The hard drive uses two important principles about the magnetic fields. :: Computer Science

The big(p) drive uses two authorized principles virtually the magnetised ambits. When we create verbally data onto the thorny drive Cit uses the law of electromagnetic inductor and some material is magnetic.The hard drive uses two important principles about the magneticfields.When we economize data onto the hard drive it uses the law ofelectromagnetic induction and some material is magnetic.When we read data from the hard drive, it uses the Lenzs law.How hard disk drive worksFirstly we should know the two important part of the hard disk drive,1. platters and mediaWe put all of the data onto the platters. They argon inside of the harddrive. There be several pieces of platter in the hard disk drive,maybe three or four. They atomic number 18 make of special material. The materialmust be unbendable and light. Because there are high rotation rates, whenthe hard disk drive working. Traditionally, people frequently use aluminumbecause it is a light material. But today, most pl atters are made frommaterial like glass or ceramic composite. These light, strongmaterials have a very low thermal expansion, and compare to aluminum.They batch withstand higher forces. So the platters endure run faster.Older hard disk drive can only run at 3600 to 5200 rpm. Todays onescan run7600 to 10000 rpm.There is a point of magnetic material on the surface of the platters.Today a thin-film media is used here. Thin-film media is a microscopiclayer of pure metal bonded to the substrate surface through an interimlayer. Because the place between honcho and platters is very small(about 10 micro inches), yet they can not touch with each other. Sothe thin-film media is very smooth and is coated with a protective layerto help survive head crashing.2. the branch and read and write headThe arm that holds the read/write heads is controlled by the mechanismin the upper-left corner, and is able to move the heads from the hubto the edge of the drive. The arm and its movement mechani sm areextremely light and fast. The arm on a typical hard-disk drive canmove from hub to edge and spine up to 50 times per second. It is hardto believe. But it is the truth.Simply, The read and write head is a ferromagnetic core. It can carrefour a course magnetic fields through a variety current to be ableto write data onto the media in ASC2. And also can product varietycurrent though inducing the variety magnetic field on the surface ofthe platter to read data from the hard disk drive.