MCQOPTIONS
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MCQOPTIONS
This section includes 203 Mcqs, each offering curated multiple-choice questions to sharpen your Computer Networks knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The Nyquist formula gives us any signal level while Shannon capacity gives us the |
| A. | Lower Limit |
| B. | Upper Limit |
| C. | Specific signal level |
| D. | Both b and c |
| Answer» C. Specific signal level | |
| 52. |
According to Fourier analysis, any composite signal is a combination of sine waves with |
| A. | diff frequencies amplitude, and phase |
| B. | different frequencies |
| C. | same frequencies |
| D. | same frequencies with amplitude and phase |
| Answer» B. different frequencies | |
| 53. |
In _____ transmission, the frequency of the carrier signal is modulated to follow the changing voltage level (amplitude) of the modulating signal. The peak amplitude and phase of the carrier signal remain constant, but as the amplitude of the information signal changes, the frequency of the carrier changes correspondingly. |
| A. | AM |
| B. | PM |
| C. | FM |
| D. | none of the above |
| Answer» D. none of the above | |
| 54. |
________ is normally referred to as mB/nB coding; it replaces each m-bit group with an n-bit group. |
| A. | Block coding |
| B. | Line coding |
| C. | Scrambling |
| D. | None of the above |
| Answer» B. Line coding | |
| 55. |
________ is the process of converting digital data to a digital signal. |
| A. | Block coding |
| B. | Line coding |
| C. | Scrambling |
| D. | None of the above |
| Answer» C. Scrambling | |
| 56. |
Two common scrambling techniques are ________. |
| A. | NRZ and RZ |
| B. | AMI and NRZ |
| C. | B8ZS and HDB3 |
| D. | Manchester and differential Manchester |
| Answer» D. Manchester and differential Manchester | |
| 57. |
Which encoding method uses alternating positive and negative values for 1s? |
| A. | NRZ-I |
| B. | RZ |
| C. | Manchester |
| D. | AMI |
| Answer» E. | |
| 58. |
Which of the following encoding methods does not provide for synchronization? |
| A. | NRZ-L |
| B. | RZ |
| C. | NRZ-I |
| D. | Manchester |
| Answer» B. RZ | |
| 59. |
Block coding can help in _______ at the receiver. |
| A. | Synchronization |
| B. | Error detection |
| C. | Attenuation |
| D. | both (a) and (b) |
| Answer» E. | |
| 60. |
The Nyquist theorem specifies the minimum sampling rate to be_______. |
| A. | equal to the lowest frequency of a signal |
| B. | equal to the highest frequency of a signal |
| C. | twice the bandwidth of a signal |
| D. | twice the highest frequency of a signal |
| Answer» E. | |
| 61. |
PCM is an example of _______ conversion. |
| A. | digital-to-digital |
| B. | digital-to-analog |
| C. | analog-to-analog |
| D. | analog-to-digital |
| Answer» E. | |
| 62. |
If the frequency spectrum of a signal has a bandwidth of 500 Hz with the highest frequency at 600 Hz, what should be the sampling rate, according to the Nyquist theorem? |
| A. | 200 samples/s |
| B. | 500 samples/s |
| C. | 1000 samples/s |
| D. | 1200 samples/s |
| Answer» E. | |
| 63. |
In _______ transmission, a start bit and a stop bit frame a character byte. |
| A. | asynchronous serial |
| B. | synchronous serial |
| C. | parallel |
| D. | (a) and (b) |
| Answer» B. synchronous serial | |
| 64. |
The level of the signal is inversely proportional to the |
| A. | Reliability of a system |
| B. | Efficiency of a system |
| C. | Accuracy of a system |
| D. | Bandwidth of a system |
| Answer» B. Efficiency of a system | |
| 65. |
A repeater takes a weakened or corrupted signal and ............... it. |
| A. | Amplifies |
| B. | Regenerates |
