In the name of ALLAH, the most beneficient, the most merciful

Data Communication (CS601)

Multiple Choice Questions (MCQs)

Objective Questions

  1. What is the frequency of a sine wave if it completes one cycle in 5 seconds?

    1. 0.5
    2. 0.6
    3. 0.3
    4. 0.2
  2. At the Application layer, object/information is in the form of ________.

    1. Message
    2. Packet
    3. Segment
    4. Frame
  3. Possession of TOKEN gives the station the right to ________.

    1. Modify the data
    2. Send the data
    3. Delete the data
    4. Receive the data
  4. What is the frequency of a sine wave if it completes one cycle in 2 seconds?

    1. 0.5
    2. 0.6
    3. 0.3
    4. 0.2
  5. Terminal, microprocessor, computer, printer or any other device that generates or consumes digital data is known as ___________

    1. DCE
    2. DTE
    3. DCE & DTE
    4. None of the given
  6. VCI address is ________ address in virtual circuit approach.

    1. Private
    2. Variable
    3. Local
    4. Global
  7. In ASK correct formula for calculating the bandwidth ia as ________.

    1. B=(1+d)S
    2. B=(1*d)S
    3. B=(d-1)S
    4. B=(d-5)S
  8. RZ stands for ___________.

    1. Return to Z
    2. Retire a Zero
    3. Return ot Zero
    4. None of the given
  9. WDM stands for _________.

    1. Wave Division Multiplexing
    2. Wrong Division Multiplexing
    3. Well Division Multiplexing
    4. West Division Multiplexing
  10. Asynchronous TDM is efficient only when the size of the time slot is kept relatively ___________.

    1. Large
    2. Small
    3. Medium
    4. Zero
  11. There are ________ basic categories of multiplexing.

    1. 2
    2. 3
    3. 7
    4. 5
  12. The __________ generates the data and passes it along with any control information to a __________.

    1. DTE, DCE
    2. DCE, DTE
    3. DTE, DTE
    4. DCE, DCE
  13. In Block coding scheme, number of code words is always ________ data words.

    1. Less than
    2. Equal to
    3. Greater than
    4. Same as
  14. In ________, each station is allocated a time slot during which it can send data.

    1. CDMA
    2. NDMA
    3. TDMA
    4. FDMA
  15. Two or more computers connected so that they can communicate with each other and share information is called a ___________.

    1. satellite
    2. protocol
    3. broadcast
    4. network
  16. Checksum is an error-detection technique that can be applied to a message of ________ length.

    1. Exactly 4
    2. Exactly 8
    3. Exactly 32
    4. Any
  17. If a digital signal has "L" number of levels. ________ is the number of bits required to represent each level.

    1. Log L
    2. Log Base 2 L
    3. L Square
    4. Log(2*L)
  18. In CSMA/CA, ________ is the amount of time divided into slots.

    1. Interframe Window
    2. Contention Window
    3. Fragmented Window
    4. Collided Window
  19. Latency is made of ________ components.

    1. Two
    2. Three
    3. Four
    4. Five
  20. Low pass channel has ________ bandwidth between two stations.

    1. Dedicated
    2. Shared
    3. Multiplexed
    4. Infinite
  21. In Block coding we divide our message into blocks of k bits called as ________.

    1. Code words
    2. Data words
    3. Passwords
    4. Cross words
  22. Time domain shows changes in ___________.

    1. time w.r.t signal amplitude
    2. signal amplitude w.r.t time
    3. time
    4. All of the given
  23. Session layer is responsible for _________.

    1. Reassembly of data
    2. Maintaining the connection
  24. Which of the following is not a characteristic of a sine wave?

    1. Amplitude
    2. Segmentation
    3. Phase
    4. Frequency
  25. Central Hub in a Tree is an ___________.

    1. Active hub
    2. passive hub
  26. Data Link layer provides services to the ________ layer.

    1. Application
    2. Transport
    3. Network
    4. Session
  27. Each computer on the Internet has a unique numeric address called a(n) ___________.

    1. domain address
    2. protocol address
    3. IP address
    4. Web address
  28. S-frames in High-Level Data Link Control (HDLC) are only used to transfer ________ information.

    1. User data
    2. Control
    3. Redundant
    4. Original
  29. A sine wave is ___________.

    1. periodic and discrete
    2. aperiodic and discrete
    3. periodic and continuous
    4. aperiodic and continuous
  30. Which of the following sublyer resolves the contention for the shared media.

