Area & Magnetic Field

[SaintJude]

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Which equation relates relationship between the magnetic field & the area of the coil?

It supposedly includes electric permittivity of free space ε0

 

[chiddler]

the closest I can think of is gauss's law (E field, though). I remember maxwell's equations having a lot of those constants in them, but I don't think we have to know them for the mcat.

Maybe you meant ampere's law? B = μ*I/2πr?

 

[MedPR]

Which equation relates relationship between the magnetic field & the area of the coil?

It supposedly includes electric permittivity of free space ε0

Well Flux=B*A.

And according to wiki: http://en.wikipedia.org/wiki/Magnetic_flux#Comparison_with_electric_flux

Flux=Q/ε0

So Q/ε0=B*A

Is that what you were talking about? Either way, like chiddler said I think the only equation we need to know here is Flux=BA

 

[SaintJude]

Thanks you two replying. The question is from Kaplan Qbank and they ask for a graph that "represents the relationship b/w the magnetic field & the area of the coil if everything else is fixed"

Then in the explanation the say: If you know the equation "ε0 = BAω" you can plot it..it's an inverse graph" Well, I don't know this equation, what it means, or where it comes from... 🙁 MedPr is this the same as the one you just posted?

The answer resembled this blue- graph:

Although I incorrectly chose this graph:

Apparently, it's a "common mistake" for people to chose this red graph, b/c they erroneously attribute it to an inverse relationship. I'm still a bit confused why this red graph is wrong.

 

[chiddler]

I don't think you need that equation. You can use flux = B*A

 

[milski]

The red graph is still proportional (aka linearly dependent), it just has a negative slope. You can write y=kx where k is negative. Another way to write that is y/x=const

Inversely proportional means yx=const or y=k*1/x. This will not be a straight line.