Why is it not possible for two magnetic field lines to cross???

Question

Having difficulty answering this question, any help would be nice.

Answer 1

intersting one...

Have you heard of anything called the resultant force. ?
Well this is the reason for two magnetic lines not to cross.

Magnetic field, it has a direction, its actually a vector not a scalar. When ever there are two or more vectors overlapping at one point what we actually see is the resultant of all of them.
take an example...
consider a boat which is trying to cross the river across. Now the river flows down & that force is acted on the boat. at the same time the man who rows it applies a force perpendicular to the flow of the river...
Now what direction will the boat go.??
Its not perpendicular to the flow of the river or along the river.. Its some diretion diagonal... Now apply the same thing to magnetic fields. when ever there are two or more forces (not parrelal) the result is the resultant force acting on it...

Hope this clears things up...

Cheers
Codered

Answer 2

Who says it's not possible. It's not possible when a single source of the field is used. But two different sources (e.g., two magnetic horseshoes) can certainly cross fields.

In case you don't believe it. Get two magnets. Sprinkle some iron filings over a sheet of white paper. Move the magnets under the paper covered with the filings. Shake the paper slightly and watch the filing align with the force fields from the magnets.

You will see that the force fields can and do cross when the magnets are placed just so. Put just one magnet under the paper and shake. This time you'll see the lines of force do not cross; they are more or less parallel, depending on how close to the source (N or S poles) the filings are.

Each field force line is generated in a natural magnet by the alignment of the iron atoms in the magnet. This is why the iron is magnetized, the atoms and their electrons are "spinning" in the same direction, causing the magnetic lines of force to emanate in the same direction. But then, as the opposite pole takes charge, the lines of force bend back towards the other pole. And enter that pole parallel because the atoms are facing the same direction there as well.

Answer 3

At the the point they cross, the magnetic field would have two different directions. Since the magnetic field at any point must have only one direction, two magnetic field lines cannot cross.

Answer 4

Two magnetic field lines never cross ----i.e. by definition of magnetic lines of force. Of course, this is true based on one source only as implied in your question.