Radio waves Definition and 127 Threads

That is probably a badly worded question but I understand electrostatics and I want to send simple but efficient radio signals. If I switch on a strong charge in one place it'll effect a charge away from it depending on "Coulomb's law". How is this equation expanded to explain more efficient...

Homework Statement A radio telescope, whose two antennas are separated by 55 m, is designed to receive 3.0-MHz radio waves produced by astronomical objects. The received radio waves create 3.0-MHz electronic signals in the telescope's left and right antennas. These signals then travel by...

Hi guys I am struggling on this question and was wondering if anyone could steer me into the right direction with it Q: Radio X transmits on wavelength 2000m at a frequency of 100kHz. Radio Y transmits at a frequency of 1.5MHz. Calculate the velocity of the radio waves. So for radio X I used...

Suppose I have a transmitter and receiver and my friend in the next room also has it. Can we both talk with each other with radio waves as we do in cell phone. I know we can't talk if he is several miles apart. But if he is just in the next room, can we communicate?

dear sir i want to know what happens in certain stars that helps it give out radio wave we detect by radio telescope. can we compare with inductor in electronic circuit?

I would like to know if a a inductively coupled power transfer system also emits electromagnetiv waves. The system contains of two inductance coils one generating the magnetic field with AC, the other picking up the magnetic energy and transforms it into an AC, also. The current frequency is...

Hi, Reading through an Introductory Mechanics Textbook, I don't understand a part of an example on Nonuniform Acceleration - The effect of a Radio Wave on an Ionosphere Electron. I've attached the link. Can someone please explain how: a0 = (-eE0/m)sinωt By my reasoning, since...

Homework Statement Homework Equations w = 1 / sqrt(LC) The Attempt at a Solution hi there, I 1. I decided to choose, 93.3 MHz so 93.3 x 10^6 Hz is my freq. 2. I googled how a band pass filter diagram should look like and I found this, is the only way to create a low...

What is the advantage of high frequency radio waves over low frequency radio waves? E.g. Wi-Fi 2.4 GHz over FM radio ~100 MHz.

Hi all, so iv'e been looking around and can't find an answer to a question i have. I have read articles on wikipedia and understand the "basics", but i still cannot fully visualize the concept. Question: Do all frequencies on the em spectrum emit the same particles? i know that visible "light"...

I'm doing a study that involves radio waves passing through organic matter and have come across several sources that state that radio waves may heat organic matter when passing through it (For example: http://www.mobilfunkstudien.org/downloads/peleg_wm_10.5923.j.biophysics.20120201.01.pdf)...

What happens when radio waves of around 1900mhz (cell phone) is confined in an aluminum box. Will the waves be able to pass through the box to the outside. What would be the best way to get the waves to the outside of the box with only modifying the box. If i cut a hole would that improve how...

Homework Statement Parabolic radio telescope. Dish is fixed and across its centre a cable is suspended carrying a beam on which equipment is mounted to pick up radio waves. Basically it's just a parabola on the cartesian plane. How would you adjust the parabola ( focus, directrix, vertex etc...

Homework Statement Homework Equations The Attempt at a Solution The path difference between the two rays being received by antenna is ##h/cos(\alpha)## but how to relate the path difference with the intensity?

Hi, I am not a physicists and have been trying to understand some basic concepts about electromagnetic waves in the context of telecommunications. Now, this is what I know so far: the energy of electromagnetic waves is proportional to it's frequency (E = h*f), and basically it's the energy...

Hi there. I have a (hopefully) quick question here. FM radio stations transmit their information by manipulating the frequency of radio waves, but each radio station is assigned to a specific frequency. If the frequency broadcasted by a radio station is constantly changing (to transmit info)...

I'm interested in how to understand exactly how radio waves will propagate in a particular situation. I know that they are absorbed by metal and water, pass through other materials albeit with loss of power, and reflect or bounce off of surfaces as well. How do I know whether a radio wave will...

I would like to know about radio waves used for FM or AM radio. I have read many articles that say, "The sound is encoded and rides on a carrier radio wave". How is that encoded? I am under the assumption that waves just have a frequency and wavelength and that is all. If a wave is transmitted...

"At what minimal height must be situated the point of reflection of a radio wave emitted in Montreal and received in Paris? The distance which separates both cities is 5 400 km and the radius of the Earth is 6 400 km." I don't even know where to start, we didn't learn this. I would assume the...

Hi all Sorry if this is quite a basic concept, but I am confused about RF signals. The way I currently understand it is that radio waves in space are an oscillating electric and magnetic field at 90 degrees to each other traveling through a medium. However, when you pass a radio wave into a...

I wondered if people could clear up some misconceptions I have about radio waves. 1) If I have a 800 MHz wave, does this mean 800 Mbits per second can be transferred in theory? Could I not change the amplitude of this wave every 0.00000000125 of a second, So when a receiver is reading it...

How can you make radio waves? Explain it scientifically

Hi: I'm new in this site I need help here please I need a circuit that works as : 1- transmitter uses radio waves or any type of waves 2- sends waves for long way more than 3 km 3- consist of simple component than can be found in old electronic instruments such as old TV or radio...