    1. MAC
    2. LLC
    3. Physical
    4. None of the given.
  31. Normally the value of Kmax in pure ALOHA is ________.

    1. 25
    2. 10
    3. 15
    4. 30
  32. TROPOSHERE is the layer of atmosphere above the troposhere but below space

    1. True
    2. False
  33. Traditionally MANs have been implemented using one of the 2 technologies, Circuit Switching and Packet Switching

    1. true
    2. false
  34. A sine wave is defined by ___________ characteristics.

    1. 2
    2. 3
    3. 4
    4. 5
  35. A fiber -optic cable transmit signals in the form of ________.

    1. Light
    2. Sound
    3. Wave
    4. None of the given
  36. ________ are used to exchange session management and control information between connected devices.

    1. I-frames
    2. U-frames
    3. S-frames
    4. N-frames
  37. Like Data link layer, ___________ is also responsible for Flow control.

    1. Transport Layer
    2. Session Layer
  38. A ________ modem is used to connect two DTEs directly.

    1. 'NULL
    2. Cable
    3. DSL
    4. None of the given
  39. Digital signals are refered to be ___________.

    1. Continuous
    2. Discrete
    3. All of the given
    4. None of the given
  40. The message 1110 sent by a source is received by a destination as 1011. This is ________ type of error.

    1. Burst
    2. Single-Bit
    3. Uni-Bit
    4. Hamming
  41. To make sure that source does not overwhelm destination by sending data faster than it can be handled and processed is called?

    1. Addressing & Routing
    2. Exchange Management
    3. Flow Control
    4. Recovery
  42. Like 10 Base 5, 10 Base 2 is a ________ topology LAN.

    1. Ring
    2. Mesh
    3. Star
    4. Bus
  43. No matter whether the link is dedicated or broadcast, data link control (DLC) layer provides services between ________.

    1. Virtual LANs
    2. Two adjacent nodes
    3. Ethernet links
    4. Source and destination PCs
  44. CDMA stands for ________.

    1. Carrier Division Multiple Access
    2. Carrier Data Multiple Access
    3. Code Data Multiple Access
    4. Code Division Multiple Access
  45. ________ is sometimes called the bit rate.

    1. signal rate
    2. modulation rate
    3. Data rate
    4. pulse rate
  46. There are three types of Hubs that exist. Which of the following options correctly describes these three?

    1. Passive, dormant, special
    2. Active , dormant , passive
    3. Passive, Active, Turbo
    4. Passive, Active, Intelligent
  47. Asynchronous transmission is ___________.

    1. Slow
    2. Fast
    3. Costly
    4. None effective
  48. ________ contains a repeater.

    1. Active hub
    2. Passive hub
  49. The extra bits added with the original data for error detection/correction are called ________.

    1. Fault bits
    2. Port numbers
    3. Redundant bits
    4. Process IDs
  50. The original Ethernet technology with the data rate of 10 Mbps is called ________?

    1. Standard Ethernet
    2. Fast Ethernet
    3. Gigabit Ethernet
    4. 10 Gigabit Ethernet
  51. ________ is responsible for governing node to node communication.

    1. Application Layer
    2. Session Layer
    3. Data Link layer
    4. Presentation Layer
  52. ________ is not a function of Data Link Control.

    1. Framing
    2. Modulation
    3. Error Control
    4. Flow Control
  53. PSK is susceptible to the noise degradation.

    1. True
    2. False
  54. To calculate the data rate for noisy channel ________ formula is used.

    1. Shannon
    2. Nyquist
    3. Propagation
    4. Greedy
  55. Is there any difference between Data communication and telecommunication are network?

    1. Yes
    2. No
  56. What is the period of a Sine wave having frequency of 5 Hz?

    1. 0.2
    2. 0.1
    3. 0.5
    4. 0.3
  57. ________ signal can take infinite levels of intensity over time.

    1. Digital
    2. Discrete
    3. Analog
    4. Logical
  58. If duration of noise is decreased during a transmission over noisy channel, fixed data rate of the channel will cause ________ number of bits being impacted by the noise.

    1. Constant
    2. More
    3. Less
    4. Zero
  59. Guard bands are used in ________ multiplexing technique, to avoid overlapping of frequency bands assigned to each user.

    1. PDM
    2. CSMA
    3. TDM
    4. FDM
  60. A portion of the path that carries TX between a given pair of devices is known as ___________.

    1. Direct Point
    2. Bridge
    3. Channel
    4. Access Point
  61. dB is negative if a signal is ___________.

    1. Attenuated
    2. Distorted
    3. Amplified
    4. Noisy
  62. Mr. Asif while sitting in Lahore is talking with his friend in Dubai through Skype is an example of ________.

