What is the difference between B and H fields (magnetic fields ) of a material? Please explain a littleThanks in advance!
The H field corresponds to what is called the magnetic field strength. It is measured in amps / meter (A/m). That is to say it is caused by a current and exists in the space around the current independent of the material occupying the space. H will generally be stronger near to the current and will diminish in strength with distance from the current. In free space or in air the B field represents magnetic flux density which is given in units of Tesla by B μ?.H where μ? is the absolute magnetic permeability of free space and 4π10^-7. More magnetic flux can be produced by the same H value in certain (magnetic) materials, notably iron, and this is accounted by introducing another factor, the relative permeability μr, giving B μ?.μr.H for magnetic materials. μr can take values of over 1000 which makes iron very attractive to use in devices (like transformers) which employ magnetic fields. Without using iron such devices would be physically much larger.
