1. Describe the three characteristics of a sine wave.
2. What is the spectrum of a signal?
3. Contrast an analog signal with a digital signal?
4. A signal has been received that only has value of -1, 0, and 1. Is this an analog or a digital signal?
5. What is the relationship between period and frequency?
6. What are the units of period?
7. What are the units of frequency?
8. What does the amplitude of a signal measure?
9. What does the frequency of a signal measure?
10. What does the phase of a signal measure?
11. Which type of plot shows the amplitude of a signal at a given time?
12. How can a composite signal be decomposed into its individual frequencies?
13. What is a bit interval, and what is its counterpart in an analog signal?
14. What is bit rate, and what is its counterpart in an analog signal?
15. Name three types of transmission impairment.
16. What does a decibel measure?
17. What is the relationship between propagation speed and propagation time?
18. What is the wavelength of a signal and how is it calculated?
19. What does the Shannon capacity have to do with communications?
Multiple Choice Questions
20. Before data can be transmitted, they must be transformed to _____________. a) Periodic signals
b) Electromagnetic signal
c) Aperiodic signal
d) Low-frequency sine waves
21. 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
22. Which of the following can be determined from a frequency-domain graph of a signal? a) Frequency
d) All the above
23. Which of the following can be determined from a frequency-domain graph of a signal? a) Bandwidth
d) All the above
24. In a frequency-domain plot, the vertical axis measure the ___________. a) Peak amplitude
25. In a frequency-domain plot, the horizontal axis measures the __________. a) Peak amplitude
26. In a time-domain plot, the vertical axis is a measure of ___________. a) Amplitude
27. In a time-domain plot, the horizontal axis is a measure of __________. a) Signal amplitude
28. 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) 10 KHz
c) 47 KHz
d) 57 KHz
29. What is the bandwidth of a signal that ranges from 40 KHz to 4 MHz? a) 36 MHz
b) 360 KHz
c) 3.96 MHz
d) 396 KHz
30. When one of the components of a signal has a frequency of zero, the average amplitude of the signal _________. a) Is greater than zero
b) Is less than zero
c) Is zero
d) (a) or (b)
31. A periodic signal can always be decomposed into __________. a) Exactly an odd number of sine waves
b) A set of sine waves
c) A set of sine waves, one of which must have a phase of 00 d) None of the above
32. As frequency increases, the period ____________.
c) Remains the same
33. 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
c) The same as
d) Indeterminate from
34. A sine wave is ___________.
a) Periodic and continuous
b) Aperiodic and continuous