Does Magnetic Flux Remain Constant in Changing Magnetic Fields?

[21joanna12]

I know that the equation for magnetic flux is $\Phi=\int \vec{B} \cdot dA$. It seems to me that this is like integrating the density function a rod with respect to x, which simply gives you the mass which is constant. I was wondering whether the same thing applies here: is magnetic flux a constant?

 

[Matterwave]

In general, no it is not. A changing magnetic flux leads to an EMF by way of Farday's law.

 

[jtbell]

The density function $\rho(x)$ of a rod does not normally change, nor do its dimensions. The magnetic field $\vec B$ can change, and so can the boundary of the surface that we integrate over.