Where does the Symbol B for Magnetic Flux Density Come From?

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Discussion Overview

The discussion centers on the origin of the symbol "B" for magnetic flux density in physics. Participants explore historical references and potential reasons for the choice of this symbol, considering its implications in the context of magnetic fields and related concepts.

Discussion Character

  • Exploratory
  • Historical

Main Points Raised

  • One participant notes that Maxwell used the German script B for "magnetic induction" but does not clarify the reason for this choice.
  • Another suggests researching earlier figures like Faraday or Ampere to find the origins of the symbol.
  • A student expresses frustration at the lack of clear answers and speculates that there may be no reason for the choice of "B".
  • There is mention of "wb" as the abbreviation for the SI unit of magnetic flux, which is named after Wilhelm Weber, but its connection to "B" is unclear.
  • One participant proposes that "B" and "H" might have been chosen because they were the first letters alphabetically not already in use in Maxwell's equations.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the origin of the symbol "B" for magnetic flux density, and multiple competing views and uncertainties remain regarding its historical context.

Contextual Notes

The discussion highlights the lack of definitive historical documentation regarding the choice of the symbol "B", and the reliance on interpretations of Maxwell's work and earlier physicists.

thebigcheese
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In physics we are learning about Magnetic fiex densities and have been taught that that the symbol for Magnetic flux density is B, however I cannot find where this letter comes from.

I know 'I' came about because they fought it was the 'intensity' of current and didnt know any different.

However if anyone can shed any light about where or what B stood for I would be very grateful.
 
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That is an interesting question to research historically.
In Maxwell's treatise (1873), he used the German script B for
what he called "magnetic induction" and the German script H for what he called "magnetic force". I consider both terms archaic today.
He does not indicate why he uses B and H, but gives a reference
(with no details) to Sir William Thomson.
You would have to go back to before Maxwell to find out who and why chose B (or H). Try researching Faraday or Ampere.
 
umm...hi

I'm currently a physics student in 11th grade. My teacher would give us extra credit if we find out why "B" is used for Magnetic Field strength. I've been looking for it for hours and I'm completely stumped. I'm beginning to believe there is no reason. Pretty cruel joke...
 
Your teacher probably knows the answer. Please post it here when he tells you. You could try going to the library and looking through biographies of Faraday and Amper.
 
Still no answer. Looking it up I have found another magnetic thingy is 'wb' prehaps they just dropped the w?
 
"wb" (abbreviation for "weber") is the SI unit of magnetic flux, which nowadays has the symbol \Phi or \Phi_B. It's named after the German physicist Wilhelm Weber.
 
thebigcheese said:
Still no answer. Looking it up I have found another magnetic thingy is 'wb' prehaps they just dropped the w?
The "Weber" was chosen as a unit 100 years after Maxwell used B for Magnetic field. You might try looking in a German or Latin dictionary.
 
B (and H) may have been the first letters alphabetically that weren't in use when Maxwell was writing his equations. Just a guess.
 

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