What Is the Rate of Energy Transfer for a 0.050T EM Wave?

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Homework Help Overview

The discussion revolves around calculating the rate of energy transfer for an electromagnetic (EM) wave with a specified magnetic field strength of 0.050T. Participants are exploring the relationship between the magnetic field and the corresponding electric field, as well as the implications of air breakdown in the context of the problem.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the application of Poynting's theorem and its relevance to the problem. There are questions about the Poynting vector and its components, as well as the significance of the air breakdown threshold mentioned in the original post.

Discussion Status

Some participants are seeking clarification on the concepts involved, while others are attempting to connect the equations provided to the problem at hand. There is an ongoing exploration of the relationship between the electric and magnetic fields in the context of energy transfer.

Contextual Notes

There is a mention of air breakdown occurring at a specific electric field strength, which may influence the discussion but is noted as potentially not directly relevant to the calculations being discussed.

lloyd21
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Homework Statement


It is fairly easy to produce a static magnetic field of 0.050T in the lab. If an EM wave could be produced with maximum magnetic field, Bo = 0.050T

a) what would be the rate of energy transfer (W/m2) ?

b) what would the corresponding maximum electric field be?

Note * Air "breaks down" at E = 3 x 10^6 V/m, that is sparks will jump across such a field.

Homework Equations


B= E / c
c = speed of light in vacuum

The Attempt at a Solution


0.050T (3.0 x 10^8 m/s) = 1.5 x 10^7 (electric field ?)
 
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lloyd21 said:
2. Homework Equations
What about (the 'microscopic' version of) Poynting's theorem?
 
Im not familiar with that?
 
S= (1/Mo)(E)(B) ?
whats the S, and why is there a not about the air break down
 
lloyd21 said:
S= (1/Mo)(E)(B) ?
whats the S, and why is there a not about the air break down
S is the Poynting vector, and it's a cross product of E and B. But look a bit further down and you will see an expression for energy density. I thought that would be relevant to the question. Of course, that form is for a vacuum. Maybe you need a variant for air.

I don't think the note about air breakdown is relevant to answering the question. More likely it is for understanding the inference of the answer.

Having said all that, I'm no expert in this area.
 

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