative x direction and polarized in the z direction; (b) Travelling in the direction from the origin to...

How do electromagnetic waves travel in space? I understand these types of waves are different than sound waves where matter acts as a medium. But how do these waves travel in space where there appears to be no medium? Is the space time continuum actually a physical substance although far...

Why is it that electromagnetic waves, made up of constantly changing electric and magnetic fields are neither affected by electric or magnetic fields?...

Homework Statement An industrial laser is used to burn a hole through a piece of metal. The average density of the light is S = 1.24E9 W/m2. What is the rms value of each of the following fields in the electromagnetic wave emitted by the laser? Homework Equations S = ceoE2 S = (c/uo)B2...

How does, for example, the field of a single point charge arise as the solution of a wave equation? I tried solving the wave equation that arises from Maxwell's equations with a source, that is rho = q delta(0) (I can't get Latex to work), but it got too complicated for me. I think it might be...

I've already figured that oscillating charges produce electromagnetic waves...but if the charge was simply in translational motion through space, would that produce EM waves?

For an electromagnetic wave, why is the electric field in phase with the magnetic field? As one increases in a given positive direction, so does the other (also in a given positive direction). I was somewhat expecting them to be slightly out of phase for some reason. If its not too much to...

Hi all, I still can't fully understand why electrons only drift in a copper wire DC circuit. The basic explanation I've been given is that electromagnetic waves carry the energy and move at roughly half the speed of light in copper, while individual electrons only drift along as the medium...

Sup guys, What is an electromagnetic wave? Now i understand that its made of oscillating electric and magnectic fields perpendicular to each other, and is created when a charge is accelerated. But I am having trouble imagining it, when a charge is accelerated, how would it produce the wave...

What happens to the amplitude of an electromagnetic wave when it crosss from a less dense to a more dense medium? I couldn't find it anywhere on the net.

Suppose some astronauts have landed on Jupiter. (a) When Jupiter and Earth are on the same side of the Sun and as close as they can be to one another, how long does it take for radio transmissions to travel one way between the two planets? Suppose the astronauts ask a question of...

What are electromagnetic waves supposed to look like in 3D? Also, in the vacuum of space, electromagnetic waves are supposed to travel at light speed. Is this the linear speed? Or the speed of the flux as it curves?

The problem i have with understanding waves is that people just start drawing graphs of the sine function or some equally appaling function that oogles me over. The problem with this is that people begin to correlate a graph as such the Electric field to be something spatial. They assume that...

I Read That Einstein Began Searching For An Explanation Of Gravity In The Em Waves... I'm Not Aware That This Has Been Proven To Be Wrong. I Only See That Em Has Been Related To The Weak Force.. Can Gravity Be Only After Em Waves Exist Or Does Gravity Exist At And Within The Weak And Strong...

"Show that spherical dust grains within the Solar System which have a radius less than a critical radius r will be repelled by the sun, whilst those with a radius greater than r will be attracted towards it. Calculate r given that the mass of the sun is 2x10^30kg, its luminosity is 4x10^26W and...

Hello everyone, First and foremost I would like to see if everyone's having a good day? (assuming you respond yes) Awsome! Secondly I was hoping someone would be able to help me understand how dielectrics work. I don't need to know everything about dielectrics. I only need to know how...

How does antenna transmits electromagnetic waves? For example radio antenna. How does the antenna produces moving electromagnetic waves?

At school (a long time ago that is) we were taught: 1. a stationary charge produces a static electric field. 2. a moving charge produces a magnetic field, plus an electric field that is slightly different from the original electric field of the stationary charge. 3. a periodically...

Homework Statement A circular loop of wire can be used as a radio antenna. If an antenna with a diameter of 20.0 cm is located a distance of 2.40 km away from a from a source with a total power of 45.0 kW at a frequency of 101 MHz, what is the maximum emf induced in the loop? (Assume that the...

A speeder is pulling directly away and increasing his distance from a police car that is moving at 23 m/s with respect to the ground. The radar gun in the police car emits an electromagnetic wave with a frequency of 6.0 109 Hz. The wave reflects from the speeder's car and returns to the police...

What do electromagnetic waves look like in 3 dimensions? In my textbooks etc. they are always represented as the standard sine wave. But what about actual 3 dimensions? Are there waves with smaller wavelengths than gamma waves?

I'm having trouble with electromagnetic waves, perhaps just a vector calculus issue. I'd much appreciate some help in idenfiying it. If given say an example in an assignment of an electromagnetic wave: E = E_0 cos (omega(sqrt(sigma.mu) z - t )) X + E_0 sin...

Homework Statement I have to re-write the following statement because it is either incomplete or false. When an electromagnetic waves passes from one material into another with a higher index of refraction, its frequency will increase. Homework Equations N/A The Attempt at a Solution...

