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Magnetic levitation can be stabilised using different techniques; here rotation (spin) is used. Magnetic levitation (maglev) or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields. Magnetic force is used to counteract the effects of the gravitational force and any other forces. [2]
Quadrupole magnets are useful as they create a magnetic field whose magnitude grows rapidly with the radial distance from its longitudinal axis. This is used in particle beam focusing. The simplest magnetic quadrupole is two identical bar magnets parallel to each other such that the north pole of one is next to the south of the other and vice ...
The magnetic pole model assumes that the magnetic forces between magnets are due to magnetic charges near the poles. This model works even close to the magnet when the magnetic field becomes more complicated, and more dependent on the detailed shape and magnetization of the magnet than just the magnetic dipole contribution.
Alnico alloys can be magnetised to produce strong magnetic fields and have a high coercivity (resistance to demagnetization), thus making strong permanent magnets. Of the more commonly available magnets, only rare-earth magnets such as neodymium and samarium-cobalt are stronger.
For an electromagnet with a cylindrical bore, producing a pure multipole field of order , the stored magnetic energy is: =!. Here, is the permeability of free space, is the effective length of the magnet (the length of the magnet, including the fringing fields), is the number of turns in one of the coils (such that the entire device has turns), and is the current flowing in the coils.
This magnetic orientation process replicates that applied by a magnetic recording tape head to the magnetic tape coating during the recording process. The principle was further described by James (Jim) M. Winey of Magnepan in 1970, for the ideal case of continuously rotating magnetization, induced by a one-sided stripe-shaped coil.
The rotating magnetic field is the key principle in the operation of induction machines.The induction motor consists of a stator and rotor.In the stator a group of fixed windings are so arranged that a two phase current, for example, produces a magnetic field which rotates at an angular velocity determined by the frequency of the alternating current.
If we rotate one of the hard magnets (north pole point down), the iron U on top will see a north pole and a south pole. The other iron U will see exactly the opposite. In this way almost all the magnetic flux will be concentrated inside both iron U's creating a close circuit for the magnetic field (because the high permeability of the iron).