Flux surface surrounding a charge "q" is "q"/ε. In free space the electric displacement is given by the constitutive relation D = ε E, so for any bounding surface the D-field flux equals the charge "Q" within it. Here the expression "flux of" indicates a mathematical operation and, as can be seen, the result is not necessarily a "flow", since nothing actually flows along electric field lines. The magnetic flux density (magnetic field) having the unit Wb/m (Tesla) is denoted by B, and magnetic flux is defined analogously: with the same notation above. The quantity arises in Faraday's law of induction,
Steinmetz's equation made. An improved generalized Steinmetz equation, often referred to as iGSE, can be expressed as where formula_13 is the flux density from peak to peak and formula_14 is defined by Steinmetz's equation Steinmetz's equation, sometimes called the power equation, is an empirical equation used to calculate the total power loss (core losses) per unit volume in magnetic materials when subjected to external sinusoidally varying magnetic flux. The equation is named after Charles Steinmetz, a German-American electrical engineer, who proposed a similar equation without the frequency dependency in 1890. The equation is: where "P" is the time average power loss per