AM/FM Radio Waves & Diffraction

[kylepetten]

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 lying valleys in mountainous regions, AM reception is much clearer than FM reception.

Homework Equations

nil.

The Attempt at a Solution

Well, I'm not so sure. I know that the FM waves obviously have a higher frequency so I am guessing that the answer lies somewhere there. Could someone give me the jump-start that I need to get going on this question? Thanks a lot!

 

[thebigstar25]

try to explain it in terms of wavelength ..

 

[Awsom Guy]

I assume it is because of that am relies on amplitude and fm relies on frequency.

 

[Dadface]

The key word is in your title..."diffraction".What is diffraction and which of the two waves diffract the most?

 

[Awsom Guy]

OK. this is why, FM radio broadcasts travel at a thing called "straight line". Thus they pretty much only travel at straight lines (Sort of, but you get the picture) so if anything like a mountain or a wall comes in its way it will be interfered. But AM doesn't do this, it travles around the mountain or wall. But they have invented a thing called digital radio. This is better quality to FM and has better signal. It is the same as digital television (if you know what that is).