180 ELECTRICITY AND MAGNETISM 



6. Name all the advantages of tilling the soil and 

 tell how tilling may be accomplished. 



7. What is a machine? Of what use is a machine 

 to us? Name two simple machines and explain how they 

 help us. 



What are magnets? What are the two kinds of 

 magnets? What is meant by attraction? 



9. What are the poles of a magnet? How are the 

 poles of a magnet different from the rest of the magnet? 

 What are lines of force? 



10. What is a keeper and what is its use? What 

 is a magnetic field? W T hat is meant by repulsion? What 

 is induced magnetism? 



