WHAT CAN MAGNETS DO? 



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PROBLEM I. WHAT CAN MAGNETS DO? 



People have not always depended on lodestones for 

 magnets. It was discovered long ago that magnets could 

 be made out of 

 steel by rub- 

 bing the steel 

 with another 



Ar How will this change the properties of the knife blade? 



magnet. You 



can make a small magnet yourself. If you stroke a 

 needle from the middle to the point several times with 

 one end of a magnet and then, using the other end of 

 the magnet, stroke it from the middle to the opposite 

 end, you will make a magnet of the needle. You can 

 make a magnet of any piece of steel in the same way. 

 Large powerful magnets are made by passing a current 



of electricity through wires 

 which surround iron or steel 

 cores. 



What Will a Magnet At- 

 tract ? If we lay steel needles, 

 pins, tacks, gold pins, silver 

 pins, pure nickel, a nickel 

 coin, a copper coin, and a 

 brass key on the table and 

 move a bar magnet slowly 

 over them, will anything hap- 

 pen? What substances are 



the 



placed 

 near- all 

 objects 



n<le 

 iron nail 



What substances will a magnet pick 

 up? 



picked up ? We see as a re- 

 sult of this experiment that a 

 magnet will not pick up all metals. It has been found that 

 magnets will attract iron, steel, pure nickel, and cobalt, 

 but will not attract any other common substances. 



Permanent and Temporary Magnets. If you place a 

 powerful bar magnet over a dish of iron nails, you will 



