Search results
Results from the WOW.Com Content Network
Contains one of the finest Pleistocene relict habitats in Missouri. Taberville Prairie Conservation Area: 1975: St. Clair: state One of the largest remaining virgin tall grass prairies. Tucker Prairie: 1975: Callaway: private A virgin tall grass prairie occurring within the transition zone between the oak-hickory forest and typical tall grass ...
Magnetic current density, which has the unit V/m 2 (volt per square meter), is usually represented by the symbols and . [a] The superscripts indicate total and impressed magnetic current density. [1] The impressed currents are the energy sources. In many useful cases, a distribution of electric charge can be mathematically replaced by an ...
Substitution gives the non-homogeneous Maxwell equations in potential form. Many different choices of A and φ are consistent with given observable electric and magnetic fields E and B, so the potentials seem to contain more, (classically) unobservable information. The non uniqueness of the potentials is well understood, however.
Breakdown of ideal MHD (in the form of magnetic reconnection) is known to be the likely cause of solar flares. The magnetic field in a solar active region over a sunspot can store energy that is released suddenly as a burst of motion, X-rays, and radiation when the main current sheet collapses, reconnecting the field. [31] [32]
While compass surveying, the magnetic needle is sometimes disturbed from its normal position under the influence of external attractive forces. Such a disturbing influence is called as local attraction. [1] The external forces are produced by sources of local attraction which may be current carrying wire (magnetic materials) or metal objects. [2]
> is the (volume) magnetic susceptibility, is the magnitude of the resulting magnetization (A/m), is the magnitude of the applied magnetic field (A/m), is absolute temperature , is a material-specific Curie constant (K).
Assuming the external magnetic field is uniform and shares a common axis with the paramagnet, the extensive parameter characterizing the magnetic state is , the magnetic dipole moment of the system. The fundamental thermodynamic relation describing the system will then be of the form U = U ( S , V , I , N ) {\displaystyle U=U(S,V,I,N)} .
When a magnetic field is approximated as force-free, all non-magnetic forces are neglected and the Lorentz force vanishes. For non-magnetic forces to be neglected, it is assumed that the ratio of the plasma pressure to the magnetic pressure —the plasma β —is much less than one, i.e., β ≪ 1 {\displaystyle \beta \ll 1} .