Calculating the number of photons in a wave

[Daintyg]

Homework Statement

I am trying to answer a relatively simple question. I have been asked to compare the number of Photons in 100W light bulb and a 100W FM Radio per second. Having crunched the numbers it appears that an FM Radio wave gives out more Photons per second than a light bulb. Is this correct?

Homework Equations

I have used E=hc/λ

The Attempt at a Solution

I come out at 2.87x10E20 for a light (Using yellow) and 5.03x10E36 for a radio (the power depends on the wavelength)

 

[technician]

You are correct and presumably in your calculation you found that the energy of A radio photon is much less than the energy of a visible light photon.
A radio frequency is very much less than the frequency of visible light

 

[Daintyg]

Thank you, I was being a dumb arse.

 

[technician]

No comment
except to say... don't look at yourself like that.

 

[asteriatic]

Yes, your calculations are correct. The number of photons in a wave is directly proportional to the energy of the wave, which is represented by the frequency of the wave. As the frequency of the FM radio wave is much higher than that of the light bulb, it emits a significantly higher number of photons per second. This is due to the fact that the energy of a photon is directly proportional to its frequency, according to the equation E=hf. Therefore, a higher frequency wave will have a higher energy per photon, resulting in a higher number of photons being emitted per second.