A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets.
A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism.
Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron, which can be magnetized but do not tend to stay magnetized, and magnetically "hard" materials, which do. Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferrite that are subjected to special processing in a strong magnetic field during manufacture to align their internal microcrystalline structure, making them very hard to demagnetize. To demagnetize a saturated magnet, a certain magnetic field must be applied, and this threshold depends on coercivity of the respective material. "Hard" materials have high coercivity, whereas "soft" materials have low coercivity. The overall strength of a magnet is measured by its magnetic moment or, alternatively, the total magnetic flux it produces. The local strength of magnetism in a material is measured by its magnetization.
An electromagnet is made from a coil of wire that acts as a magnet when an electric current passes through it but stops being a magnet when the current stops. Often, the coil is wrapped around a core of "soft" ferromagnetic material such as mild steel, which greatly enhances the magnetic field produced by the coil.
i'm sure some of you are familiar with a gauss rifle. I'm doing an experiment using the magnets and marbles. does this at all relate to the gauss rifle guns.thanks
an old 'newbie' with first post. excuse my physics knowledge it has been a long time since college.
>>>QUESTION below<<<
Magnets repel (each other).
If repelling 'each other' through a plane (ex. piece of glass) and water is allowed to flow over the plane.
WHAT will happen to the water when...
Hi,
Is it possible for two objects of nearly the exact same size, mass, and magnetic field strength to form something analogous to a curved space orbit in a relatively flat space by balancing inertia with magnetism? In other words, can two mutually magnetic objects orbit around a common center...
How do I figure out how much electricity would be generated by dropping a magnet down a coil of wire? What are the specific variables that would determine this? Is the number of coils more importants than the thickness of the wire and If it does generate electricity what's the best way to store...
Hey everyone, got a quickie for u. I'm not sure if there is a proper answer for this question, but could ppl give me brief theories to why superconductors repel magnets no matter what polarity they are. thanks for any input!
Check this site address out: http://scitoys/scitoys/scitoys/magnets/gauss.html
It is a neat little science project site, and I found this project the most interesting (except for the non-elecricity requiring radio) on their site. How it tells you it works(shortened): You take a ruler and...
ok, I'm on my cell so forgive the spelling :) This question will be in stages so no one posts all the answers at once and nobody else gets to have fun...
First Thing: let's explain How electricity is generated when sliding it through coils of wire. The equations would be very nice also, if...
DO NOT TRY THIS EXCEPT ON A JUNK
TV OR MONITOR
If you hold a strong permanent
magnet up to a T.V. screen while
it is on, the magnetic field
does some really intriguing
warping of the image. When you
take the magnet away the image
goes back to normal except that
the color is now patchy and in-...
I am building a little experiment to demonstrate the impact of metal objects. It consists of the following two configurations:
Magnets used are grade N38 NdFeB rare Earth magnets.
##RM## - Cylindrical magnet that is 1 1/2" long x 1/2" diameter laid lengthwise
CM - 1/2" cube magnet
B -...
http://www.wondermagnets.com/cgi-bin/edatcat/WMSstore.pl?user_action=detail&catalogno=3138
I'm thinking of getting some, I just purchased some neodymium magnets.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2545710646
My physics teacher gave the class a brief explanation of a permanent magnet. If I understood him correctly he basically said the special condition with a permanent magnet is that all the electrons are circling uniformly (in same direction). The poles of the magnet are based on the direction the...
A physics experiment with magnets and a vote pole-results
This is an experiment with magnets in motion.
The question is that if one magnet is spinning along a circular plane such that
the north end arrives at a point on the circle just as often as the south end, then what will happen if...