MCQ in Digital and Data Communication Networks Part 2 | ECE Board

This is the Multiple 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.

MCQ Topic Outline included in ECE Board Exam Syllabi

• MCQ in Bit and and Binary Transmission
• MCQ in Signaling Rate
• MCQ in Error Probability, Digital Filtering, Switching, Packet Circuit, Vertical Circuit
• MCQ in Open systems Interconnection
• MCQ in Multiplying, Modulation and Synchronization
• MCQ in Pulse Code Modulation, Companding, Encoding, Bandwidth and Signal to Noise Ratio
• MCQ in Delta Modulation, Slope Overload, Adaptive Delta Modulation, Codes and Protocol
• MCQ in Error Detection and Correction, Digital Carrier systems
• MCQ in Frequency Shift Keying, Phase Shift Keying, Differential Phase Shift keying
• MCQ in DC nature of data transmission, loops, Neutral and Polar
• MCQ in Binary transmission and the concept of time
• MCQ in Asynchronous and Synchronous, timing, Distortion, Bits, band, WPM
• MCQ in Data Interface standards, Data input/output devices
• MCQ in Digital Transmission on analog channel, Modulation-demodulation schemes parameters
• MCQ in Circuit conditioning, Modem Applications
• MCQ in Serial and Parallel Transmission

Continue Practice Exam Test Questions Part 2 of the Series

⇐ MCQ in Digital and Data Communication Networks Part 1 | ECE Board

Choose the letter of the best answer in each questions.

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

d. none of these

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. Voice band 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 non-peers

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

Questions and Answers in Digital and Data Communication Networks Series

Following is the list of multiple choice questions in this brand new series:

Complete List of MCQ in Communications Engineering per topic