Grumpy: I think you hit the head on the nail. Let me just go over the quiz questions: Question 2: For air it's 1.00000037
What's going on there? Why is the relative permeability of air that value? What is that saying to you? So there is something in the air that has a very very slight magnetic dipole that will align itself in a magnetic field. The most important point being that the effect is microscopic and you can ignore it. It could be water molecules like you said or some other air molecule, oxygen, nitrogen, carbon dioxide, whatever. Knowing precisely what it is is not important for this discussion. Question 1: the strength was increased and attributed this to increased permeability of the air around the magnet This came from a book written in 1912. Now that we know about air's relative permeability, the statement above is bogus. It's impossible for the air to "increase in permeability," it's pure nonsense. It's electromagnetic mysticism. When I first read that a flag went up right away. So I suppose I am suggesting that you don't take in information without considering its validity yourselves first. If something sounds strange, doesn't feel right, why not discuss it?! Just a comment or two about some other points: Permeability and permitivity of air vary with pressure. These properties probably also change when the medium is polarized, but I have not been able to confirm this. Tesla did some experiments where he measured the change in capacitance with altitude while at Colorado Springs. I'd like to know if permeability of vacuum also increases when an electrostatic field is applied to a magnet. If the increase in permeabilty is large enough, it may be possible to utilize this effect to achieve gain since you are just applying a potential. I suggest that you review this stuff. By definition, the permeability of a vacuum cannot change. For capacitance changing with altitude, it's a strange statement that doesn't really make sense. Understanding these two properties is probably an interesting Wiki read. A great thing to look up that is directly related to this is the "impedance of free space" which is about 377 ohms. I am just pasting this because the first search result does not give you too much info: Mathematically, the Z o of free space (a.k.a. the impedance of free space) is equal to the square root of the ratio of the permeability of free space (µ o ) in henrys per meter ( H/m ) to the permittivity of free space ( o ) in farads per meter ( F/m ): A final comment from the peanut gallery is if you do some reading you will find out that the impedance of free space determines the speed of light, "c." MileHigh
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Topic: copper vs iron core (Read 41214 times)
