Ch 3

12. When propagation speed is multiplied by propagation time, we get the ________. A) wavelength of the signal B) throughput C) distance a signal or bit has traveled D) distortion factor

C) distance a signal or bit has traveled

19. Signals can be ________. A) digital B) analog C) either (a) or (b) D) neither (a) nor (b)

C) either (a) or (b)

20. A sine wave is ________. A) periodic and discrete B) aperiodic and discrete C) periodic and continuous D) aperiodic and continuous

C) periodic and continuous

7. A sine wave in the ______ domain can be represented by one single spike in the _____ domain. A) time; phase B) frequency; time C) time; frequency D) phase; time

C) time; frequency

2. _________ can impair a signal. A) Noise B) Attenuation C) Distortion D) All of the above

D) All of the above

14. The _________ product defines the number of bits that can fill the link. A) delay-amplitude B) frequency-amplitude C) bandwidth-period D) bandwidth-delay

D) bandwidth-delay

33. For a ______ channel, the Nyquist bit rate formula defines the theoretical maximum bit rate. A) low-pass B) bandpass C) noisy D) noiseless

D) noiseless

9. In a time-domain plot, the horizontal axis is a measure of ________. A) phase B) signal amplitude C) frequency D) time

D) time

15. _______ signals can have only a limited number of values. A) Digital B) Analog C) (a) or (b) D) None of the above

A) Digital

28. ________ is a type of transmission impairment in which an outside source such as crosstalk corrupts a signal. A) Noise B) Distortion C) Attenuation D) Decibel

A) Noise

4. A signal is measured at two different points. The power is P1 at the first point and P2 at the second point. The dB is 0. This means ________. A) P2 equals P1 B) P2 is zero C) P2 is much larger than P1 D) P2 is much smaller than P1

A) P2 equals P1

25. A(n)_________ signal is a composite analog signal with an infinite bandwidth. A) digital B) analog C) either (a) or (b) D) neither (a) nor (b)

A) digital

13. A _________ sine wave is not useful in data communications; we need to send a _______ signal. A) single-frequency; composite B) composite; single-frequency This is the correct answer. C) single-frequency; double-frequency D) none of the above

A) single-frequency; composite

29. _______ describes the position of the waveform relative to time 0. A) Amplitude B) Phase C) Frequency D) Voltage

B) Phase

10. _______ data are continuous and take continuous values. A) digital B) analog C) (a) or (b) D) none of the above

B) analog

27. The _____ of a composite signal is the difference between the highest and the lowest frequencies contained in that signal. A) period B) bandwidth C) frequency D) amplitude

B) bandwidth

31. As frequency increases, the period ________. A) increases B) decreases C) doubles D) remains the same

B) decreases

32. If the available channel is a ____ channel, we cannot send a digital signal directly to the channel. A) low-pass B) low rate C) bandpass D) high rate

C) bandpass

24. _____ signals can have an infinite number of values in a range. A) Analog B) Digital C) (a) or (b) D) None of the above

A) Analog

23. What is the bandwidth of a signal that ranges from 1 MHz to 4 MHz? A) 1 KHz B) 3 MHz C) 4 MHz D) none of the above

B) 3 MHz

6. ________ is a type of transmission impairment in which the signal loses strength due to the resistance of the transmission medium. A) Distortion B) Attenuation C) Noise D) Decibel

B) Attenuation

21. _______ data have discrete states and take discrete values. A) Analog B) Digital C) (a) or (b) D) None of the above

B) Digital

18. ________ is a type of transmission impairment in which the signal loses strength due to the different propagation speeds of each frequency that makes up the signal. A) Noise B) Distortion C) Attenuation D) Decibel

B) Distortion

3. ________is the rate of change with respect to time. A) Time B) Frequency C) Amplitude D) Voltage

B) Frequency

16. Before data can be transmitted, they must be transformed to ________. A) periodic signals B) electromagnetic signals C) aperiodic signals D) low-frequency sine waves

B) electromagnetic signals

34. In a frequency-domain plot, the horizontal axis measures the ________. A) phase B) frequency C) slope D) peak amplitude

B) frequency

11. Frequency and period are ______. A) proportional to each other B) inverse of each other C) the same D) none of the above

B) inverse of each other

5. Baseband transmission of a digital signal is possible only if we have a ____ channel. A) bandpass B) low-pass C) high rate D) low rate

B) low-pass

22. For a ______ channel, we need to use the Shannon capacity to find the maximum bit rate. A) noiseless B) noisy C) low-pass D) bandpass

B) noisy

30. Given two sine waves A and B, if the frequency of A is twice that of B, then the period of B is ________ that of A. A) one-half B) twice C) the same as D) indeterminate from

B) twice

17. Data can be ________. A) digital B) analog C) (a) or (b) D) none of the above

C) (a) or (b)

1. If the maximum amplitude of a sine wave is 2 V, the minimum amplitude is ________ V. A) 2 B) 1 C) -2 D) between -2 and 2

C) -2

26. A periodic signal completes one cycle in 0.001 s. What is the frequency? A) 1 Hz B) 100 Hz C) 1 KHz D) 1 MHz

C) 1 KHz

8. If the bandwidth of a signal is 5 KHz and the lowest frequency is 52 KHz, what is the highest frequency? A) 5 KHz B) 47 KHz C) 57 KHz D) 10 KHz

C) 57 KHz