![Magnetic viewing film](https://upload.wikimedia.org/wikipedia/commons/c/c2/Magnetic_viewing_film.jpg)
Magnetic field viewing film is used to show stationary or (less often) slowly changing
magnetic fields
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...
; it shows their location and direction. It is a translucent thin flexible sheet, coated with micro-capsules containing nickel flakes suspended in oil.
When magnetic lines of force are parallel to the surface of the carrier sheet, the surfaces of the flakes are reflective, and appear bright. When lines of force are perpendicular to the sheet, the flakes are edge-on, and appear significantly darker. When the film is placed on a magnet's pole, the latter case applies.
Magnetic field viewing film together with a ruler can be used to measure the poles per inch of a magnet.
See also
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Ferrofluid
Ferrofluid is a liquid that is attracted to the poles of a magnet. It is a colloidal liquid made of nanoscale ferromagnetic or ferrimagnetic particles suspended in a carrier fluid (usually an organic solvent or water). Each magnetic particle ...
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Magna Doodle Magna Doodle is a Magnetism, magnetic drawing toy, consisting of a drawing board, a magnetic stylus, and a few magnet shapes. Invented in 1974 by Pilot Corporation, over forty million units have been sold to date worldwide, under several brands, pro ...
References
External links
Magnetic devices
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