Lessons in practical electricity; principles, experiments, and arithmetical problems, an elementary text-book . Fig. 8.—Magnetisation by Divided Stroke. 8 PRACTICAL ELECTRICITY. to be magnetised, and a strong current of electricity passedthrough the coil from a battery or dynamo, as in Fig. 10, thesteel will be permanently magnetised with a N and S-pole,after the current is turned off. Tapping the end of the steelwith a hammer, while it is under the influence of the current,will produce better results. Instead of winding the wirearound the bar, the bar can be inserted in a spool containingmany
Lessons in practical electricity; principles, experiments, and arithmetical problems, an elementary text-book . Fig. 8.—Magnetisation by Divided Stroke. 8 PRACTICAL ELECTRICITY. to be magnetised, and a strong current of electricity passedthrough the coil from a battery or dynamo, as in Fig. 10, thesteel will be permanently magnetised with a N and S-pole,after the current is turned off. Tapping the end of the steelwith a hammer, while it is under the influence of the current,will produce better results. Instead of winding the wirearound the bar, the bar can be inserted in a spool containingmany turns of insulated wire (such as EM, Fig. 11, which canbe slipped off of its iron core) when a stronger magnet will. Fig. 10.—Magnetisation by an Electric Current. be obtained. In making a horseshoe magnet by thismethod insert one limb all the way in the spool; turn on thecurrent; tap it; turn off the current; remove this limb, andinsert the other limb in the opposite end of the coil andrepeat the operations. You will now have a magnet, thestrength of which, until the saturation point of the steel isreached, will depend on the current strength, and the numberof turns of wire on the spool. 15. Magnetisation by an Electromagnet.—A bar electro-magnet (i. e., the above spool and its iron core) may be sub-stituted for the permanent steel magnets used in the previousmethods for making a magnet, or two bar electromagnetsconnected by a piece of soft iron forming a horseshoe elec-tromagnet may be used (see Fig. 11.) In this case the cur-rent is passed through one spool in one direction, and thenthrough the other spool in the opposite direction, when the MAGNETISATION. 9 free ends of the core will have a
Size: 2069px × 1208px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1901
