The electric field strength H is defined in SI units as ampere turns per meter (A/m). In the older cgs system, it is referred to as Oersted (Oe). The distinction between magnetic field strength H and magnetic induction B is crucial, as B is often incorrectly labeled as the magnetic field. This confusion is addressed in Mel Schwartz's "Principles of Electrodynamics," where he emphasizes that B is the fundamental field while H is a subsidiary artifact. Understanding these units is essential for accurately plotting magnetic hysteresis curves.
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ultimateguy said:What are the units of the electric field strength H? I know that H = NI/L for a solenoid and I'm wondering if there is any condensed unit or if it is just ampere turns per meter.
That is one of the virtues of the "old" gaussian system.ultimateguy said:Thanks for the info. I was wondering because I'm plotting a magnetic hysteresis curve and have B vs. H and I didn't think they both had the same units.
More like a vice! I always wondered why people seemed so flippant about interchanging the magnetic flux and field. More often than not, you'll find B being referred to as the field! I guess this was the reason.Meir Achuz said:That is one of the virtues of the "old" gaussian system.
There B and H can have the same units so the hysteresis curve has a simple meaning.
Agreed, this is a nice feature of Gaussian units.Meir Achuz said:That is one of the virtues of the "old" gaussian system.
There B and H can have the same units so the hysteresis curve has a simple meaning. The gaussian unit for H is called "Oersted" for historical reasons, but it really is the same as the unit "gauss".
ObsessiveMathsFreak said:More like a vice! I always wondered why people seemed so flippant about interchanging the magnetic flux and field. More often than not, you'll find B being referred to as the field! I guess this was the reason.
Mel deserves his Nobel prize for that sentence alone.marcusl said:Agreed, this is a nice feature of Gaussian units.
You mean magnetic induction and field (flux is yet another quantity). Yes, many writers call B the magnetic field without explanation or comment. Mel Schwartz, in "Principles of Electrodynamics" (1972), is one of the few who are up front in addressing this:
At this point we interject a small bit of philosophy. It is customary to call B the magnetic induction and H the magnetic field strength. We reject this custom inasmuch as B is the truly fundamental field and H is a subsidiary artifact. We shall call B the magnetic field and leave the reader to deal with H as he pleases.