Best answer will be selected!; What is flux density?

Question

I found stuff like:

The magnetic flux it is the product of area & magnetic flux component. The magnetic flux density is numerically measured by the number of magnetic flux lines passing perpendicular to a unit area surrounding that point & it is measured in Tesla. (from Yahoo! Answers).

and

the rate of mass flow across a unit area (Wikipedia).

The problem is that I can't really figure it out from these sources. Furthermore, I need to know how and why flux density changes. If someone could explain this to me in somewhat simple english, I would greatly appreaciate this. Thanks!

Answer 1

Ok, this is going to be confusing but I will try. Flux is simply a vector of anything cutting through a surface. To try and simplify that further, imagine a cup with straws in it. The straws would be a vector cutting through the area of the top cup the cup (imagine you are looking down on the glass so that the rim of the glass just looks like a circle with straws in it). Flux is anything passing through a surface, so flux density is going to be the amount of stuff passing through a surface divided by the area of the surface.



It would help if you could tell us how this is being used. Electric fields, Magnetic fields, etc.



Edit: I forgot to explain how flux density changes. Well it can change if you have a larger area capturing a certain amount of vectors, or a bigger cup with the same amount of straws. Or it could change if you have more straws in the same cup. Or the same area with larger vector quantities. And just to clarify I am saying straws because they are passing through the area of the rim of the cup. So when thinking of flux think of it as passing through a certain area. The person's above me explanation of flux is a little bit hard to follow, but gives a better definition.

Answer 2

Well the way I understand flux is "flow". If you've got a circular loop that is below a large faucet, a certain amount of water will pass through the loop. When the loop is facing the faucet, there is a lot of water "flow" or flux through the loop. When you start making the face of the loop turn away from the faucet, less water flows through, so there is less flux. The extreme of this is if the loop points faces sideways. Then there is no flow or flux. So flux depends on how the line of water falling and the area of the loop line up.



As far as flux density goes, it probably means that for a given alignment of the water falling and the loop's area, we could change how much water goes through by actually changing the faucet settings, so instead of a few drops, you've got a richer stream.

Answer 3

Flux density is the mass per cubic inch of the trash in the tank when the Delorean reaches 88 mph. At this speed, the density of said trash spontaneously decreases to near zero, slingshotting the Delorean back to 1955.

Without the Flux capacitor, none of this would be possible

Answer 4

Imagine a faucet that squirts water in every direction (spherically). It's sort of floating in space, not attached to your kitchen sink or anything.



Now let's say you put a big spherical sieve over the whole faucet, so that it was completely enclosed.



How much water is coming out of the sieve in one second? It has to be equal to the amount of water coming out of the spigot in one second.



If your sieve was even bigger, the same has to be true...that the amount of water coming out of the big sieve in one second has to equal the amount coming out of the small sieve in one second, and they both equal the amount coming out of the faucet in one second.



The flux density is the same thing: The flux is the amount of water per second, and flux density is the amount of water per second per surface area. (The relationship to volume is given by stoke's theorem.)



Edit: If you wanted to change the flux density, you could either make the sieve bigger or smaller (it would have more/less surface area for the water to pass through) or you could adjust how much water comes out of the faucet.



Hope this helps.