Regards,
FL
It is known as Gauss's Law for Magnetism, and is also one of Maxwell's Equations.
The equation demonstrates that there are no magnetic monopoles. You DO know the difference between a dipole and a monopole, don't you _Jim? A bit rusty on your Physics?
BTW, you DO know what type of integral that is, don't you _Jim? Or are you a little rusty on your Math as well?