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This article is about objects and devices that produce magnetic fields. For a description of magnetic materials, see magnetism. For other uses, see Magnet (disambiguation).
Iron filings that have oriented in the magnetic field produced by a bar magnet
Magnetic field lines of a solenoid which are similar to a bar magnet as illustrated above with the iron filingsA magnet (from Greek μαγνήτις λίθος magnḗtis líthos, "Magnesian stone") 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 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 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 iron, nickel, cobalt, some rare earth metals and some of their alloys (e.g. Alnico), 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.
Some ferromagnetic materials can be magnetised by a magnetic field but do not tend to remain magnetised when the field is removed; these are termed soft. Permanent magnets are made from magnetically hard ferromagnetic materials that stay magnetized. permanentmagnets net/
An electromagnet is made from a coil of wire which acts as a magnet when an electric current passes through it, but stops being a magnet when the current stops. Often an electromagnet is wrapped around a core of ferromagnetic material like steel, which enhances the magnetic field produced by the coil.
The overall strength of a magnet is measured by its magnetic moment, while the local strength of the magnetism in a material is measured by its magnetization.
Luggage is any number of bags, cases and containers which hold a traveller's articles during transit. The modern traveller can be expected to have packages containing clothing, toiletries, small possessions, trip necessities, and on the return-trip, souvenirs. For some, luggage and the style thereof is representative of the owner's wealth.
Luggage - 1596, from lug (v.) "to drag;" so, lit. "what has to be lugged about" (or, in Johnson's definition, "any thing of more bulk than value"). In 20c., the usual word for "baggage belonging to passengers."
Baggage can be synonymous with "luggage", or can refer to the train of people and goods, both military and of a personal nature, which commonly followed pre-modern armies on campaign. The baggage was considered a strategic resource and closely guarded. Its loss was considered to weaken and demoralize an army, leading to rearguard attacks such as that at the Battle of Agincourt.
Luggage has changed over time. Historically the most common types of luggage were chests or trunks made of wood or other heavy materials. These would be shipped by professional movers. Since the Second World War smaller and more lightweight suitcases and bags that can be carried by an individual have become the main form of luggage. luggagesets com cn
With more and more passengers travelling by air the baggage handlers have seen an increase of passengers using the airline transport industry's ATA 300 Specifications for baggage designs acceptable for air transport, including both 'hand luggage' and 'hold luggage'.
Flexible materials can be bent, twisted, coiled, punched, and otherwise machined into almost any shape without loss of magnetic energy.
Higher energy flexible materials may sometimes replace Ceramic 1 materials, if close tolerances are not required, and if operating temperatures are below about 250F. Standard grades of flexible materials have energy products from 0.6 MGOe to 1.6 MGOe.
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