Can Granularity of Electromagnetic Radiation Be Neglected?

[Athalus]

I don't know what they mean in my assignment referring to granularity in question 3)e) of the assignment found below.

3) [5 marks] A radio station broadcasts at a frequency of 2MHz with a total radiated power of 1000W.
a. What is the wavelength of this radiation?
b. What is the energy of the individual quanta that compose the radiation?
c. How many photons are emitted per second?
d. A certain radio receiver must have 5 microwatts of radiation incident on its antenna in order to provide intelligible reception. How many photons per second are required?
e. In view of your answers to (c) and (d), can granularity of electromagnetic radiation in these circumstances be neglected?

I think it means the integrity of the signal, which i believe is good since the ratio of delivered power to that of the minimum required power is very high in the order of 10^8

Thanks for any clarification
Athalus

 

[dextercioby]

To answer your question from the title,i would say "granular=corpuscular" in this case "photonic"...Did u compute the number of photons??

Daniel.

 

[Athalus]

Yes I did compute the number of photons emitted per second in part c, approximately something in the order of 10^29 photons per second, and I calculated the minimum number of photons required in part d, approximately something in the order of 10^21 photons per second, I'm just wondering what they mean by granularity, which I think means is there sufficient photons so that granularity of the signal is not an issue, which I believe there is.

Thanks
Athalus

 

[dextercioby]

I don't feel like checking your numbers,they seem correct.If in the second case,the one with a small intensity,the nuber of photons is still big (10^{21}/s),then the "granularity" can be neglected,because the quantum effects,the ones which include the word "photon",are valid only when the nummer of particles is really small...The number you've got is HUGE...

Daniel.

 

[Athalus]

Thanks, but I still don't quite understand what your telling me, is it that granularity refers to what happens when there are quantum effects involved, and that I can disregard it because the number of photons is so large that quantum effects do not come into play?

Thanks Again,
Athalus

 

[dextercioby]

Thanks, but I still don't quite understand what your telling me, is it that granularity refers to what happens when there are quantum effects involved,

Yes,"granularity" of light is definitely a quantum effect.

and that I can disregard it because the number of photons is so large that quantum effects do not come into play?

Thanks Again,
Athalus

Éxactement,that's the explanation...You got the idea...Congratulations...


Daniel.

 

[Athalus]

But the question is not referring to the granularity of light, the question is referring to the "...granularity of electromagnetic radation...", or radio waves I believe, I don't know if it really matters though, it probably is the same thing as the granularity of light.

Thanks,
Athalus

 

[dextercioby]

Okay,light is em.radiation.It's just that it's in the visible spectrum.There are radio photons as well,just like gamma,X,visible...

Daniel.