Osnovno poznavanje magneta
The ancient Greeks and Chinese discovered a naturally magnetized stone in nature, which they called "magnetite". The stone can magically pick up small pieces of iron and always point in the same direction when swung at will. Early navigators used this magnet as their earliest compass to identify directions at sea. After thousands of years of development, today magnets have become a powerful material in our lives. By synthesizing alloys of different materials, the same effect as magnetite can be achieved, but the magnetic force can also be improved. Man-made magnets appeared in the 18th century, but the process of making stronger magnetic materials was slow until Alnico was made in the 1920s. Subsequently, ferrite (Ferrite) was produced in the 1950s, and rare earth magnets were produced in the 1970s Rare Earth magnets include neodymium iron boron (NdFeB) and samarium cobalt (SmCo). So far, magnetic technology has developed rapidly, and strong magnetic materials have also made components more miniaturized.
Koji je smjer magnetizacije (orijentacije)?
Most magnetic materials can be magnetized to saturation in the same direction, which is called the "magnetization direction" (orientation direction). Magnets with no orientation (also called isotropic magnets) are much weaker than oriented magnets (also called anisotropic magnets).
What is the standard industrial definition of "North and South Poles"?
The definition of "North Pole" is that after the magnet rotates at will, its north pole points to the earth's north pole. Likewise, the south pole of the magnet points to the south pole of the earth. How can I tell the north pole of a magnet without a label?
Obviously, it is impossible to tell with the eyes alone. The magnet can be approached with a compass, and a pointer pointing to the Earth's north pole will point to the magnet's south pole.
Kako bezbedno rukovati i čuvati magnete?
Uvijek budite vrlo oprezni jer će se magneti sami zalijepiti i mogu vam priklještiti prste. Kada se magneti međusobno privlače, moguće je i da se sami magneti oštete zbog sudara (izbijeni uglovi ili izbijene pukotine). Držite magnete dalje od predmeta koji se lako magnetiziraju, kao što su diskete, kreditne kartice, kompjuterski monitori, satovi, mobilni telefoni, medicinska oprema, itd. Magnete treba držati dalje od pejsmejkera.
Za magnete veće veličine, između svakog komada treba dodati plastične ili kartonske odstojnike kako bi se osiguralo da se magneti mogu lako odvojiti. Magnete treba čuvati u suvom okruženju sa konstantnom temperaturom što je više moguće.
Kako postići magnetnu izolaciju?
Samo materijal koji se može adsorbirati na magnet može igrati ulogu izolacije magnetnog polja, a što je materijal deblji, to je bolji učinak izolacije magnetnog polja. Koji je najjači magnet?
Trenutno, magneti sa najvećim performansama su magneti retkih zemalja, a među magnetima retkih zemalja, NdFeB je najjači magnet. Ali na temperaturama iznad 200 stepeni Celzijusa, samarijum kobalt je najjači magnet.
