224 APPLIED SCIENCE 



Questions 



1. How long has the telephone been used? 



2. Who invented the telephone? 



3. Explain the principle on which the telephone is based. 



4. Describe the steps in telephoning. 



5. Describe the construction of a switchboard. 



6. Who invented the telegraph? 



7. Describe a telegraph instrument. 



8. Describe a telegraph system. 



9. Explain the steps in telegraphing. 



10. State some of the advantages of the telephone and telegraph. 



