# Magnetic flux

1. Feb 15, 2008

### v_pino

What is the definition of Magnetic Flux?

My textbook tells me that it may be 'visualised as the total number of magnetic field lines rather tan their concentration... be aware that this is NOT a definition.'

thank you

2. Feb 15, 2008

### Defennder

Have you learnt what is electric flux yet? If so, magnetic flux is the same as electric flux when you replace the electric field with a magnetic one. But probably you haven't since otherwise you would have understood it easily. Just think of it this way: Suppose you have a magnetic field and you want to know how much of the magnetic field passes through a specified plane surface. Just visualise it as magnetic field lines passing through that plane surface. The magnetic flux would then be the dot product of the magnetic field B with the surface area represented as a vector A normal to the surface. The surface integral is used to represent the summation of all the magnetic flux measured at any area element dA on your surface.

See: http://en.wikipedia.org/wiki/Magnetic_flux