Magnet Myths and Misconceptions

[tinman]

@MarkE

I would like you to take some time and draw up an electromagnet the shape of a rod magnet-say 3 inches long and 1/2 inch in diameter for the core material. This will of course have the conductive wire wrapped around it. You will need 3 pictures/diagrams of this very same electromagnet. I would then like you to show the magnetic field building up around that electromagnet in three stages from the instant a current is applied to the inductor-i want to see this magnetic field build around the inductor. I know this happens at or close to the speed of light,but lets devide that by 3.
So we will have in the first diagram the field just starting to emerge,then the second diagram will show it half way built to its full potential,and the third will show the full field and strength of that field. I will then show and explain why there is no magnetic field at the cenetr point of that inductor/electromagnet between the two pole's.

I have done many experiments for you and others,so i hope you can take the time to draw these 3 simple diagrams.

P.S-you may use your fictional lines of force,and flow arrows for this experiment.

Brad

[MarkE]

Are you refering to me Mark?
First up,there are NO magnetic field lines of force-only a magnetic field.The strength of that field is as i have pictured it in my diagram. I can see once again i will be spending my time on something you could perform your self.No feromagnetic materia is attracted(or has a very weak attraction) to the center of a magnet where my lines cross.

So what denotes the intensity and orientation of the field in your diagram?  Is intensity the  distance from the dipole axis?

As to the claim: 

No feromagnetic materia is attracted(or has a very weak attraction) to the center of a magnet where my lines cross.

I can suggest several tests that will demonstrate that the field produced by your magnet is in fact quite strong in that region.  Here is one:

Take a piece of paper and an ordinary compass outside the strong influence of any magnets.  Mark on the paper the two compass axes:  North-South and East-West.  Next move the compass away and place a dipole magnet that is at least four times as long as the compass diameter and place that magnet on the East-West line on your paper.  Now, place the compass near the mid point of your magnet.  Does the compass return to align to the North-South line on your paper as it did when it was outside the influence of your magnet?  If as you assert the magnetic field strength has fallen to zero in that region, what is holding your compass pointing along the East - West line?  Move the magnet away from the compass.  Does the compass now return to aligning to the North-South line?  What can we conclude from the fact that the compass aligns to magnet axis that is perpendicular to the earth's magnetic North-South line even smack in the middle of the magnet where you contend the field strength has fallen to zero?

[tinman]

So what denotes the intensity and orientation of the field in your diagram?  Is intensity the  distance from the dipole axis?


Take a piece of paper and an ordinary compass outside the strong influence of any magnets.  Mark on the paper the two compass axes:  North-South and East-West.  Next move the compass away and place a dipole magnet that is at least four times as long as the compass diameter and place that magnet on the East-West line on your paper.  Now, place the compass near the mid point of your magnet.  Does the compass return to align to the North-South line on your paper as it did when it was outside the influence of your magnet?  If as you assert the magnetic field strength has fallen to zero in that region, what is holding your compass pointing along the East - West line?  Move the magnet away from the compass.  Does the compass now return to aligning to the North-South line?  What can we conclude from the fact that the compass aligns to magnet axis that is perpendicular to the earth's magnetic North-South line even smack in the middle of the magnet where you contend the field strength has fallen to zero?

I already answered that question,and you either didnt read my reply,or once gain you are trying to push my buttons-so to speak.

Once again,which end of the compass needle would point to a region that has no magnetic field? The compass needles magnetic poles are simply being attracted to the opposite poles of the magnet-regardless of how far away each pole may be. I can get a compass needle to swing toward a magnets pole over a foot away-so once again,your experiment is nul and void.

Now ,are you going to take the time and draw those 3 diagrams i requested from you?. Do you have the time to do that,as you expect people like me to have the time to try different experiments for you.

[tinman]

I would also like to add that an electromagnets field shape is a little different due to the magnetic field produced around the conducting wire,and is more of a peanut shape-see pic bellow. Due to the magnetic field around the conducting wire,the field at the center of the magnets core(between each pole end) ,dose not completely fold back into the core.The region circled in green represents the strongest field concentration in an electromagnet,and is not confined within the core like a PM's field is at the same point.

Edit-the field shape line actually looks more black than blue,but it is the peanut/dog bone shapes line.

[MarkE]

I already answered that question,and you either didnt read my reply,or once gain you are trying to push my buttons-so to speak.

Once again,which end of the compass needle would point to a region that has no magnetic field? The compass needles magnetic poles are simply being attracted to the opposite poles of the magnet-regardless of how far away each pole may be. I can get a compass needle to swing toward a magnets pole over a foot away-so once again,your experiment is nul and void.

Now ,are you going to take the time and draw those 3 diagrams i requested from you?. Do you have the time to do that,as you expect people like me to have the time to try different experiments for you.

Tinman if the magnetic field were null at the dipole center as the Figure 8 claim requires then there would be nothing opposing the earth's magnetic field and the compass needle would align to the earth's field perpendicular to the dipole that is on the east-west line.  Try the experiment.  You will find that the conventional view prevails.