I realize this might be a complicated question, but I can't seem to find any textbooks or papers that address this head on. Perhaps I am naive in this field. What happens to the electric and magnetic parts of a radio wave as it passes through the human body? As far as I understand: The...

I was reading somewhere that radio waves can actually light up gasses in these tubes. How does this work?

Would radio waves emitted by an antenna be considered Bremsstrahlung radiation caused by pushing the electrons back and forth?

How do radio waves carry the information? I mean the information is digital: 1 or 0, but what is 1 and what is 0 from perspective of radio waves?

I've read that ionosphere mirrors the short radio waves (25-30 MHz). So 2 questions: Why this happens? There is material on the internet, but it's rather complicated for me so far, I've just started to study physics. So I'd appreciate if someone explains this in more or less simple way. Why...

I don't think I have to write out the problem but let me know. There are two radio antennas emitting radio waves and a point was given to me to determine if constructive or destructive at that point. I found the wavelength is 100m and the path difference is 200m. How can I determine if it is...

What I am interested in here specifically is - how are bits represented? Is it as "1" is represented with a sent photon [at those specific frequencies] and "0" with a .. silence (no photon sent) ? ... but this, in that case, would get really complicated, because other photons from other...

Hi All, I wonder if the modulation of RF waves (Amplitude Modulation, Frequency Modulation, and Phase Modulation) can be explained in terms of photons. Thanks, Srini

Hi guys, We all know that a shadow could be generated by radiating light waves to an object. Would it be possible to design a system with radio waves, an object made by a special material and a sensor plane in order to create a shadow of the object on the plane? Cheers!

Hello everyone! I was just thinking about whether it will be possible to utilise the energy transmitted through the radio waves to produce back electricity for a household. Most of the houses in the world are blanketed by radio waves from all directions. Will it be possible to use an antenna...

Hello all I have been trying for sometime now to find the effects that magnetic field has on radio waves (such as cell phone signals and wireless broadband signals). If anyone of you could guide me towards right direction, would be very much appreciated! Thanks Ashutosh

I am working on an independent project at A level and have chosen to look at scavanging energy from radio waves. i have built a rectifier circuit and tested various types of dipole to induce a dc current. so far so good, got some very good results. however, there is very little...

I have a challenging question about electromagnetics. I presume if two antennas were designed to broadcast the same signal, but were designed somehow be exactly phase shifted by 180 degrees. And the antennas were stationed very close together. So that no electromagentic noise would be detected...

Can anyone give me a good, concise explanation of how radio waves are generated and used? I've searched a lot around the net for a good explanation, but all I can find is info about how antennas are oscillated at specific frequencies to produce radiation at the same frequencies...I want to know...

If our temperature is already above the necessary temperature to emit radio waves? At our temperature we emit mainly infrared right?

Because they don't have enough energy to be noticed? If I understand right, they are not energized enough to ecxite electrons?

I work in wildlife science. I track radio tagged animals, and am wondering if it's possible to make a radio wave camera, that can detect and visualize radio waves on a screen. I could use this camera to see the source of a radio signal (i.e. which bush or tree an animal is hiding in). This...

I know that chemical reactions can emit light and heat, and these are part of the electromagnetic spectrum. But are there any chemical reactions that can directly produce electromagnetic emissions in the radio part of the spectrum?

If infared radiation is responsible for somethings heat, why do microwaves use radio waves?

I’ve heard that the reason radio telescope dishes can be made out of wire mesh is because, so long as the size of the holes is less than (I believe) 1/10 the wavelength of the radio wave, the wave be reflected (it will see the dish as being solid). I was wondering what the physical reason was...

Hey guys, been trying to Google tons of things but am striking out. I'm curious how the process of sending and receiving radio waves works. What I'm looking for, more specifically, is how do you send specific wavelengths and amplitudes and then once those waves are airborne, how do you create...

i was trying to look for which forum to put this in so sorry if its in the wrong one. :D Im working on a project and i need a material that is able to reflect radio waves, like a mirror reflects light. any ideas for which material will reflect?

When radio waves go through certain walls , I was reading about this , do they go through the wall because their wavelength is too long to interact with the matter in the wall , Does it haft to do with the crystal spacing in the matter , and in some cases is it like light going through...

Homework Statement Typical AM radio waves usually have a frequency between 540 kHz and 1400 kHz. FM radio waves tend to have frequencies between 89 MHz and 105 MHz. Both types of waves travel at the speed of light. In terms of diffraction, use this information to help explain why in many low...

Hello, I've been puzzling over how radio waves and other EMR are formed at the subatomic level. I understand how to produce radio waves using a function generator but I do not understand how an antenna can emit a radio wave (among other types of EMR). I've asked several people this, but all...

photon refers to radio waves or not? the definition of photon refers the photon as the quantum of the electromagnetic field , however on the courses of physics(high school) when i said that, the teacher claimed that I'm wrong and photon refers only to visible light. who was wrong and why?thank you.

Good day everyone. I'm starting to become interested in listening to radio waves. I'm very new, just reading generally on what types of radios waves exist and what they are used for. However, mostly my interest is in the area is of the sounds of these waves. I'm wondering if there are any...