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1 | |
Before data can be transmitted, they must be transformed to ________. |
|
| | A) | periodic signals |
| | B) | electromagnetic signals |
| | C) | aperiodic signals |
| | D) | low-frequency sine waves |
|
2 | |
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 |
|
3 | |
In a frequency-domain plot, the horizontal axis measures the ________. |
|
| | A) | peak amplitude |
| | B) | frequency |
| | C) | phase |
| | D) | slope |
|
4 | |
In a time-domain plot, the horizontal axis is a measure of ________. |
|
| | A) | signal amplitude |
| | B) | frequency |
| | C) | phase |
| | D) | time |
|
5 | |
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 |
|
6 | |
What is the bandwidth of a signal that ranges from 1 MHz to 4 MHz? |
|
| | A) | 4 MHz |
| | B) | 1 KHz |
| | C) | 3 MHz |
| | D) | none of the above |
|
7 | |
As frequency increases, the period ________. |
|
| | A) | decreases |
| | B) | increases |
| | C) | remains the same |
| | D) | doubles |
|
8 | |
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 |
|
9 | |
A sine wave is ________. |
|
| | A) | periodic and continuous |
| | B) | aperiodic and continuous |
| | C) | periodic and discrete |
| | D) | aperiodic and discrete |
|
10 | |
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 |
|
11 | |
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 is zero |
| | B) | P2 equals P1 |
| | C) | P2 is much larger than P1 |
| | D) | P2 is much smaller than P1 |
|
12 | |
________ is a type of transmission impairment in which the signal loses strength due to the resistance of the transmission medium. |
|
| | A) | Attenuation |
| | B) | Distortion |
| | C) | Noise |
| | D) | Decibel |
|
13 | |
________ 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) | Attenuation |
| | B) | Distortion |
| | C) | Noise |
| | D) | Decibel |
|
14 | |
________ is a type of transmission impairment in which an outside source such as crosstalk corrupts a signal. |
|
| | A) | Attenuation |
| | B) | Distortion |
| | C) | Noise |
| | D) | Decibel |
|
15 | |
When propagation speed is multiplied by propagation time, we get the ________. |
|
| | A) | throughput |
| | B) | wavelength of the signal |
| | C) | distortion factor |
| | D) | distance a signal or bit has traveled |
|
16 | |
Data can be ________. |
|
| | A) | analog |
| | B) | digital |
| | C) | (a) or (b) |
| | D) | none of the above |
|
17 | |
_______ data are continuous and take continuous values. |
|
| | A) | analog |
| | B) | digital |
| | C) | (a) or (b) |
| | D) | none of the above |
|
18 | |
_______ data have discrete states and take discrete values. |
|
| | A) | Analog |
| | B) | Digital |
| | C) | (a) or (b) |
| | D) | None of the above |
|
19 | |
Signals can be ________. |
|
| | A) | analog |
| | B) | digital |
| | C) | either (a) or (b) |
| | D) | neither (a) nor (b) |
|
20 | |
_____ signals can have an infinite number of values in a range. |
|
| | A) | Analog |
| | B) | Digital |
| | C) | (a) or (b) |
| | D) | None of the above |
|
21 | |
_______ signals can have only a limited number of values. |
|
| | A) | Analog |
| | B) | Digital |
| | C) | (a) or (b) |
| | D) | None of the above |
|
22 | |
Frequency and period are ______. |
|
| | A) | inverse of each other |
| | B) | proportional to each other |
| | C) | the same |
| | D) | none of the above |
|
23 | |
________is the rate of change with respect to time. |
|
| | A) | Amplitude |
| | B) | Time |
| | C) | Frequency |
| | D) | Voltage |
|
24 | |
_______ describes the position of the waveform relative to time 0. |
|
| | A) | Frequency |
| | B) | Phase |
| | C) | Amplitude |
| | D) | Voltage |
|
25 | |
A sine wave in the ______ domain can be represented by one single spike in the _____ domain. |
|
| | A) | time; frequency |
| | B) | frequency; time |
| | C) | time; phase |
| | D) | phase; time |
|
26 | |
A _________ sine wave is not useful in data communications; we need to send a _______ signal. |
|
| | A) | composite; single-frequency |
| | B) | single-frequency; composite |
| | C) | single-frequency; double-frequency |
| | D) | none of the above |
|
27 | |
The _____ of a composite signal is the difference between the highest and the lowest frequencies contained in that signal. |
|
| | A) | frequency |
| | B) | period |
| | C) | bandwidth |
| | D) | amplitude |
|
28 | |
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) |
|
29 | |
Baseband transmission of a digital signal is possible only if we have a ____ channel. |
|
| | A) | low-pass |
| | B) | bandpass |
| | C) | low rate |
| | D) | high rate |
|
30 | |
If the available channel is a ____ channel, we cannot send a digital signal directly to the channel. |
|
| | A) | low-pass |
| | B) | bandpass |
| | C) | low rate |
| | D) | high rate |
|
31 | |
For a ______ channel, the Nyquist bit rate formula defines the theoretical maximum bit rate. |
|
| | A) | noisy |
| | B) | noiseless |
| | C) | bandpass |
| | D) | low-pass |
|
32 | |
For a ______ channel, we need to use the Shannon capacity to find the maximum bit rate. |
|
| | A) | noisy |
| | B) | noiseless |
| | C) | bandpass |
| | D) | low-pass |
|
33 | |
_________ can impair a signal. |
|
| | A) | Attenuation |
| | B) | Distortion |
| | C) | Noise |
| | D) | All of the above |
|
34 | |
The _________ product defines the number of bits that can fill the link. |
|
| | A) | bandwidth-period |
| | B) | frequency-amplitude |
| | C) | bandwidth-delay |
| | D) | delay-amplitude |