What is the Relationship Between Electromagnetic Amplitude and Power?

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Determining the amplitude of electromagnetic waves involves understanding its relationship to irradiance, which is the power per unit area measured in watts per square meter. The amplitude can be inferred from the square root of the irradiance, assuming the wave is monochromatic. To measure amplitude directly, one typically assesses the power or intensity of the wave. The discussion highlights the importance of these measurements in calculating amplitude in terms of energy and frequency. Overall, measuring power or irradiance is the most straightforward method to derive amplitude.
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Hi, I have a question about electromagnetic amplitudes. we can easily find the wavelength of any EM, but how do we determine its amplitude? in terms of joules vs. length vs. frequency?
 
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I don't understand your question. How do you measure amplitude? or how do you calculate it given something else?
 
The square of the amplitude [of the electric field carried by the wave] is proportional to the irradience (intensity) of the wave, which is the power per unit area and hence has SI units of watts per square meter (W.m-2)
 
The easiest way is to measure the power or irradiance and infer the amplitude from there, assuming of course that the wave is monochromatic, infinite etc. etc.

Claude.
 
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