What Are the Dimensions of Permeability and Permittivity?

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Discussion Overview

The discussion revolves around the definitions and dimensions of permeability and permittivity, exploring their roles in electromagnetism and the relationship expressed by the equation εμ = 1/c^2. Participants seek detailed explanations and insights into these physical quantities.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant requests a detailed definition of permeability and permittivity, noting their proportionality and questioning their interpretation.
  • Another participant recommends a text titled "The Electromagnetic Interaction" for a good description of the concepts.
  • A third participant suggests checking Wikipedia articles on permittivity and permeability for additional information.
  • A later reply emphasizes the importance of dimensional analysis in understanding physical quantities, particularly in the context of electromagnetism in a vacuum, and connects this to the speed of light.

Areas of Agreement / Disagreement

Participants express varying approaches to understanding permeability and permittivity, with no consensus reached on a singular definition or interpretation. Multiple viewpoints and resources are shared without resolution of the initial inquiry.

Contextual Notes

The discussion includes assumptions about the relevance of dimensional analysis and the specific context of electromagnetism in a vacuum, which may not apply universally. The relationship between permeability, permittivity, and the speed of light is mentioned but not fully explored.

einsteinian77
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Could someone please tell me the most detailed and direct definition of permeability and permittivity. I know that they are porportionalities of some sort but what else could they be viewed as? Why is εμ = 1/c^2 ?
 
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There's a text called

"The Electromagnetic Interaction" which gives quite a good description. I highly recommend it.
 
Originally posted by einsteinian77
Could someone please tell me the most detailed and direct definition of permeability and permittivity. I know that they are porportionalities of some sort but what else could they be viewed as? Why is εμ = 1/c^2 ?

Here's a tip. Often, when you've got some physical quantity that you don't understand, it helps to determine it's dimensional units. On the left hand side of the above expression, the dimensional units of a speed is involved. The next step is to identify what constants are available in the problem. For example, if the setting is electromagnitism in a vacuum, there's only one relevant constant with those dimensions, namely the speed of light.

This kind of dimensional analysis may not immediately clear everything up for you, but it can point you in the right direction.
 
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