Radio waves Definition and 127 Threads

Assuming string theory is on the right track, would the electromagnetic field of some radio station antenna be given by some collective motion of string theory strings in their curled-up dimensions and the dimensions of space? If a string moves at the speed of light doesn't it have to be mass...

Is there a way to monitor and block intrusive radio waves?

I'm not knowledgeable about these things, with all the free energy nonsense I frequently see. So what do you think? http://tech.yahoo.com/blogs/null/143945 Does this sound right? If so, it looks like exciting news. Even for stand-by charging, that's still a good thing.

Homework Statement Two coherent sources of radio waves, A and B, are 5.00 meters apart. Each source emits waves with wavelength 6.00 meters. Consider points along the line connecting the two sources. At what distance from source A is there constructive interference between points A and B...

Homework Statement What is the percentage amplitude reduction of 10MHz radio waves that travel through 250 meters of water? Construct a plot of the average energy per unit volume stored in these radio waves as a function of depth from 0 to 250 meters in terms of the initial electric field at...

Hey all! Now I'm working on wireless communication, not a physician. In many courses in ECE, we learn about principle of superposition of radio waves. But I have a stupid question which has been considered no wonder so far. There are two radio senders(S1,S2) and one receiver(R). Let's...

Homework Statement Two coherent sources of radio waves, A and B, are 5.00 m apart. Each source emits waves with wavelength 6.00 m. Consider points only along the line connecting the two sources. (a) At what distance from source A is there constructive interference between points A and B...

Link: http://www.santafenewmexican.com/HealthandScience/LANL_scientist_makes_radio_waves_travel_faster_than_light Is this true ? Can radio waves or light really be send faster than light using a rapidly spinning magnetic field ? Sorry if there already was a thread about this, I couldn't...

Radio waves are electromagnetic.Right?? "Phoenix was on track for anticipated entry into the atmosphere at 4:30p.m. Pacific Time and reaching the surface at 4:38 p.m., although confirmation of those events comes no sooner than 15 minutes, 20 seconds later, due to the time needed for radio...

There are hundreds, if not thousands, of RF signals all around us from those at VLF frequencies to microwave frequencies and I suspect if you set up a very long random length of wire as an antenna, there would be a resulting induced electrical signal that is the sum (and differences) of all...

Let's say that you make a huge (radius of a few meters) coil of wire. Will radio waves cause a current to run through it? If so then how much? Thanks.

Homework Statement An AM radio station broadcasts with a power of 21.0 kW at a frequency of 910 kHz. Estimate the intensity of the radio wave at a point 18.0 km from the broadcast antenna. Homework Equations I= p/A I1/I2=r2^2/r1^2 w=2pi f The Attempt at a Solution From the...

Homework Statement AM radio allows a speration of 10kHz between frequencies of different radio stations. Why do AM radio receivers need a large Q? Estimate the Q required for good AM reception. The Attempt at a Solution I'm really not sure where to begin! :confused:

Hello, Can you please tell where radio waves originate from? Thanks, Glynis

hi all... Something doesn't quite add up here: A radio wave is an electromagentic wave, right. It therefore travels at the speed of light, right. Then why does it actually take a finite amount time (like secoonds or even miliseconds) to travel a couple of kilometers...

I was reading up on black holes when i thought of this. Black holes have been found to emit radio waves. I was wondering if this was actually light that managed to escape the black hole. Here is my thinking on this. From what i know light travels in a straight line through points through...

I know that electricity can be converted to microwaves obviously. But how is it converted to radio waves?

Hi everybody, it's nice to finally join the forum. I'm a little...:rolleyes:...:confused:. Is electric current (the kind we use at home) a form of radio waves occilating at very low frequencies? What are the all the simmilarities and differences between electric current and radio waves...

...efficently at night time? :zzz:

In a neon light, light is produced when voltage is applied to electrodes that ionize the gas in the tube. Is there any type of gas than can be ionized, and then produce light, by using radio waves as the energy source rather than electricity?

http://healthandfitness.sympatico.msn.ca/News/ContentPosting.aspx?contentid=85b9ce54b8824e2baa998e79f5ec2f1e&show=True&number=6&showbyline=False&subtitle=&detect=&abc=abc Do radio waves REALLY cause leukemia? Aren't they lower in wavelength than infra-red?

Hello, I am having difficulty answering the following problem: consider two antennas, separated by X meters that radiate in phase at f. A reciever placed 150 m from both antennas measures an intensity I_o. The reciever is moved so that it is 1.8 m closer to one antenna than ot the other...

I'm curious why can AM radio waves be heard on the other side of a mountain from where they are propogated and FM not? Thanks

Ok, so we all know that the shorter the wavelength, the higher the frequency, and the higher the photon energy for EM radiation. How does this relationship explain why X rays are highly dangerous to living things, and radio waves are not? Thanks in advance.

I doubt that my physics teacher (who is coincidentally Mark2711 on this forum) has found out the answer for this question that he was wondering about , so i have decided to take the initative and ask. We know that photons are the quantas of energy in the electromagnet spectrum. Well we know...

hi all, Can anyone tell me a easy way to create radio waves,micro waves reciver and emiter? I hope someone will help me. -benzun all for God.

Im not sure of this, but visible light is an EM wave just like radio waves are, right? If I am right, does that mean mirrors reflect all ranges of EM waves, radio included? Also what is it about a mirror that reflects photons?