This set of Data communication and Networking Multiple Choice Questions and Answers (MCQs) focuses on “Digital to Analog to Encoding / Modulation Techniques – Amplitude-shift keying (ASK)- Frequency-shift keying (FSK)- Phase-shift keying (PSK)- Quadrature Amplitude Modulation(QAM)”.
1. The process of changing one of the characteristics of a carrier analog signal based on the information in a digital signal is called _______ conversion
- analog-to-analog
- analog-to-digital
- digital-to-analog
- digital-to-digital
C. digital-to-analog
2. In _______ the frequency of the carrier signal is varied based on the information in a digital signal
- ASK
- PSK
- FSK
- QAM
C. FSK
3. In _______ the amplitude of the carrier signal is varied based on the information in a digital signal.
- ASK
- PSK
- FSK
- QAM
A. ASK
4. In _______ the phase of the carrier signal is varied based on the information in a digital signal
- ASK
- PSK
- FSK
- QAM
B. PSK
5. In _______ the phase and amplitude of the carrier signal is varied based on the information in a digital signal.
- ASK
- PSK
- FSK
- QAM
D. QAM
6. Most modern modems use _______ for digital to analog modulation
- ASK
- PSK
- FSK
- QAM
D. QAM
7. _______ rate is the number of bits per second; _______ rate is the number of signal units per second
- Baud; bit
- Bit; baud
- Baud; base
- Base; baud
B. Bit; baud
8. _______ rate is always less than or equal to _______ rate
- Baud; bit
- Bit; baud
- Baud; base
- Base; baud
A. Baud; bit
9. If the bit rate is 1200 bps and there are 4 bits for each signal element, then the baud rate is _______.
- 4800
- 1200
- 400
- 300
D. 300
10. If the baud rate is 1200 and there are 4 bits for each signal element, then the bit rate is _______
- 4800
- 1200
- 400
- 300
A. 4800
11. An ASK modulated signal has a bit rate of 2000 bps; the baud rate is _______
- 2000
- 1000
- 4000
- none of the above
A. 2000
12. A 2-PSK modulated signal has a bit rate of 2000 bps; the baud rate is _______
- 2000
- 1000
- 4000
- none of the above
A. 2000
13. A 4-PSK modulated signal has a bit rate of 2000 bps; the baud rate is _______.
- 2000
- 1000
- 4000
- none of the above
B. 1000
14. An 8-PSK modulated signal has a baud rate of 2000; the bit rate is _______ bps
- 8000
- 6000
- 2000
- 1000
B. 6000
15. An 8-QAM modulated signal has a baud rate of 2000; the bit rate is _______ bps
- 8000
- 6000
- 2000
- 1000
B. 6000
16. A 32-QAM modulated signal has a baud rate of 2000; the bit rate is _______ bps
- 16000
- 10000
- 4000
- 1000
B. 10000
17. A 128-QAM modulated signal has a baud rate of 2000; there are _______ bits per baud.
- 2000
- 1000
- 7
- 6
C. 7
18. A 256-QAM modulated signal has a bit rate of 8000; there are _______ bits per baud
- 8000
- 4000
- 8
- 7
C. 8
19. OOK is a type of _______ modulation.
- ASK
- PSK
- FSK
- QAM
A. ASK
20. The modulation technique most affected by noise is _______
- ASK
- PSK
- FSK
- QAM
A. ASK
21. For _______, the minimum bandwidth required for transmission is equal to the baud rate
- ASK
- PSK
- FSK
- a and b
D. a and b
22. The minimum bandwidth for an ASK modulated signal with a baud rate of 5000 is _______ Hz.
- 1000
- 2500
- 5000
- 10000
C. 5000
23. On a 16-QAM-constellation diagram, each constellation point represents a _______
- dibit
- tribit
- quadbit
- pentabit
C. quadbit
24. In which type of modulation can the bit rate be four times the baud rate?
- ASK
- FSK
- PSK
- None of the above
C. PSK
25. In which type of modulation can the bit rate be three times the baud rate?
- ASK
- FSK
- PSK
- None of the above
D. None of the above
26. In which type of modulation can the bit rate be half the baud rate?
- ASK
- FSK
- PSK
- None of the above
D. None of the above
27. In _______ modulation, the bit rate is 8 times the baud rate
- 8-QAM
- 64-QAM
- 256-QAM
- None of the above
C. 256-QAM
28. In _______ modulation, the baud rate is 1/4 times the bit rate.
- 4-QAM
- 2-PSK
- 4-PSK
- None of the above
D. None of the above
29. In a dibit modulation, the number of points in the constellation is _______
- 2
- 4
- 8
- None of the above
B. 4
30. In a tribit modulation, the number of points in the constellation is _______
- 2
- 4
- 8
- None of the above
C. 8
31. A 4-PSK constellation is a _________ modulation
- dibit
- tribit
- quadbit
- None of the above
A. dibit
32. An 8-QAM constellation is a _________ modulation
- dibit
- tribit
- quadbit
- None of the above
B. tribit
33. The number of points in the constellation of an 8-PSK modulation is _______ the number of points for an 8-QAM
- greater than
- less than
- equal to
- None of the above
C. equal to
34. If the baud rate for modulation scheme A is two times the baud rate for modulation scheme B, the required bandwidth for scheme A is ___________ the one for scheme B
- more than
- less than
- equal to
- we cannot tell
A. more than
35. If the bit rate for modulation scheme A is two times the bit rate for modulation scheme B, the required bandwidth for scheme A is ___________ the one for scheme B.
- more than
- less than
- equal to
- we cannot tell
D. we cannot tell