The amount of flux produced by the magnet indicates the strength of the magnet. The more the magnetizing force (MMF), the more is the flux produced. The more the opposition to the flux path (i.e., reluctance or magnetic resistance) less is the flux produced. This relationship is expressed as Flux = MMF/ Reluctance Reluctance is the opposition offered by the material in the flux path to the establishment of the flux. The reluctance in a magnetic circuit is similar to the resistance in an electric circuit. Reluctance is the inverse of permeance. MMF = Flux/Permeance
While estimating the overhead lines, the first and last pole is always earth connected and after every 3rd electrical pole, the fourth pole is earthed. Therefore, the approximate number of required ground set = 4
Magnetic Field Strength (H) gives the quantitative measure of strongness or weakness of the magnetic field. H = B/μo Where B = Magnetic Flux Density μo = Vacuum Permeability The magnetic Field strength at the center of circular loop carrying current I is given by B = μoI/2r B/μo = I/2r H = I/2r At/m Where r = Radius