Iron filings that have oriented in the magnetic field produced by a bar magnet
Detecting magnetic field with compass & with iron filings
Main article: Magnetic field
The magnetic flux density (also called magnetic B field or just magnetic field, usually denoted B) is a vector field. The magnetic B field vector at a given point in space is specified by two properties:
Its direction, which is along the orientation of a compass needle.
Its magnitude (also called strength), which is proportional to how strongly the compass needle orients along that direction.
In SI units, the strength of the magnetic B field is given in teslas.
A magnet’s magnetic moment (also called magnetic dipole moment & usually denoted μ) is a vector that characterizes the magnet’s overall magnetic properties. For a bar magnet, the direction of the magnetic moment points from the magnet’s south pole to its north pole, & the magnitude relates to how strong & how far apart these poles are. In SI units, the magnetic moment is specified in terms of A·m2 (amperes times meters squared).
A Magnet for sale both produces its own magnetic field & responds to magnetic fields. The strength of the magnetic field it produces is at all given point proportional to the magnitude of its magnetic moment. In addition, when the Magnet for sale is put into an external magnetic field, produced by a different source, it is subject to a torque tending to orient the magnetic moment parallel to the field. The amount of this torque is proportional both to the magnetic moment & the external field. A Magnet for sale may also be subject to a force driving it in one direction or another, according to the positions & orientations of the Magnet for sale & source. If the field is uniform in space, the Magnet for sale is subject to no net force, although it is subject to a torque.
A wire in the shape of a circle with area A & carrying current I has a magnetic moment of magnitude equal to IA.
Main article: Magnetization
neodymium gold plated magnets Neodymium magnets appear in products such as microphones, professional loudspeakers, in-ear headphones, guitar and bass guitar pick-ups, and computer hard disks where low mass, small volume, or strong magnetic fields are required. Neodymium
neodymium magnets Neodymium magnets appear in products such as microphones, professional loudspeakers, in-ear headphones, guitar and bass guitar pick-ups, and computer hard disks where low mass, small volume, or strong magnetic fields are required. Neodymium
neodymium ring magnet Neodymium magnets (actually an alloy, Nd2Fe14B) are the strongest permanent magnets known. A neodymium magnet of a few grams can lift a thousand times its own weight. These magnets are cheaper, lighter, and stronger than samarium–cobalt magnets.
“neodymium ring magnets Here are some of the magnet manufacturers names you should look for:Always read the reviews of the specific magnet before making a purchase to see how others have rated it.
neodymium sphere magnets Certain transparent materials with a small concentration of neodymium ions can be used in lasers as gain media for infrared wavelengths (1054–1064 nm), e.g. Nd:YAG
small magnets Neodymium glass solid-state lasers are used in extremely high power (terawatt scale), high energy (megajoules) multiple beam systems for inertial confinement fusion. Nd:glass lasers are usually frequency tripled to the third harmonic at 351 nm in laser fusion devices.
sphere magnets Neodymium magnets appear in products such as microphones, professional loudspeakers, in-ear headphones, guitar and bass guitar pick-ups, and computer hard disks where low mass, small volume, or strong magnetic fields are required. Neodymium
super magnet modeling on how density, temperature, and pressure interact inside warheads. HELEN can create plasmas of around 106 K, from which opacity and transmission of radiation are measured.
The magnetization of a magnetized material is the local value of its magnetic moment per unit volume, usually denoted M, with units A/m. It is a vector field, rather than just a vector (like the magnetic moment), because different areas in a Magnet for sale can be magnetized with different directions & strengths (for example, because of domains, see below). A good bar Magnet for sale may have a magnetic moment of magnitude 0.1 A•m2 & a volume of 1 cm3, or 1×10−6 m3, & therefore an average magnetization magnitude is 100,000 A/m. Iron can have a magnetization of around a million amperes per meter. Such a large value explains why iron magnets are so effective at producing magnetic fields.
Two different models exist for magnets: magnetic poles & atomic currents.