This is the Multiples Choice Questions Part 2 of the Series in Digital and Data Communication Networks as one of the Communications Engineering topic. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize in each and every questions compiled here taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies, Communications Books, Journals and other Communications References.
Online Questions and Answers Topic Outline
- MCQs in Bit and and Binary Transmission
- MCQs in Signaling Rate
- MCQs in Error Probability, Digital Filtering, Switching, Packet Circuit, Vertical Circuit
- MCQs in Open systems Interconnection
- MCQs in Multiplying, Modulation and Synchronization
- MCQs in Pulse Code Modulation, Companding, Encoding, Bandwidth and Signal to Noise Ratio
- MCQs in Delta Modulation, Slope Overload, Adaptive Delta Modulation, Codes and Protocol
- MCQs in Error Detection and Correction, Digital Carrier systems
- MCQs in Frequency Shift Keying, Phase Shift Keying, Differential Phase Shift keying
- MCQs in DC nature of data transmission, loops, Neutral and Polar
- MCQs in Binary transmission and the concept of time
- MCQs in Asynchronous and Synchronous, timing, Distortion, Bits, band, WPM
- MCQs in Data Interface standards, Data input/output devices
- MCQs in Digital Transmission on analog channel, Modulation-demodulation schemes parameters
- MCQs in Circuit conditioning, Modem Applications
- MCQs in Serial and Parallel Transmission
MCQs in Digital and Data Communication Networks Series
Following is the list of multiple choice questions in this brand new series:
Continue Practice Exam Test Questions Part II of the Series
51. Two-state (binary) communications systems are better because
- a. They can interface directly with the analog telephone network
- b. The components are simpler, less costly, and more reliable
- c. People think better in binary
- d. Interstate calls are less costly
52. Codes are always
- a. Eight bits per character
- b. Either seven or eight bits per character
- c. Agreed upon in advance between sender receiver
- d. The same in all modern computers
53. DCE and DTE
- a. Means “digital communications equipment” and “digital termination equipment”
