Magnetic field flux density, units

To consider magnetic flux density components of IAIV, Q must have the units of weber and R, the scalar curvature, must have units of inverse square meters. In the flat spacetime limit, R 0, so it is clear that the non-Abelian part of the field tensor, Eq. (6), vanishes in special relativity. The complete field tensor F vanishes [1] in flat spacetime because the curvature tensor vanishes. These considerations refute the Maxwell-Heaviside theory, which is developed in flat spacetime, and show that 0(3) electrodynamics is a theory of conformally curved spacetime. Most generally, the Sachs theory is a closed field theory that, in principle, unifies all four fields gravitational, electromagnetic, weak, and strong. 

TESLA (T). A unit of magnetic flux density (magnetic induction). The magnetic flux density of a uniform field that produces a torque of 1 newton-meter on a plane current loop carrying 1 ampere and having a projected area of 1 square meter on the plane perpendicular to the field. T = N/A in. (The SI unit of magnetic flux density)... 

Table G Definitions of the Electric Field E, the (Di)electric Polarization P, the Electric Displacement D, the Magnetic Field H, the Magnetization M, the Magnetic induction or flux density B, statement of the Maxwell equations, and of the Lorentz Force Equation in Various Systems of Units rat. = rationalized (no 477-), unrat. = the explicit factor 477- is used in the definition of dielectric polarization and magnetization c = speed of light) (using SI values for e, me, h, c) [J.D. Jackson, Classical Electrodynamics, 3rd edition, Wiley, New York, 1999.]. For Hartree atomic u nits of mag netism, two conventions exist (1) the "Gauss" or wave convention, which requires that E and H have the same magnitude for electromagnetic waves in vacuo (2) the Lorentz convention, which derives the magnetic field from the Lorentz force equation the ratio between these two sets of units is the Sommerfeld fine-structure constant a = 1/137.0359895...

It is worth noting that the SI units of magnetic field strength, or more correctly magnetic flux density, are the Tesla, T, or millitesla, mT. However for historical reasons the older units of Gauss, G, are still commonly used, where lmT= lOG. 

Light beams are represented by electromagnetic waves that are described in a medium by four vector fields the electric field E r, t), the magnetic field H r, t), the electric displacement field D r,t), and B r,t) the magnetic induction field (or magnetic flux density). Throughout this chapter we will use bold symbols to denote vector quantities. All field vectors are functions of position and time. In a dielectric medium they satisfy a set of coupled partial differential equations known as Maxwell s equations. In the CGS system of units, they give... 

Since non-linear optics has been developed by both physicists and chemists, and by both theoreticians and experimentalists, there are, as might be expected, differences in names, abbreviations and definitions of the pertinent properties, as well as the use of different units. In this section I hope to both clarify and simplify the situation. Let us start with the usual expansion [3] of the change in energy of a species when it is subjected to a static uniform electric field (F) and a static uniform magnetic field (B) strictly speaking, B is the magnetic flux density. We can write ... 

Flux density the number of lines of force per unit area Lines of force the free path that would be traced by a unit pole in a magnetic field owing to the forces acting upon it is called the line of force. Consider a unit pole enclosed in a sphere that has a radius of 1.0 cm. For the unit pole, one line of force passes through each square cm of area, and since there are An cm of surface area on the sphere, there are 4 r lines of force emanating from each unit pole... 

Symbol p. The ratio of the magnetic flux density, B, in a substance to the external field strength, H i.e. p= B/H. The permeability of free space, po. is also called the magnetic constant and has the value 4it x 10" H m" in S1 units. The relative permeability of a substance, p is given by p/po and is therefore dimensionless. See magnetism. 

The number of lines of magnetic flux within a magnetic field is a measure of the flux density. Strong magnetic fields have a high-flux density. The symbol used for flux density is S, and the unit of flux density is the tesla (symbol T), to commemorate the work of the Croatian-born American physicist Nikola Tesla (1856-1943). 

---