Question

how does cutting flux lines create current.though iam familiar with the concepts of faraday's law iam still not getting the actual physical picture.

Answer 1

well.. one way you can get some insight is , if your conductor cuts magnetic flux lines (movin g in a Bfield), since your conductor has electrons, these electrons will experience a force magnetic lorentz force.. for positive charge in one direction and negative electrons in the other direction. this creates an electric field..

Answer 2

ok..but what is exactly the meaning of 'cutting' flux lines..and doesn't cutting a flux line violate the law that mag flux lines are continuous originating from north pole and ending in south pole?

Answer 3

The way I understand it is like this. If you have a magnetic field going through the air with a relative permeability of 1. And then you bring a ferromagnetic material into that field with a relative permeability of say 5000 the flux lines are going to want to go through the metal more so than they go through the air. The reluctance of the metal is much lower than the air due to its high relative permeability. It is similar to current wants to follow the path of least resistance so magnetic flux wants to follow the path of least reluctance. So as you move a ferromagnetic material inside the magnetic field those field lines are going to follow the metal around. This is what is meant by cutting flux lines. As the magnet flux lines change with the moving metal object this is a changing magnetic field and if you have a current carrying conductor in this magnetic field a voltage will be produced according to Faraday. Here is a video:

http://www.youtube.com/watch?v=OUM5Eu2aJEE