Expression for the flux within a certain wavelength range
Answers
Faraday's Law states that the voltage induced in a single turn of wire wrapped around a magnetic core is equal to the rate of change of the magnetic flux enclosed by that wire. One of Maxwell's equations (generalizing Faraday's Law) asserts that the line integral of the Dot Product of the induced voltage vector and the differential path vector along a single turn of wire wrapped around a magnetic core equals the surface integral of the Dot Product of the rate of change of a magnetic flux density vector within that turn of wire and a differential surface integrated over the area enclosed by that wire. This version of the law applies for stationary surfaces. This is sufficiently complicated to make many engineers look for an alternate career path.