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1 | |
AM and FM are examples of ________ modulation. |
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| | A) | Analog-to-analog |
| | B) | Analog-to-digital |
| | C) | Digital-to-digital |
| | D) | Digital-to-analog |
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2 | |
In QAM, both phase and ________ of a carrier frequency are varied. |
|
| | A) | Frequency |
| | B) | Bit rate |
| | C) | Amplitude |
| | D) | Baud rate |
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3 | |
Which of the following is most affected by noise? |
|
| | A) | PSK |
| | B) | FSK |
| | C) | QAM |
| | D) | ASK |
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4 | |
ASK, PSK, FSK, and QAM are examples of ________ modulation. |
|
| | A) | Analog-to-analog |
| | B) | Analog-to-digital |
| | C) | Digital-to-digital |
| | D) | Digital-to-analog |
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5 | |
If the baud rate is 400 for a 4-PSK signal, the bit rate is ________ bps. |
|
| | A) | 1600 100 |
| | B) | 800 |
| | C) | 400 |
| | D) | 100 |
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6 | |
If the bit rate for an ASK signal is 1200 bps, the baud rate is ________. |
|
| | A) | 300 |
| | B) | 400 |
| | C) | 600 |
| | D) | 1200 |
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7 | |
As the bit rate of an FSK signal increases, the bandwidth ________. |
|
| | A) | Remains the same |
| | B) | Decreases |
| | C) | Increases |
| | D) | Doubles |
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8 | |
In 16-QAM, there are 16 ________. |
|
| | A) | Phases |
| | B) | Combinations of phase and amplitude |
| | C) | Amplitudes |
| | D) | bps |
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9 | |
Which modulation technique involves tribits, eight different phase shifts, and one amplitude? |
|
| | A) | FSK |
| | B) | ASK |
| | C) | 4-PSK |
| | D) | 8-PSK |
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10 | |
If the bit rate for an FSK signal is 1200 bps, the baud rate is ________. |
|
| | A) | 300 |
| | B) | 400 |
| | C) | 600 |
| | D) | 1200 |
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11 | |
If the bit rate for a QAM signal is 3000 bps and a signal unit is represented by a tribit, what is the baud rate? |
|
| | A) | 300 |
| | B) | 400 |
| | C) | 1000 |
| | D) | 1200 |
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12 | |
If the baud rate for a QAM signal is 3000 and a signal unit is represented by a tribit, what is the bit rate? |
|
| | A) | 300 |
| | B) | 400 |
| | C) | 1000 |
| | D) | 9000 |
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13 | |
If the baud rate for a QAM signal is 1800 and the bit rate is 9000, how many bits are there per signal unit? |
|
| | A) | 3 |
| | B) | 4 |
| | C) | 5 |
| | D) | 6 |
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14 | |
Given an AM radio signal with a bandwidth of 10 KHz and the highest-frequency component at 705 KHz, what is the frequency of the carrier signal? |
|
| | A) | 705 KHz |
| | B) | 700 KHz |
| | C) | 710 KHz |
| | D) | Cannot be determined from given information |
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15 | |
A modulated signal is formed by ________. |
|
| | A) | Changing the carrier wave by the modulating signal |
| | B) | Quantization of the source data |
| | C) | Changing the modulating signal by the carrier wave |
| | D) | Sampling at the Nyquist frequency |
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16 | |
If FCC regulations are followed, the carrier frequencies of adjacent AM radio stations are ________ apart. |
|
| | A) | 5 KHz |
| | B) | 10 KHz |
| | C) | 200 KHz |
| | D) | 530 KHz |
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17 | |
If FCC regulations are followed, ________ potential FM stations are theoretically possible in a given area. |
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| | A) | 50 |
| | B) | 100 |
| | C) | 133 |
| | D) | 150 |
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18 | |
When an ASK signal is decomposed, the result is ________. |
|
| | A) | An infinite number of sine waves |
| | B) | Always one sine wave |
| | C) | Always two sine waves |
| | D) | None of the above |
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19 | |
The bandwidth of an FM signal requires 10 times the bandwidth of the _______ signal. |
|
| | A) | Bipolar |
| | B) | Sampling |
| | C) | Carrier |
| | D) | Modulating |
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20 | |
Modulation of an analog signal can be accomplished through changing the ________ of the carrier signal. |
|
| | A) | Amplitude |
| | B) | Frequency |
| | C) | Phase |
| | D) | Any of the above |
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21 | |
For a telephone line, the bandwidth for voice is usually _______ the bandwidth for data. |
|
| | A) | Less than |
| | B) | Greater than |
| | C) | Twice |
| | D) | Equivalent to |
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22 | |
For a given bit rate, the minimum bandwidth for ASK is ________ the minimum bandwidth for FSK. |
|
| | A) | Less than |
| | B) | Equivalent to |
| | C) | Greater than |
| | D) | Twice |
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23 | |
What is the object of trellis coding? |
|
| | A) | To narrow the bandwidth |
| | B) | To increase the data rate |
| | C) | To reduce the error rate |
| | D) | To simplify modulation |
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24 | |
A modulator converts a(n)________ signal to a(n) ________ signal. |
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| | A) | Digital; analog |
| | B) | Analog; digital |
| | C) | PSK; FSK |
| | D) | FSK; PSK |
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25 | |
A 56K modem can download at a rate of _______ Kbps and upload at a rate of ________ Kbps. |
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| | A) | 56.6; 33.6 |
| | B) | 56.6; 56.6 |
| | C) | 33.6; 33.6 |
| | D) | 33.6; 56.6 |
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26 | |
For FSK, as the difference between the two carrier frequencies increases, the bandwidth ________. |
|
| | A) | Remains the same |
| | B) | Decreases |
| | C) | Increases |
| | D) | Halves |
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27 | |
The bit rate always equals the baud rate in which type of signal? |
|
| | A) | FSK |
| | B) | QAM |
| | C) | 4-PSK |
| | D) | All the above |
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28 | |
Which ITU-T modem standard uses trellis coding? |
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| | A) | V.32 |
| | B) | V.33 |
| | C) | V.34 |
| | D) | (a) and (b) |
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29 | |
In trellis coding the number of data bits is ________ the number of transmitted bits. |
|
| | A) | Less than |
| | B) | More than |
| | C) | Equal to |
| | D) | Double that of |