Similarly, if only the magnetic field ( "'B "') is non-zero and is constant in time, the field is said to be a magnetostatic field.
12.
These equations are the time-dependent generalization of Coulomb's law and the Biot Savart law to electrodynamics, which were originally true only for electrostatic and magnetostatic fields, and steady currents.
13.
In a magnetostatic situation, the magnetic field "'B "'as calculated from the Biot Savart law will always satisfy Gauss's law for magnetism and Amp�re's law:
14.
In the case the fields are time-independent ( electrostatic and magnetostatic fields ), the time derivatives in the \ Box operators of the fields are zero, and Maxwell's equations reduce to
15.
These domains, called " flux closure domains ", allow the field lines to turn 180?within the material, forming closed loops entirely within the material, reducing the magnetostatic energy to zero.
16.
The first term can be treated as a magnetostatic pressure, while the second is important only if there is a spatial gradient of the fluid susceptibility, e . g ., in a non-isothermal system.
17.
So flux closure domains will only form where the magnetostatic energy saved is greater than the sum of the " exchange energy " to create the domain wall, the magnetocrystalline anisotropy energy, and the magnetoelastic anisotropy energy.
18.
:: : : I tried to translate Japanese text; they seem to be big-sized conventional speakers rather than magnetostatic or electrostatic ones .-- talk ) 22 : 27, 8 April 2015 ( UTC)
19.
:If you would like to know about how these " planar " speakers work we have two articles : Magnetostatic loudspeaker & Electrostatic loudspeaker .-- talk ) 21 : 57, 7 April 2015 ( UTC)
20.
An additional way for the material to further reduce its magnetostatic energy is to form domains with magnetization at right angles to the other domains " ( diagram c, right ) ", instead of just in opposing parallel directions.
