Physics/Magnetic Questions

[hibob12345]

I need a physics expert to interview on the topic of magnetism. Can an expert please answer the following questions...

1. What interests you in the topic of magnetism?
2. When did you first study magnetism?
3. Why is magnetism important?
4. How is magnetism used in our everyday life?
5. What variables affect the strength of magnetism?
6. What makes a magnet magnetic?
7. When is magnetism usually used?
8. Can a magnet become de-magnetized?

Please respond back

Thanks in advance,

[deleted-71709]

Dear hibob12345

Being as nearly all your questions are technical ones, and not ones dealing with my own experience with magnets and magnetism, I'm going to refer you to some research first.

Here on Science Buddies you can find a lot of information about magnets and magnetism. Try these links:

https://www.sciencebuddies.org/science- ... p020.shtml
https://www.sciencebuddies.org/science- ... p025.shtml
https://www.sciencebuddies.org/mentorin ... p035.shtml

These will teach you a lot about magnets. You might also try these sites:

http://www.coolmagnetman.com/magindex.htm
http://en.wikipedia.org/wiki/Magnet

If you till have questions that you can't find in these resources, put another post on this site, let us know your specific question, and we'll get you some answers.

Ed Neu
Buffalo, MN

[hibob12345]

I'm sorry but I need a interview sorry about that. I meant to say that in the previous question. Sorry about that

[deleted-37163]

Hibob,

Sorry for the delay, but as you probably know ScienceBuddies was down for the weekend.

My name is Manjinder Kandola and I'm a high school student taking advanced physics courses. I'm not exactly an expert, but seeing as how you need an interview asap, I'll try my best to help you. Please make sure to also review edneu's post.

1. Regarding magnetism, I think the fact that electrons can align themselves to certain magnetic fields and thus impart a force on the object is very cool. Normally, gravity is the first force that comes to mind, but gravity is in fact the weakest of the four fundamental forces.

2. I played with magnets as a kid but I didn't really learn about their properties and the science behind them until high school in a physics class.

3-4, 7. (I think the three are related) Magnets are extremely important because of how widely they can be used in everyday life. TV's, computers, and other LED sources rely on magnetic fields to guide electrons to viewing screens. That's why your teachers tell you never to bring a strong magnet close to your computer, it may damage the magnetic field. Furthermore, common generators use magnets to convert energy from natural sources to electricity.

5. The strength of magnetism (given in tesla) varies greatly depending on the nature of the object. Magnetic substances can be labelled ferromagnetic, paramagnetic, and diamagnetic (see http://en.wikipedia.org/wiki/Magnet#Com ... of_magnets), which are written in decreasing order of strength. Factors that determine strength include the number of valence electrons, the method by which it was magnetized, how close the object is to the magnet, how the atomic structure of the magnet is likely to rearrange itself etc.

6. Magnets are magnetic because they have a magnetic field which ranges from its two poles. Essentially, the inside of a magnet is broken up into domains in which all the electrons have identical spins.

8. Yes, a magnet can become demagnetized. Here's what the Wiki link has to say:

"Magnetized materials can be demagnetized in the following ways:

Heating a magnet past its Curie temperature; the molecular motion destroys the alignment of the magnetic domains. This always removes all magnetization.
Hammering or jarring: the mechanical disturbance tends to randomize the magnetic domains. Will leave some residual magnetization.
Placing the magnet in an alternating magnetic field with an intensity above the materials coercivity and then either slowly drawing the magnet out or slowly decreasing the magnetic field to zero. This is the principle used in commercial demagnetizers to demagnetize tools and erase credit cards and hard disks, and degaussing coils used to demagnetize CRTs."

Hope that helps,

Manjinder