Ewing's Molecular theory of Magnetism - Science

This is a science video for grade 8-9 students that talks about Molecular Theory of magnestism proposed by Ewing which states that every molecule of a magnetic substance behaves as a tiny magnet called molecular magnet.

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[Phantasmzero]

Note taken: To turn an iron bar into a magnet; stroke it lovingly.

[megamarsvin]

It's not the most important thing in the world but I have to say I've never heard the name pronounced as E-wing before. Sounds very strange ^^

[hznfrst]

It's standard practice to give complete names when referring to scientists. In this case they are Wilhelm Weber (German, pronounced Vil-helm Vay-bear) and Alfred Ewing (Scots, pronounced You-wing). You should also use "north and south" instead of "n and s" for the magnetic poles.

[Streety101101]

interesting.... but the government dose not care until you can turn it into a weapon. 

[Alanofoxy]

vee-ber

and

you-wing

that is all.

[DrGoodwrench64]

....Cont

either reversing the coil windings (so the current flow continues in the same direction but the magnetic field is reversed) or by repositioning the screwdriver tip 180 degrees (tip to handle) and collapsing the magnetic field again.

Either way will result in the screwdriver being DE-magnetized.

*

Now, whoever made this video should not teach. This video is full of out-dated and incorrect data. Teaching these misconceptions will insure your students fail when applied in real world.

[DrGoodwrench64]

....Cont

striking one end of, lets say, an Iron or Steel rod or Bar. This is due to sudden molecular redistribution and alignment. While this technique does create a magnet, it is a very weak magnet at best. Rubbing a magnets North or South pole along a steel rod (like a screwdriver's shaft) will magnetize the shaft, it's only a temporary effect. But collapsing a magnetic field around that screwdriver's steel shaft will create a strong, permanent magnet. You can also DE-magnetize it by

Cont....

[DrGoodwrench64]

....Cont

Aurora Borealis of the North and South poles. The North pole pushes material out of our atmosphere into space like an exhaust port while at the same time the South pole acts like a magnetic intake for new material. This new material is pulled out of the Solar Wind and from Coronal Mass Ejections (CMEs) from our sun. Hence the reason the Earth stays the same size and mass and does not grow or shrink.

Also, you CAN create a permanent magnetic field in Iron and Steel by

Cont....

[DrGoodwrench64]

....Cont

At the Physical level, the relative magnetic density (aka - Flux Density) of a magnet is NOT equal at both ends. Magnets have a very slight but measurable difference between the N (North) and S (South) poles. The North pole has a slightly higher magnetic "Push" effect than the South pole. Conversely, the South pole has a slightly higher "Pull" effect than does the North pole. This can be observed readily in the Earth's magnetic field motion by comparing the

Cont....