- b. Are connected by either two or four wires
- c. Refer to the modem and the computer or terminal, respectively
- d. Any one of the above
54. The correctness and the accuracy of the transmitted message content is
- a. Verified by the modem
- b. Determined by the sender and receiver, not by the communications system
- c. Ensured by use of digital techniques
- d. None of the above
55. Serial printers
- a. Are used to transmit grain prices
- b. Are faster than CRT terminals, and offer more flexibility
- c. Print one character at a time
- d. Usually use serial interfaces
56. Ergonomics
- a. Involves the interface between people and machines, such as terminals
- b. Is the application of ergo-economics to communications
- c. Utilizes three-level ergo-coding for transmission over certain channels
- d. All of the above
57. Serial and parallel transmission
- a. Differ in how many bits are transferred per character
- b. Are used in synchronous and asynchronous systems, respectively
- c. Both a and b
- d. Differ in whether the bits are on separate wires or on one
58. Asynchronous transmission
- a. Is less efficient than synchronous, but simpler
- b. Is much faster than synchronous transmission
- c. Is another name for isochronous transmission
59. The amount of uncertainty in a system of symbols is also called
- a. Bandwidth
- b. Loss
- c. Entropy
- d. Quantum
60. Redundancy measures
- a. Transmission rate of a system
- b. How likely symbols are to be repeated
- c. Time between failures
- d. System cost
61. Loading refers to the addition of
- a. Resistors
- b. Capacitors
- c. Bullets
- d. Inductance
62. Transmission of binary signals requires
- a. Less bandwidth than analog
- b. More bandwidth than analog
- c. The same bandwidth as analog
- d. Cannot be compared with the transmission of analog signals
63. RS-232, RS-449, RS-530, V.24, and X.21 are examples of
- a. Standard for various types of transmission channels
- b. Standard for interfaces between terminal and modems
- c. Standards for between modems and transmission facilities
- d. Standards for end-to-end performance of data communications system
64. What is one principal difference between synchronous and asynchronous transmission?
- a. The bandwidth required is different
- b. The pulse heights are different
- c. The clocking is mixed with the data in asynchronous
- d. The clocking is derived from the data in synchronous transmission
65. Synchronous modems cost more than asynchronous modems because
- a. They are larger
- b. They must contain clock recovery circuits
- c. The production volume is larger
- d. They must operate on a larger bandwidth
66. The scrambler in a synchronous modem is in the
- a. Control section
- b. Receiver section
- c. Transmitter section
- d. Terminal section
67. Binary codes are sometimes transformed in modems into
- a. Hexadecimal
- b. Huffman codes
- c. Gray code
- d. Complementary codes
68. The digital-to-analog converter in a synchronous modem sends signals to the
- a. Modulator
- b. Transmission line
- c. Terminal
- d. Equalizer
69. The transmission signal coding method for T1 carrier is called
- a. Binary
- b. NRZ
- c. Bipolar
- d. Manchester
70. The receiver equalizer in a synchronous modem is called
- a. A compromise equalizer
- b. A statistical equalizer
- c. An adaptive equalizer
- d. An impairment equalizer
71. Communications protocols always have a
- a. Set of symbols
- b. Start of header
- c. Special flag symbol
- d. BCC
72. The Baudot code uses how many bits per symbol?
- a. 9
- b. 7
- c. 5
- d. 8
73. How many messages may be acknowledged on a BiSync link?
- a. 1
- b. 2
- c. 4
- d. 8
74. Which code set is used to BiSync when using VRC/LRC but not operating in transparency mode
- a. EBCDIC
- b. ASCII
- c. SBT
- d. Fieldata
75. One primary difference between Digital Data Communications Message Protocol (DDCMP) and Synchronous Data Link Control (SDLC) is
- a. DDCMP does not have a transparent mode
- b. SDLC does not use a CRC
- c. DDCMP has a message header
- d. DDCMP does not require special hardware to find the beginning of a message
76. Which of the following transmission systems provides the highest data rate to an individual device?
- a. Voiceband modem
- b. Local area network
- c. Computer bus
- d. Digital PBX
77. Which of the following systems provides the longest digital transmission distances?
- a. Voiceband modem
- b. Local area network
- c. Computer bus
- d. Digital PBX
78. Which of the following is a characteristic of a LAN?
- a. Parallel transmission
- b. Unlimited expansion
- c. Low cost access for low bandwidth channels
- d. Application independent interfaces
79. Which of the following transmission media is not readily suitable to CSMA operation?
- a. Radio
- b. Optical fibers
- c. Coaxial cable
- d. Twisted pair
80. Which of the following functions is not provided as part of the basic Ethernet design?
- a. Access control
- b. Addressing
- c. Automatic retransmission of a message
- d. Multiple virtual networks
81. Which of the following is not a useful property of a Manchester line code for an Ethernet?
- a. Continuous energy
- b. Continuous clock transmissions
- c. No dc component
- d. No signal change at a 1 to 0 transition
82. Which of the following data communications functions is generally provided for in a LAN?
- a. Data link control
- b. Applications processing
- c. Flow control
- d. Routing
83. The purpose of a preamble in an Ethernet is
- a. Clock synchronization
- b. Error checking
- c. Collision avoidance
- d. Broadcast
84. Which of the following is possible in a token-passing bus network?
- a. Unlimited number of stations
- b. Unlimited distances
- c. Multiple time division channels
- d. In-service expansion
85. Which of the following is not possible in a token-passing loop network?
- a. Unlimited number of stations
- b. Unlimited distances
- c. Multiple time division channels
- d. In-service expansion
86. Which of the following LAN architectures can be expanded to the greatest total system bandwidth?
- a. Digital PBX
- b. CSMA/CD baseband system
- c. Token-passing network
- d. Broadband cable system
87. Which of the following systems is the most capable of servicing a wide range of applications?
- a. Digital PBX
- b. CSMA/CD baseband system
- c. Token-passing network
- d. Broadband cable system
88. Which of the following cannot be provided in a broadband LAN?
- a. Frequency agile modems
- b. Closed-circuit TV
- c. Voice circuits
- d. Fiber optics transmission
89. Which of the following is not possible in a digital PBX using twisted pair transmission?
- a. Computer port concentration
- b. 64-kbps data circuits
- c. High-speed file transfers
- d. Transmission up to several thousand feet
90. Which of the following is not a motivation in digitizing a voice signal in the telephones of a digital PBX?
- a. Simplified control signalling
- b. Lower cost telephones
- c. Fewer wire pairs
- d. Multiplexed voice and data channels
91. The electrical state of the control leads in a serial interface is a concern of
- a. The physical layer protocol
- b. The data link-layer protocol
- c. The network-layer protocol
- d. None of the above
92. The X.25 standard specifies a
- a. Technique for dial access
- b. Technique for start-stop data
- c. Data bit rate
- d. DTE/DCE interface
93. The X.25 standard is
- a. Required for all packet switching networks
- b. A recommendation of the CCITT
- c. A complete description of a public data network
- d. Used by all packet terminals
94. A protocol is a set of rules governing a time sequence of events that must take place
- a. Between peers
- b. Between nonpeers
- c. Across an interface
- d. None of the above
95. The X.25 standard for packet networks is analogous to
- a. PBX standards for a telephone network
- b. Handset standards for a telephone
- c. Local loop standards for a telephone network
- d. Switching standards for a telephone network
96. The OSI reference model defines the functions for seven layers of protocols
- a. Including the user and communications medium
- b. Not including the user or communications medium
- c. Including the communications medium but not the user
- d. Including the user but not the communications medium
97. The X.25 standard covers how many OSI layers?
- a. Three
- b. Four
- c. Seven
- d. None
98. A data packet is a packet header together with
- a. A network layer
- b. An administrative layer
- c. User data
- d. A packet switch
99. The X.25 standard specifies how many separate protocol layers at the serial interface gateway?
- a. 8
- b. 2
- c. 4
- d. 3
100. In X.25 network layer protocol, the data packets normally contain
- a. One octet of header plus data
- b. Two octets of header plus data
- c. Three octets of header plus data
- d. Four octets of header plus data
