Need Help Understanding Electric Flux and Electric Flux Density

[Shreya]

Homework Statement

What is Electric Flux?
What is the difference between Electric Flux and electric flux density?

Relevant Equations

Electric Flux = E*ds cos (theta)

I don't understand the exact meaning of flux.
Please be kind to help.

 

[Gordianus]

Have you ever computed the flux of any vector field?

 

[anuttarasammyak]

The relevant equation
$$\mathbf{E}\cdot\mathbf{dS}$$
is a definition of flux or flow of vector field E on surface dS. It is interpreted as a quantity flow passing through surface $\mathbf{dS}=\mathbf{n} dS$.
Its (surface) density is $$\frac{\mathbf{E}\cdot\mathbf{dS}}{dS}=\mathbf{E}\cdot\mathbf{n}$$
which requires orientation of the surface.

 

[Shreya]

Have you ever computed the flux of any vector field?

No, but I learned abt Volume flux as volume passing through an area per unit time

 

[Shreya]

The relevant equation
$$\mathbf{E}\cdot\mathbf{dS}$$
is a definition of flux or flow of vector field E on surface dS. It is interpreted as a quantity flow passing through surface $\mathbf{dS}=\mathbf{n} dS$.
Its (surface) density is $$\frac{\mathbf{E}\cdot\mathbf{dS}}{dS}=\mathbf{E}\cdot\mathbf{n}$$
which requires orientation of the surface.

Thanks a lot!
Can you please explain the difference between electric flux and electric flux density?
Is electric flux density = electric field ?
Please help

 

[anuttarasammyak]

Is electric flux density = electric field ?

The last line of post #3 is electric flux density for given infinite area $\mathbf{dS}$.

Electric displacement field $\mathbf{D}$ is (was ?) called electric flux density but is something different from the above mathematics.　Along the same discussion I wonder magnetic flux density is proper as one of the names of $\mathbf{B}$. I should appreciate the advice of senior learners.

 

[Shreya]

Got this image from a source: I think it confirms what anuttarasammyk has said, Thank
You!