Review Questions

1. Distinguish between a uniform line and a non-uniform line.

2. In communication, what frequencies are transmitted by open-wire lines?

3. What types of distortion may occur in open-wire lines and terminal equipment?

4. How do electrically long lines differ from electrically short lines? Give an example of each. How is each considered in design calculations?

5. Discuss the linear electrical constants of a transmission line, explaining the fundamental nature and variations of each constant.

6. Of what significance are the phase constant β and the attenuation constant α?

7. Define, and explain, the practical significance of characteristic impedance. What comparable term was considered in the preceding chapter?

8. Why is the input impedance of a line with any termination different from the characteristic impedance of that line?

9. What is the nature of the characteristic impedance of any open-circuited or short-circuited line?

10. Briefly discuss the importance of the reflected wave in determining transmission-line phenomena.

11. What is meant by the term stationary, or standing, wave? Explain why this term is misleading.

12. What are antinodes, and what are nodes? How are they caused? How are they measured?

13. What causes skin effect? Proximity effect?

14. Is skin effect of practical importance? Where? To what extent?

15. Discuss the nature of the losses occurring in telephone insulators, insulator pins, and crossarms.

16. Could a measurement using equation 71 be used to determine the conductance (G) values of Table IV? If not, how would they be determined?

17. Compare the constants of an open-wire line at audio frequencies with those of the same line at radio frequencies.

18. Compare α, β, and Z₀ for a line at audio frequencies, and for the same line at radio frequencies.

19. What is an exponential transmission line, and what interesting property does it have? It is similar to what network of the preceding chapter?

20. What is meant by radiation loss as given by equation 81?

21. What is a phantom circuit? A repeating coil?

22. Explain how, at radio frequencies, a transmission line can be used as a transformer.

23. How would you determine the characteristic impedance of an audio-frequency line? Of a radio-frequency line?

24. How would you determine line constants at both audio and radio frequencies?

25. What is the approximate velocity of propagation of a typical audio-frequency line? What is the attenuation? Repeat for a typical radio-frequency line.