B EM Radiation Amplitude: Is Peak Related to Intensity?

AI Thread Summary
Electromagnetic radiation consists of sinusoidal electric and magnetic fields, with intensity defined as Power Flux Density (PFD) in watts per square meter (W/m2). The relationship between the RMS amplitudes of these fields and PFD is established through the intrinsic impedance of the medium, which is 377 Ohms for free space. For peak amplitudes, the PFD is halved compared to RMS values. The equations PFD = E^2 / R and PFD = R H^2 illustrate the connection between electric field (E), magnetic field (H), and intensity. Understanding these relationships is crucial for analyzing electromagnetic radiation properties.
jeremyfiennes
Messages
323
Reaction score
17
Electromagnetic radiation is propagating sinusoidal electric and magnetic fields. Are the peak amplitudes of these fields in any way related to the radiation's other parameters, e.g. its instensity?
 
Physics news on Phys.org
jeremyfiennes said:
Electromagnetic radiation is propagating sinusoidal electric and magnetic fields. Are the peak amplitudes of these fields in any way related to the radiation's other parameters, e.g. its instensity?
Intensity is Power Flux Density, expressed in W/m2. The RMS amplitudes of the electric and magnetic fields are related to PFD in the following way, where R is the intrinsic impedance of the medium, 377 Ohms for free space:-
PFD = E^2 /R
PFD = R H^2
R = E/H
If using peak amplitudes rather than RMS, the PFD will be halved.
 
  • Like
Likes jeremyfiennes
Thanks.
 
Thread 'Motional EMF in Faraday disc, co-rotating magnet axial mean flux'
So here is the motional EMF formula. Now I understand the standard Faraday paradox that an axis symmetric field source (like a speaker motor ring magnet) has a magnetic field that is frame invariant under rotation around axis of symmetry. The field is static whether you rotate the magnet or not. So far so good. What puzzles me is this , there is a term average magnetic flux or "azimuthal mean" , this term describes the average magnetic field through the area swept by the rotating Faraday...

Similar threads

Back
Top