# What is flux?

1. Sep 8, 2006

### HeilPhysicsPhysics

I don't understand what is the meaning of "flux" .I just know it has some relation between eletromagnetism.Please explain what is flux to me.

2. Sep 8, 2006

### Astronuc

Staff Emeritus
It could mean field lines (e.g. magnetic flux) per unit area or flow (photons) per unit area.

Or generally flux is the rate of transfer of fluid, particles, or energy across a given surface.

3. Sep 10, 2006

### Slayer26M

4. Sep 10, 2006

### Gokul43201

Staff Emeritus
A flux is the value of the surface integral of any vector field. If the field is constant over the area of interest, the flux is simply the product of the field and the area. Conversely, the magnitude of the field is given by the flux per unit area.

5. Sep 10, 2006

### Andrew Mason

Provided the area and field are perpendicular, of course (the surface integral being the integral of the dot product of the field and the area over the surface).

AM

6. Sep 10, 2006

### Gokul43201

Staff Emeritus
Dot products are products too!!

Yes, I should have been more clear. Thanks for fixing that.

7. Jan 20, 2012

### sharks

An easier way of visualizing this: Flux is surface bombardment rate.