Review Questions

1. Distinguish between the terms central office and telephone exchange.

2. Distinguish between the terms telephone set and telephone station.

3. From the standpoint of the location of the battery, how may telephone systems be classified?

4. From the standpoint of the method of switching, how may telephone systems be classified?

5. Why is a capacitor sometimes used as indicated in Fig. 3?

6. What is the difference between a sidetone-reduction circuit and an anti-sidetone circuit?

7. What two principles are used in antisidetone circuits?

8. Discuss the methods used for making line connections in common-battery systems.

9. Describe a typical subscriber line. About what would be the resistance of a typical subscriber line, or loop?

10. In a common battery system, when a "B" operator starts to plug in on a called line, how does she know if the line is busy?

11. What is meant by a cord circuit, and what equipment does it contain?

12. Explain the principle of tandem trunking.

13. What types of dial systems are used in the United States?

14. Discuss the functions of the shunt springs in the dial.

15. About what is the normal speed of a telephone dial? Why not speed it up, so that dialing can be faster?

16. What is an important difference in the operation of a selector switch and a connector switch?

17. In the step-by-step system, what devices are used to interconnect the central-office equipment and the calling subscriber line?

18. What is the bank assembly in a step-by-step system? A wiper?

19. What major functions are performed by a selector switch? By a connector switch?

20. Name several uses for step-by-step connectors outside of telephone systems.

21. What is accomplished by reverting call equipment?

22. What is a typical field of application of an all-relay system? What major pieces of equipment are used?

23. What is a fundamental difference between the step-by-step system and the panel and rotary systems?

24. What is a fundamental difference between the step-by-step system and the crossbar system?

25. What types of dial systems involve the extensive use of sliding contacts to switch the circuits? What type of contact is used in the crossbar system?

26. Describe the operation of a crossbar switch.

27. What switching frames are used in a crossbar system?

28. What types of switches are on each crossbar frame?

29. What is the difference between a link and a junctor?

30. Enumerate the stages involved in the progress of a call through a crossbar system.