Electric & Magnetic Fields Out of Phase: Why?

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Discussion Overview

The discussion revolves around the phase relationship between electric and magnetic fields in electromagnetic waves, particularly focusing on conditions under which they may not be in phase. The scope includes theoretical considerations and implications in different media, such as free space and conductors.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the possibility of having an electromagnetic wave where the electric and magnetic fields are not in phase.
  • Another participant asserts that in free space or idealized loss-less dielectrics, the fields are in phase, but introduces the idea that in real dielectrics with losses, the fields can be out of phase.
  • It is noted that in good conductors, the electric and magnetic fields can be 45 degrees out of phase.
  • A participant seeks clarification on whether the 45 degrees phase difference applies to waves propagating inside the conductor, which is confirmed by another participant.
  • A request is made for an analytical solution to demonstrate the 45 degrees phase difference in perfect conductors, indicating a willingness to engage with the mathematical aspects of the topic.
  • A reference to external material is provided as a potential resource for understanding the phase relationship in conductors.

Areas of Agreement / Disagreement

Participants express differing views on the phase relationship of electric and magnetic fields in various media, indicating that multiple competing perspectives remain without a consensus on the conditions under which the fields may be out of phase.

Contextual Notes

The discussion does not resolve the mathematical details or assumptions regarding the phase relationship in different media, leaving open questions about the analytical solutions and specific conditions that lead to the observed phase differences.

Shailesh Pincha
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Why can't we have an Electromagnetic wave in which the Electric Field and Magentic Field aren't in phase?
 
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You can - it depends on the medium in which the wave is propagating. In free space or an idealized loss-less dielectric they are in phase. Once you add a little loss in the dielectric (as all real dielectrics have) then the fields are no longer exactly in phase. In a good conductor the electric and magnetic fields are 45 degrees out of phase.

jason
 
In a good conductor the electric and magnetic fields are 45 degrees out of phase.

jason
Is the 45 degrees for a wave propagating inside the conductor? Thank you.
 
Last edited by a moderator:
Is the 45 degrees for a wave propagating inside the conductor? Thank you.
Yes.
 
Last edited by a moderator:
Is there an analytical solution to show that E and M fields in a perfect conductor are out of phase by 45 degrees? (I can handle the calculus.)
 

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