| C. | Resample |
| D. | Reroute |
| Answer» C. Resample | |
| 66. |
In ___________ there is always a transition at the middle of the bit, but the bit values are determined at the beginning of the bit. If the next bit is 0, there is a transition; if the next bit is 1, there is none. |
| A. | Manchester |
| B. | differential Manchester |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» C. both (a) and (b) | |
| 67. |
In ______, the change or lack of change in the level of the voltage determines the value of the bit. |
| A. | NRZ-I |
| B. | NRZ-L |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» B. NRZ-L | |
| 68. |
In _____, the level of the voltage determines the value of the bit. |
| A. | NRZ-I |
| B. | NRZ-L |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» C. both (a) and (b) | |
| 69. |
In _______encoding, we use three levels: positive, zero, and negative. |
| A. | unipolar |
| B. | bipolar |
| C. | polar |
| D. | none of the above |
| Answer» C. polar | |
| 70. |
In ______ schemes, the voltages are on the both sides of the time axis. For example, the voltage level for 0 can be positive and the voltage level for 1 can be negative. |
| A. | polar |
| B. | bipolar |
| C. | unipolar |
| D. | all of the above |
| Answer» B. bipolar | |
| 71. |
The idea of RZ and the idea of NRZ-I are combined into the ________ scheme. |
| A. | Manchester |
| B. | differential Manchester |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» C. both (a) and (b) | |
| 72. |
Calculate the theoretical channel capacity. If SNR(dB) = 36 and the channel bandwidth is 2 MHz. |
| A. | 12 Mbps |
| B. | 24 Mbps |
| C. | 16 Mbps |
| D. | 32 Mbps |
| Answer» C. 16 Mbps | |
| 73. |
Calculate the theoretical highest bit rate of a regular telephone line. The signal-to-noise ratio is usually 3162. |
| A. | 34.860 kbps |
| B. | 17.40 kbps |
| C. | 11.62 kbps |
| D. | none of the Mentioned |
| Answer» B. 17.40 kbps | |
| 74. |
In decoding a digital signal, the receiver calculates a running average of the received signal power, called the _______. |
| A. | baseline |
| B. | base |
| C. | line |
| D. | none of the above |
| Answer» B. base | |
| 75. |
A _________ digital signal includes timing information in the data being transmitted. |
| A. | self-synchronizing |
| B. | self-modulated |
| C. | self-transmitted |
| D. | none of the above |
| Answer» B. self-modulated | |
| 76. |
In _________ transmission, we send bits one after another without start or stop bits or gaps. It is the responsibility of the receiver to group the bits. |
| A. | synchronous |
| B. | asynchronous |
| C. | isochronous |
| D. | none of the above |
| Answer» B. asynchronous | |
| 77. |
The signal rate is sometimes called the ____ rate. |
| A. | baud |
| B. | bit |
| C. | signal |
| D. | none of the above |
| Answer» B. bit | |
| 78. |
The ________ rate defines the number of data elements sent in 1s; the ______ rate is the number of signal elements sent in 1s. |
| A. | data; signal |
| B. | signal; data |
| C. | baud; bit |
| D. | none of the above |
| Answer» B. signal; data | |
| 79. |
The minimum bandwidth of Manchester and differential Manchester is ____ that of NRZ. |
| A. | the same as |
| B. | twice |
| C. | thrice |
| D. | none of the above |
| Answer» C. thrice | |
| 80. |
In Manchester and differential Manchester encoding, the transition at the middle of the bit is used for __________. |
| A. | bit transfer |
| B. | baud transfer |
| C. | synchronization |
| D. | none of the above |
| Answer» D. none of the above | |
| 81. |
If the bit rate for a 16-QAM signal is 4000 bps, what is the baud rate? |
| A. | 300 |
| B. | 400 |
