Open AccessOn the field of force near the neutral point produced by two equal coaxial coils, with special reference to the Campbell standard of mutual inductance
Author(s) -
Raymond M. Wilmotte
Publication year - 1925
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1925.0051
Subject(s) - inductance , coaxial , radius , plane (geometry) , physics , magnetic field , point (geometry) , field (mathematics) , turn (biochemistry) , electrical engineering , geometry , mathematics , mathematical analysis , nuclear magnetic resonance , engineering , computer science , voltage , quantum mechanics , computer security , pure mathematics
When a current is passed through two equal coaxial coils so that the component of the magnetic fields parallel to the common axis add, there is a circle, mid-way between the two coils, at which the magnetic field is zero. At all points in the plane of that circle lying outside it, the field of force is in one direction, and at all points within the circle it is in the opposite direction. It is evident, therefore, that if a coaxial turn of wire be placed in the plane of the circle, the mutual inductance between the two coils will be a maximum, when the wire coincides with the circle, and any small change in the radius of the turn will affect the value of the mutual inductance only to the second order of small quantities.