Communication Systems – Important Questions for AISSCE 2010

VERY SHORT ANSWER AND SHORT ANSWER QUESTIONS

1. What do you mean by communication?
2. What is a digital signal?
3. What is an analog signal?
4. Mention the different types of communication systems?
5. What do you mean by radio communication?
6. What is modulation?
7. Distinguish modulating wave, carrier wave and modulated wave.
8. What are the different methods of modullation?
9. What is amplitude modulation?
10. What is frequency modulation?
11. What is phase modulation?
12. Define modulation factor?
13. Write an expression to describe the frequency spectrum of the modulated signal.
14. What do you mean by bandwidth in amplitude modulation?
15. Define frequency deviation.
16. What are the limitations of amplitude modulation?
17. Write an expression for modulation index.
18. Write the advantages of frequency modulation.
19. Give two disadvantages of frequency modulation.
20. What is the importance of modulation index?
21. What is demodulation?
22. WHat is pulse amplitude modulation?
23. Draw a schematic diagram to illustrate the basic elements of a communication system to transmit and receive audio signals.
24. What is sampling?
25. What is a modem?
26. What is an artificial satellite?
27. What is a geostationary satellite?
28. What is remote sensing?
29. Write the merits of satellite communication?
30. Draw the basic circuit diagram for demodulatiom of am waves.
31. What is UHF band?
32. Write an expression for the range of transmission by a Tv antenna of height h.
33. Which part of the electromagnetic spectrum is utilised for operating a radar?
34. Why ground waves are limited to a frequency of 1500Hz?
35. Name two primary requirements for optical transmission.
36. What is an optical detector? Write its characteristics.
37. What is FAX? Explain its working.
38. What is email? How does it work?
39. Explain PAM, PDM (PWM) and PPM
40. Explain gow an analogue signal is converted to digital signal?

LONG ANSWER QUESTIONS

1. Why is modulation necessary in long distance communication?
2. Draw a circuit diagram for demodulation and explain its working.
3. (a) Explain the use of geostationary satellites in communication. (b) Explain the working of remote sensing
4. Explain the working of a modem.