An elementary book on electricity and magnetism and their applications . Fig. 52. — Effect of mag-net on flexible wire car-rying electric current. ELECTROMAGNETISM 95 to unwind and then rewind around the magnet in the reverse manner,thus again bringing the two magnetic fields into parallelism. Instead of the steel magnet, the fixed magnet in this experimentmay he a solenoid intensified by the introduction of an iron coil aroundwhich the coils are wound. Such a magnet may be caused to give avery powerful effect, and for that reason figure 52 shows such Iron Core 69. Electromagne
An elementary book on electricity and magnetism and their applications . Fig. 52. — Effect of mag-net on flexible wire car-rying electric current. ELECTROMAGNETISM 95 to unwind and then rewind around the magnet in the reverse manner,thus again bringing the two magnetic fields into parallelism. Instead of the steel magnet, the fixed magnet in this experimentmay he a solenoid intensified by the introduction of an iron coil aroundwhich the coils are wound. Such a magnet may be caused to give avery powerful effect, and for that reason figure 52 shows such Iron Core 69. Electromagnets. When a coil of wire (, a solenoid)is wound around a piece of soft iron or steel for the purpose ofgetting a magnetic field, the combinationis called an electromagnet. A piece of hardsteel might be usedinstead of soft iron,but in this case theamount of magnetismcreated by a givencurrent in the turns ofthe coil, or number ofampere turns, wouldbe much less than isproduced in soft iron ;moreover, the steelwould retain its mag-netism and become aso-called permanent magnet. Soft iron or mild steel is uni-versally used, therefore, in electromagnets, The electromagnet is of the greatest value in electricalindustries because it can be built in practically any desiredsize and form, and with enormous magnetic strength becauseits magnetism is under the control of the current: when thecircuit is made, it becomes a magnet; when the circuit is broken, it ceases to act as a magnet. The magnets ofcommercial dynamos and electric motors are always electro-magnets. Figur
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectmagnetism, bookyear19
