Electric Field and Magnetic Conversion

  • #1
In the solutions of a particular problem, it was stated that:

<P> = 1/2 |S| = 1/(2μ0) * E^2 / c

Where <P> is the average power, S is the Poynting vector.

From the above equation does that mean: B = E /(2μ0c) ?

I was just wondering how you can show the above relation between Magnetic and Electric field.
 
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Answers and Replies

  • #2
marcusl
Science Advisor
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No it doesn't. The Poynting vector is [tex]\mathbf S=\frac{1}{\mu_0} \mathbf E \times \mathbf B[/tex]
and, for a wave propagating in free space, B and E are normal to each other (and to the direction of propagation) and have magnitude [itex]B = \frac{1}{c} E[/itex]. Look it up. When you take a time average to get power, it devolves to your first expression.
 
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  • #3
Oh ok, thanks.
 
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