Tesla (unit) One tesla is equivalent to: One tesla is equal to 1 V·s/m. This can be shown by starting with the speed of light in vacuum, "c" = (εμ), and inserting the SI values and units for "c" (), the vacuum permittivity ε (), and the vacuum permeability μ (). Cancellation of numbers and units then produces this relation. For the relation to the units of the magnetising field (ampere per metre or Oersted), see the article on permeability. Tesla (unit) The tesla (symbol T) is a derived unit of the magnetic field strength (also, magnetic flux density) in the International
Spectral flux density a collimated beam, while spectral flux density is suitable for that purpose. At a point within a collimated beam, the spectral flux density vector has a value equal to the Poynting vector, a quantity defined in the classical Maxwell theory of electromagnetic radiation. Sometimes it is more convenient to display graphical spectra with vertical axes that show the relative spectral flux density. In this case, the spectral flux density at a given wavelength is expressed as a fraction of some arbitrarily chosen reference value. Relative spectral flux densities are expressed as pure numbers without any units. Spectra showing the relative