# Homework Help: Discussion work on magnetic fields. (Clarification only)

1. Jul 21, 2012

### Physics_Dud

Specifically:
1. If there are two (horseshoe) magnets that are facing each (unlike poles facing ea) other and an iron ring is placed in between them. Why are there no magnetic fields inside the iron ring?

- As far as my understanding goes. I believe that theres no magnetic field inside the ring because the iron ring serves as something like a conductor whilst the air inside the ring serves as an insulator thus there are no magnetic fields inside the ring. Am I right?

Lastly...

2. Are there regions between permanent magnets where the magnetic field lines intersect? If yes where? If no why?

- There are no regions in the magnetic field where the magnetic field lines intersect. Simply because each magnetic field lines are distinctly unique with each other and do not intersect. If, however, they do intersect at one point, that would mean there are two values that can be acquired at that respective point and is completely impossible.
(I believe theres something lacking in my answer, like, theres an absence of a proof.

2. Jul 22, 2012

### sankalpmittal

Moreover , the magnetic field developed by the iron ring is such that at its very centre the field lines are almost parallel.

This is because , if they do intersect then it would mean that at "the point of intersection of two or more magnetic lines of force" , two or more tangents can be drawn showing that there are two or more possible directions for "the" magnetic field line. This is not so , as this would mean that you can throw a same ball by your same hand in two or more different directions at the same time ! Moreover existence-uniqueness theorem is violated. It states that here are unique solutions to the equations describing the magnetic field at each point in space.

3. Jul 30, 2012

### Physics_Dud

Thank you for the swift reply. I'm sorry I forgot to reply as well. But it really did help me alot on my lab report. Especially on the none intersection of magnetic field lines. ^_^