REVIEW QUESTIONS

ON THE SUBJECT OF TELEPHONY

PAGES 63—­141

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1.  On what general principle are most of the telephone transmitters of today constructed?

2.  Make sketch of the new Western Electric transmitter and describe its working.

3.  Make sketch and describe the Kellogg transmitter.

4.  What troubles were encountered in the earlier forms of granular carbon transmitters and how were they overcome?

5.  What limits the current-carrying capacity of the transmitter?  How may this capacity be increased?

6.  State in what kind of transmitters a maximum degree of sensitiveness is desirable.

7.  Show the conventional symbols for transmitters.

8.  Describe a telephone receiver.

9.  Sketch a Western Electric receiver and point out its deficiencies.

10.  Make a diagram of the Kellogg receiver.

11.  Describe the direct-current receiver of the Automatic Electric Company.

12.  Describe and sketch the Dean receiver.

13.  Show the conventional symbols of a receiver.

14.  Describe exactly how, in a cell composed of a tin and a silver plate with dilute sulphuric acid as electrolyte, the current inside and outside of the cell will flow.

15.  Describe the phenomenon of polarization.

16.  What is local action of a cell?  How may it be prevented?

17.  Into how many classes may cells be divided?  Which class is most used in telephony?

18.  Describe the LeClanche cell.

19.  Sketch and describe an excellent form of dry cell.

20.  Show the conventional symbols for batteries.

21.  Sketch and describe the generator shunt switch and the generator cut-in switch.

22.  How may a pulsating current be derived from a magneto generator?

23.  Show conventional symbols for magneto generators.

24.  Sketch and describe the Western Electric polarized bell.

25.  Give conventional ringer symbols.

26.  What is the purpose of the hook switch?

27.  Make sketch and give description of Kellogg’s long lever hook switch.

28.  Describe and sketch the Western Electric short lever hook switch.

29.  Point out the principal difference between the desk stand hook switches of the Western Electric Company and of the Kellogg Switchboard and Supply Company.

30.  Give conventional symbols of hook switches.

REVIEW QUESTIONS

ON THE SUBJECT OF TELEPHONY

PAGES 143—­225

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1.  Describe an electromagnet and its function in telephony.