The past magnetic field is recorded mostly by strongly magnetic minerals, particularly iron oxides such as magnetite, that can carry a permanent magnetic moment.
12.
Permanent magnet brakes have a very high torque for their size, but also require a constant current control to offset the permanent magnetic field.
13.
One way to achieve this is to condition the shaft or a member attached to the shaft with a series of permanent magnetic domains.
14.
Complicating the analysis is that Ganymede, unlike Europa and Callisto, still possesses a molten core that generates its own permanent magnetic field similar to Earth's.
15.
The coil rotates in a permanent magnetic field and is restrained by fine spiral springs which also serve to carry current into the moving coil.
16.
Spin-particles can have a permanent magnetic moment along the direction of their spin, and this magnetic moment gives rise to electromagnetic interactions that depend on the spin.
17.
They have two causes : electromagnetic induction by the time-varying, external-origin geomagnetic field and motion of conducting bodies ( such as seawater ) across the Earth's permanent magnetic field.
18.
The mere demagnetization is to be distinguished from that with which the permanent magnetic orientation of a metal hulk can be lifted with a strong magnetic field for some time.
19.
The solid inner core is too hot to hold a permanent magnetic field ( see Curie temperature ) but probably acts to stabilize the magnetic field generated by the liquid outer core.
20.
This link is to the Permanent Magnetic Pump ( PMP ), but the data sheet also mentions an Electromagnetic Pump ( EMP ) .-- talk ) 18 : 35, 17 May 2012 ( UTC)
