Electromagnetic Waves: Energy & Amplitude Connection

[FizixFreak]

we know that the energy of electromegnatic waves depends upon there frequency (wave length as well) but does the amplitude of the waves have anything to do with the energy of the em waves?

 

[Gerenuk]

If I'm correct, then only the energy of one single photon depends on frequency. However, the power of incident EM radiation depends on both energy of each photon and their density. The density of the photons is represented by the amplitude of the EM wave.

 

[jtbell]

See also this post:

https://www.physicsforums.com/showpost.php?p=2578022&postcount=10

(By the way, it's "magnetic" not "megnatic" which I see you've written in two different threads.)

 

[FizixFreak]

If I'm correct, then only the energy of one single photon depends on frequency. However, the power of incident EM radiation depends on both energy of each photon and their density. The density of the photons is represented by the amplitude of the EM wave.

so indirectly the energy depends upon the amplitude of the incident wave ?

 

[Gerenuk]

Actually rather directly. But note that an EM wave has rather an energy density. The energy you can only define once you've specified how much volume of the wave you want to consider. A wave is not a particle with fixed dimensions!

 

[FizixFreak]

Actually rather directly. But note that an EM wave has rather an energy density. The energy you can only define once you've specified how much volume of the wave you want to consider. A wave is not a particle with fixed dimensions!

so the energy assosiated with a single photon depends upon the frequency but the energy of the entire wave is also related to the density of the photons the density of the photons is just as much as the amplitude of the incident wave right ??

 

[Gerenuk]

so the energy assosiated with a single photon depends upon the frequency but the energy of the entire wave is also related to the density of the photons the density of the photons is just as much as the amplitude of the incident wave right ??

Yes - at least that was what I had in mind. Feel free to cross-check with the other thread in this forum :)

 

[FizixFreak]

here is another one
the density of incident radiation depends on which factors ?