ines? (_b_) Trunk lines? (_c_) Toll
lines?

3. For what purpose is the switchboard?

4. Give short descriptions of the different classes of switchboards.

5. How are manual switchboards subdivided? Describe briefly the
different types.

6. Define A and B boards.

7. What is a call circuit?

8. What kind of calls are handled on a toll switchboard?

9. Give drop symbol and describe its principles.

10. What is a jack?

11. Make a sketch of a plug inserted into a jack.

12. Give jack and plug symbols.

13. What are ringing and listening keys?

14. Show symbols for ringing and listening keys.

15. State the parts of which a cord equipment consists.

16. Show step by step the various operations of a telephone system
wherein the lines center in a magneto switchboard. Make all the
necessary diagrams and give brief descriptions to show that you
understand each operation.

17. On what principle does a drop with night-alarm contact operate?

18. What is the advantage of associating jacks and drops?

19. Describe the mechanical restoration as employed in the Miller
drop and jack.

20. Describe the electrical restoration of drop shutters as
manufactured by the Western Electric Company.

21. What complications arise in ringing of party lines and how are
they overcome?

22. Give diagram of the complete circuit of a simple magneto
switchboard.

23. Sketch night-alarm circuit with relay.

24. What is a convertible cord circuit?

25. State what disadvantages may be encountered under certain
conditions with a bridging drop-cord circuit.

26. Are lamps in cord circuits to be advocated on magneto
switchboards?

27. What is the function of the cabinet?

28. Give cross-section of upright switchboard as used in the magneto
system.

29. What is the purpose of a sectional switchboard?

30. Give a short description of the essential parts of a sectional
switchboard.

INDEX

INDEX

_The page numbers of this volume will be found at the bottom of the
pages; the numbers at the top refer only to the section._

A

Acousticon transmitter
Acoustics
characteristics of sound
loudness
pitch
timbre
human ear
human voice
propagation of sound
Air-gap vs. fuse arresters
Amalgamated zincs
Arrester separators
Audible signals
magneto bell
telegraph sounder
telephone receiver
vibrating bell
Automatic Electric Company
direct-current