Electricity for public schools and colleges . plane. Note.—Field due to an electro-magnet.— calculating the fielddue to an electro-magnet we canconsider the solenoid, and the corewhich has become a cylindrical magnet, separately. But in general the field due to the former is relatively insignificant, and we need only regard the core. § 12. Paramagnetic and Diamagnetio Phenomena.—Whenpowerful electro-magnets are employed it is found that all bodiesare influenced by the magnetic field {see § 6). If pellets of various materials are suspended, by means of alight and long thread, near one of the po
Electricity for public schools and colleges . plane. Note.—Field due to an electro-magnet.— calculating the fielddue to an electro-magnet we canconsider the solenoid, and the corewhich has become a cylindrical magnet, separately. But in general the field due to the former is relatively insignificant, and we need only regard the core. § 12. Paramagnetic and Diamagnetio Phenomena.—Whenpowerful electro-magnets are employed it is found that all bodiesare influenced by the magnetic field {see § 6). If pellets of various materials are suspended, by means of alight and long thread, near one of the poles of such a magnet, itis found that certain substances are attracted by the pole, whileothers are repelled. Those bodies which are attracted are c^Wtd. paramagnetic, ormagnetic; such are iron, nickel, cobalt, manganese, platinum,carbon, many salts of magnetic metals, solutions of such salts, andoxygen gas. Those bodies which are repelled are called diamagjietic; suchare bismuth, antimony, zinc, tin, mercury, lead, silver, copper,. CH. XX. SOLENOIDS AND ELECTRO-MAGNETS 335 gold, phosphorus, glass, quartz, alum, sulphur, sugar, hydrogen,nitrogen, water, alcohol, and most other lic^uids and gases nothere named. Iron is the most strongly magnetic, and bismuth the moststrongly diamagnetic, body known. If we make bars of various substances, those which are mag-netic will set axially, or in a line with the poles ; while thosewhich are diamagnetic will set equatorially, or at right angles tothe line joining the poles (see § 9). The accompanying figure represents experiments with magneticand diamagnetic liquids respectively, The liquid is placed in awatch-glass and rests on the poles. Whenthe current is passed, the magnetic liquidB rises up in a heap over each of thetwo poles ; while the diamagnetic liquidA is repelled into a heap between thetwo poles. Such effects are very small,and must be magnified by means of re-flected light if they are to be made difference be
Size: 1227px × 2035px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpubl, booksubjectelectricity
