Estimating Electromagnetic Radiation from a Cellular Phone

AI Thread Summary
The discussion centers on estimating the frequency and power of electromagnetic radiation emitted by a cellular phone during a call, as part of a graduate exam preparation. The original poster expresses confusion about how to approach the problem despite having relevant equations and background knowledge. Participants emphasize the need for more detailed work and suggest researching typical frequencies and power levels used by cell phones. They encourage the poster to demonstrate effort in applying the provided equations to derive an answer. Overall, the conversation highlights the importance of understanding the context and parameters of the problem in order to solve it effectively.
JordanD
Messages
7
Reaction score
0
Hello all,
I have a problem with a typical style of problem I seem to always struggle with. Just to clear this up, I am studying for my comprehensive exams later this summer. So I am going through past problems to bone up on the last two years of grad school. At which point I came across this type of problem that I see to always struggle with so I am here to gain some insight on how to do these problems and what is being asked of me. The question goes as such:

"Qualitatively estimate the frequency and power of electromagnetic radiation emitted by a cellular phone during a typical phone call."

Now there are a few things I know and a few things that are given on the exam:

I know P(r)=I(4πr2) and I=1/2ε0cE2

I am also given the equation for the "Time averaged power radiated per unit solid angle" (See Jackson eqn 9.56) with Z0=377Ω

Now I have given you everything I have been given, so my question stands. Obviously there should be enough info here seeing as this is a past comprehensive exam, but I don't have the foggiest idea how to start. I strongly feel like I don't have enough info to go forward with, but I know I am wrong. Any insight or advice is strongly appreciated.
 
Physics news on Phys.org
JordanD said:
"Qualitatively estimate the frequency and power of electromagnetic radiation emitted by a cellular phone during a typical phone call."
You have done nothing to answer this question. Please show us more work.

What frequencies are used for typical cell phones? What power do typical cell phones transmit? Please show more effort.
 
Last edited:
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top