ELECTRIC HEATING DEVICES 



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Showing the resistance wires in an electric 

 stove. 



chafing dishes, heating pads, curling irons, even with water 

 and room heaters, and electric ranges. However, the electric 

 flat iron is by far the most popular electric device so far intro- 

 duced into the home . The 

 principle of electric heat- 

 ing is practically the same 

 in all of them. All con- 

 ductors resist the flow of 

 electricity. The electrical 

 energy used in overcoming 

 the resistance becomes 

 heat. Some metals, like 

 German silver and nich- 

 rome, offer much greater 

 resistance than copper does. For that reason a short 

 length of nichrome wire would give as much heat as a much 

 longer copper wire of the same diameter. It is advantageous 

 then to use a wire of very high resistance in heating de- 

 vices where the heat is produced by electricity. You re- 

 member when studying about electric lights how along wire 



was heated by an elec- 

 tric current. When 

 the wire is in position 

 in the base of a flat- 

 iron it is covered with 

 an enamel which is 

 baked on so that the 

 wire cannot move out 

 of position or touch 

 other parts of the wire. The heating element of the coffee 

 percolator and other devices is made essentially in the 

 same manner. The electric iron should have a switch 



Electric heating pad. 



