REVIEW QUESTIONS
ON THE SUBJECT OF TELEPHONY
Pages 271—320

  1. What is a private-branch exchange?
  2. What does "P. B. X." mean?
  3. What is the function of the private-branch exchange operator?
  4. Describe the key type of a small private-branch exchange switchboard.
  5. Describe the different methods of supervision of private-branch connections.
  6. Describe the automatic equipment of the common-battery type in private-branch exchanges.
  7. How is secrecy of individual lines obtained in a private-exchange equipment?
  8. What is an intercommunicating system?
  9. Sketch a magneto intercommunicating system.
  10. Sketch and describe a plug type common-battery intercommunicating system.
  11. Sketch and describe the action of the push button in the Monarch system and in the Western Electric system.
  12. Sketch and describe the Monarch intercommunicating system.
  13. What is the office of the junction box in this system?
  14. What is a long-distance message?
  15. What is the function of the repeating coil in the long-distance line?
  16. Which is the simplest form of long-distance switch?
  17. What is a phantom circuit?
  18. Under what control is the ringing of the subscriber in long-distance calls?
  19. What is meant by ticket passing?
  20. What particular advantage has a common-battery set on long-distance lines?
  21. Give a typical load curve for telephone traffic.
  22. Why is traffic a study of importance?
  23. State the function of the intermediate distributing frame.
  24. State the different methods of traffic study.
  25. What is the trunking factor?
  26. Define trunking efficiency.
  27. Enumerate some of the elements upon which the quality of service in a manual system depends.
  28. What is team work?
  29. How does the cost of telephone service vary?
  30. What two general methods of charging for telephone service are in use?
  31. Describe a calculagraph and how is it used?
  32. How are toll connections timed by the Monarch Telephone Company?
  33. Sketch and describe the Western Electric Company line circuit and service meter.

REVIEW QUESTIONS
ON THE SUBJECT OF TELEPHONY
Pages 321—358

  1. Describe a phantom circuit with diagram.
  2. Explain how two phantoms may be joined by a physical circuit.
  3. Which are the better, phantom or physical circuits, and why?
  4. Explain how the simplex circuit differs from the phantom telephone circuit.
  5. Why are not telegraph wires as serviceable for telephone work as telephone wires are for telegraph work?
  6. Give the names of the different parts of a railway composite set and explain method of operating.
  7. State the causes of the introduction of the telephone into the train dispatching field and explain the advantages it has over the telegraph for this work.
  8. In transmitting orders for train dispatching, how are mistakes avoided?
  9. Describe the Western Electric selector and explain its use.
  10. In what way does the Gill selector differ from the Western Electric?
  11. What special feature does the multiple coil selector possess?
  12. What special arrangement is provided for the train dispatcher in noisy locations?
  13. How can a man on a wrecking train get connection with the train dispatcher?
  14. What is the usual limit in length of a telephone train dispatching circuit and what is the largest number of stations at present existing on such a circuit?
  15. What is the voltage of the sending battery for a train dispatcher's circuit and upon what is it dependent?
  16. For what purpose is a repeater circuit used?
  17. How is the noise caused by a high voltage battery absorbed so that the dispatcher may talk and signal simultaneously?
  18. Draw a diagram showing the circuit arrangement for the dispatcher's outfit of the Gill system.
  19. Explain fully the purpose of the retardation coil in connection with a waystation set.
  20. In case of accident to a train wire between two stations, how can the connection be patched if the road is also equipped with a message circuit in addition to the train wire?
  21. Why do some railroads have block wires in addition to train wires and message circuits?
  22. If a waystation on a block wire is to be cut out for any length of time, by what method can the two adjacent blocks be connected, eliminating the station between?
  23. What are some of the methods used for dispatching on electric railways where the traffic is not especially heavy?
  24. On an electric road in case a car approaches a semaphore set at "danger," what must the crew of the car do?