Homework Statement I've been trying to do this problem for about 2 hours now. I can't seem to find the right equations to use. Any help would be appreciated A spacewalking astronaut servicing an orbiting space telescope has run out of fuel for her jet pack and is floating 20.0 m from the...

Hi Guys, I was hoping someone could explain why commercial satellite uplinks (like those used in TV broadcast) are able to achieve such high bandwidth rates vs. radio uplinks like HAM OSCAR uplinks. I don’t completely understand how digital modulation is done onto radio wave, but at 1st...

Homework Statement Find the electric and magnetic field amplitudes in an electromagnetic wave that has an average energy density of 3.0 J/m3. Homework Equations u=1/2 eo E^2 + 1/(2uo) B^2 u=eo E^2 u=B^2 /uo The Attempt at a Solution I tried using these equations, but I wasn't...

Homework Statement Hello everyone, I have one more problem left of my homework and I seemed to be stumped. I don't even know where to begin with this problem, which comes from the section of my book labeled Single-Slit Diffraction. Anyways, here is how the problem reads: Problem 22.18...

I have an a-level exam tomorrow which is really important in deciding whether I can get into uni or not. So basically I am having a panic moment. Could you PLEASE tell me how you polarize electro-magnetic waves? What is the effect of polarization? Why do we polarize waves? How can you tell if a...

Homework Statement 1. Tune the Antenna Consider an AM radio station broadcasting at the frequency 1500 kHz, and wavelength 200 m.. Suppose the station has two antennas separated by 80m, one north of the other. a) (2 pts.) If the two antennas broadcast their signals in phase with each...

Energy Carried by Electromagnetic Waves- why is it wrong? Hi! I have this homework problem that I just don't understand why it's wrong. A monochromatic light source emits 110 W of electromagnetic power uniformly in all directions. (a) Calculate the average...

An electromagnatic wave is traveling in vacuum with frequency 5.7 x 1014 Hz. The wave has average total energy density of 4.6 x 10-6 J/m3. (e) How much energy does a 1.9 m2 flat surface (perpendicular to the wave propagation direction) receive in 9 s? E = 23598 J, how do i get that...

Light which are electromagnetic waves have an electric field component and magnetic field component. The electric field can be phase shifted but the magnetic field never does. In geometric optics, light is modeled as a straight line and its rules upon reflection and refraction are according...

I know that electromagentic waves do not need any type of medium, but why wouldn't it be possible for dak matter to act as a medium for waves such as light?

I had a question. I did a problem where a distant galaxy emitted light that had a wavelength of A. On earth, the light had a wavelength of B. B ended up being greater than A. The question asked if the galaxy was receding from the Earth or approaching the earth. The answer turned out to be the...

what is one advantage of transferring energy by electromagnetic waves?

Hi i am trying to understand how long a electromagnetic wave can travel... What is the attenuation that the electromagnetic wave face in the atmosphere... This question arised when i have read that marconni at the beginning of 20th century has sent electromagnetic waves from england to canadA...

I have about Maxwell's equations and electromagnetic waves. I'm looking for experiments related to this subject. I only found this (Hertz' experiment), http://www.juliantrubin.com/bigten/hertzexperiment.html But that is not detailed enough, my (high school/secondary school) teacher says, that...

Hi I am having trouble relating power to the electric field amplitude, I know that P=IA and E=cB, could someone please help? The problem reads: What electric-field amplitude is required to transmit an amount of power equal to that handled by modern transmission lines (that carry voltages and...

A 200 MW laser pulse is focused with a lens to a diameter of 2.0 micrometers. Part A: What is the laser beam's electric field amplitude at the focal point? Part B: What is the ratio of this electric field to the electric field that keeps the electron bound to the proton of a hydrogen...

I have a problem that I cannot get the correct answer. An Astronomer observes electromagnetic waves emmitted by oxygen atoms in a distant galaxy that have a frequency of 5.71 *10^14 Hz. On earth, oxygen atoms emit waves that have a freq. of 5.841 *10^14. What is the relative velocity of the...

A plane electromagnetic wave is incident from a higher index medium on a lower index medium at an angle that is greater than the critical angle. a) For the case of s polarized electric field, obtain an expression for the complex transmitted electric field vector, (E). b) For the case of s...

Hi, Can someone help me on the following problem: Suppose you are located 180 m from a radio transmitter. How many wavelengths are you from the transmitter if the station calls itself 1147 AM? (The AM band frequencies are in kilohertz.) I have used the following equation to find the...

I just need a little direction to get started on this problem. A magnetic dipole is uded to detect an electromagnetic wave. The antenna is a coil of 50 turns with radius 5.0 cm. The EM wave has frequency 870 kHz, electric field amplitude 0.50 V/m, and magnetic field amplitude 1.7 x 10^-9...