| C. | 1000 |
| D. | 1200 |
| Answer» D. 1200 | |
| 82. |
Which quantization level results in a more faithful reproduction of the signal? |
| A. | 2 |
| B. | 8 |
| C. | 16 |
| D. | 32 |
| Answer» E. | |
| 83. |
In ______ transmission, we send 1 start bit (0) at the beginning and 1 or more stop bits (1s) at the end of each byte. |
| A. | synchronous |
| B. | asynchronous |
| C. | isochronous |
| D. | none of the above |
| Answer» C. isochronous | |
| 84. |
_______ encoding has a transition at the beginning of each 0 bit. |
| A. | RZ |
| B. | Manchester |
| C. | Differential Manchester |
| D. | All the above |
| Answer» D. All the above | |
| 85. |
_______ provides redundancy to ensure synchronization and inherent error detection. |
| A. | Block coding |
| B. | Line coding |
| C. | Scrambling |
| D. | None of the above |
| Answer» B. Line coding | |
| 86. |
How many carrier frequencies are used in BASK? |
| A. | 2 |
| B. | 1 |
| C. | 0 |
| D. | none of the above |
| Answer» B. 1 | |
| 87. |
The term that refers to infinite no of values in the range is |
| A. | Peak |
| B. | Analog Signal |
| C. | Digital Signal |
| D. | None of the above |
| Answer» C. Digital Signal | |
| 88. |
Frequency is expressed in |
| A. | Second |
| B. | Nanosecond |
| C. | Hertz |
| D. | Megahertz |
| Answer» D. Megahertz | |
| 89. |
Analog-to-analog conversion is needed if the available bandwidth is _______. |
| A. | low-pass |
| B. | band-pass |
| C. | either (a) or (b) |
| D. | neither (a) nor (b |
| Answer» C. either (a) or (b) | |
| 90. |
The term that refers to loss of strength of a signal is called |
| A. | attenuation |
| B. | distortion |
| C. | Noise |
| D. | Impairments |
| Answer» B. distortion | |
| 91. |
In _______ encoding, the duration of the bit is divided into two halves. The voltage remains at one level during the first half and moves to the other level in the second half. The transition at the middle of the bit provides synchronization. |
| A. | Manchester |
| B. | differential Manchester |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 92. |
Signal to Noise Ratio is the ratio of the two |
| A. | Signals |
| B. | Powers |
| C. | Noise |
| D. | Frequencies |
| Answer» C. Noise | |
| 93. |
Which of the following is not the possible ways of data exchange? |
| A. | Simplex |
| B. | Multiplex |
| C. | Half-duplex |
| D. | Full-duplex |
| Answer» C. Half-duplex | |
| 94. |
In _____ transmission, the phase of the carrier signal is modulated to follow the changing voltage level (amplitude) of the modulating signal. |
| A. | AM |
| B. | PM |
| C. | FM |
| D. | none of the above |
| Answer» C. FM | |
| 95. |
A period of 100 ms in microseconds would be equals to |
| A. | 103us |
| B. | 105us |
| C. | 107us |
| D. | 109us |
| Answer» C. 107us | |
| 96. |
Which of the following is not a digital-to-analog conversion? |
| A. | ASK |
| B. | PSK |
| C. | FSK |
| D. | AM |
| Answer» E. | |
| 97. |
A channel has a 1-MHz bandwidth. The SNR for this channel is 63. What is the appropriate bit rate? |
| A. | 4 Mbps |
| B. | 6 Mbps |
| C. | 8 Mbps |
| D. | 12 Mbps |
| Answer» C. 8 Mbps | |
| 98. |
Frequency and period are ______. |
| A. | inverse of each other |
| B. | proportional to each other |
| C. | the same |
| D. | none of the above |
| Answer» B. proportional to each other | |
| 99. |
_______ signals can have only a limited number of values. |
| A. | Analog |
| B. | Digital |
| C. | (a) or (b) |
| D. | None of the above |
| Answer» C. (a) or (b) | |
| 100. |
_______ data have discrete states and take discrete values. |
| A. | Analog |
| B. | Digital |
| C. | (a) or (b) |
| D. | None of the above |
| Answer» C. (a) or (b) | |