New chapter! Let’s start off with a very important concept:
- Magnetic Flux
- Φ = BA sin θ
Now we turn to a similar term:
What is magnetic flux?
The product of magnetic flux density & cross-sectional area normal to the lines of flux.
It is represented by Φ
For a uniform field B making an angle θ with a cross-sectional area A,
Φ = BA sin θ
Its unit is the weber (Wb)
1 Weber is equal to 1 Tesla multiplied by 1 meter-squared
Wb = Tm2
Confusing? Let’s look at that 3D image illustrating B again:
Let’s look at the general case now:
Now let’s compare different cross-sections for different areas & different magnets:
|Magnetic flux density (B) is represented by the number of lines passing through an area PER UNIT AREA.||Magnetic flux (Φ) is represented by the number of lines passing through an area.|
|These areas have the SAME magnetic flux density, B.|
They have the same density of lines, so the STRENGTH of the magnetic field is the same.
|These areas have DIFFERENT magnetic flux, Φ.|
They have a different total number of lines.
|These areas have DIFFERENT magnetic flux density, B.|
They have different densities of lines, so the STRENGTH of the magnetic field is different.
|These areas have the SAME magnetic flux, Φ.|
They have the same total number of lines.
We’ve seen why flux density is so important – it is useful in calculating the forces exerted by a magnetic field.
Why is magnetic flux so important?
It is useful in explaining Electromagnetic Induction.
We’ll cover that in my next post – see you there!