    1. Local Area Network
    2. Metropolitan Area Network
    3. Wide Area Network
    4. Home Based Network
  63. In circuit switched networks we have low efficiency but minimal ________.

    1. Delay
    2. Speed
    3. Throughput
    4. Errors
  64. ________ of a signal is the collection of all the component frequencies it contains.

    1. Time domain
    2. Frequency domain
    3. Frequency spectrum
    4. None of the given
  65. The inversion of the level represents a 1 bit in ______ encoding

    1. NRZ-I
    2. NRZ-L
    3. RZ
    4. Manchester
  66. In Pulse Code Modulation (PCM), the sampling is dependent on ________.

    1. Time
    2. Amplitude
    3. Frequency
    4. Signal Rate
  67. Which error detection method uses one's complement arithmetic.

    1. Cyclic Redundancy Check (CRC)
    2. Longitudinal Red Check (LRC)
    3. Checksum
    4. Simple Parity Check
  68. BSC supports ___________ transmission using ___________ flow control.

    1. Full-duplex, Stop and wait ARQ
    2. Half-duplex, Selective reject ARQ
    3. Full-duplex, Selective reject ARQ
    4. Half-duplex, Stop and wait ARQ
  69. To control and manage the transfer of data, a protocol called Point to Point Protocol (PPP) is used at the ________ layer.

    1. Physical
    2. Network
    3. Presentation
    4. Data link
  70. At the CRC generator, ___________ added to the data unit before the divisional process.

    1. 0s are
    2. 1s are
    3. a polynomial is
    4. a CRC remainder is
  71. What was the main draw back in ALOHA Random-Access method?

    1. Redundancy in Data
    2. Potential Collision
    3. Inconsistent Data rate
    4. All of the given
  72. The type of ALOHA which improves the efficiency of Pure ALOHA is ________.

    1. Slotted ALOHA
    2. Upper ALOHA
    3. Integrated ALOHA
    4. Lower ALOHA
  73. In OSI model headers are added at layer _________.

    1. 1,2,3 only
    2. 6,5,7 only
    3. 5,4,3 only
    4. 6,5,4,3,2 only
  74. Flow control is needed to prevent ________.

    1. Bit errors
    2. Overflow of the sender buffer
    3. Overflow of the receiver buffer
    4. Collision between sender and receiver
  75. What is the Bandwidth of a periodic signal if it is decomposed into 4 sine waves with frequencies 200, 400, 600 and 800?

    1. 100
    2. 500
    3. 300
    4. 600
  76. ________ is the rate of change with respect to time.

    1. Voltage
    2. Time
    3. Frequency
    4. Amplitude
  77. AM signal requires ___________ the BW of original signal

    1. Twice
    2. Half
    3. Same
    4. Three Times
  78. In an analog hierarchy to carry voice channels, a group can carry ________ voice channels.

    1. 60
    2. 12
    3. 20
    4. 10
  79. Encoding digital data into digital signals is called ___________.

    1. Analog-to-Digital Conversion
    2. Digital-to-Digital Conversion
    3. Digital-to-Analog Conversion
    4. None of the given
  80. In line discipline after the data transmission, the sending system finishes with an ________ frame.

    1. EOT
    2. EKT
    3. ENT
    4. ESP
  81. CHAP is an Authentication Protocol, which uses ________ process to authenticate user information.

    1. Two-way
    2. Three-way
    3. Four-way
    4. Five-way
  82. There are __________types of guided media.

    1. 2
    2. 3
    3. 4
    4. 5
  83. ________ category of coaxial cable is used for Cable TV.

    1. RG-58
    2. RG-59
    3. RG-11
    4. RG-47
  84. A broadcast signal is received by the orbiting satellites which rebroadcasts ________.

    1. to the resender
    2. to the sender
    3. to the atmosphere
    4. none of the given
  85. Quantization is a method of assigning ________ values in a specific range to sampled instances.

    1. Negative
    2. Positive
    3. Binary
    4. Integral
  86. In ________, both peak amplitude and frequency remains constant as the phase changes.

    1. PSK
    2. QAM
    3. Both PSK & QAM
    4. None of the given
  87. The logical connection between the peer layers is ________ connection.

    1. Physical
    2. Direct
    3. Indirect
    4. Tengible
  88. If the window size is 63 in go-back N ARQ then what is the range of sequence number?

    1. 0 to 63
    2. 0 to 64
    3. 1 to 63
    4. 1 to 64
  89. Signals travel through fiber optic cable are in the form of ________.

    1. Light
    2. Bits
    3. Electromagnetic
    4. Bytes
  90. The most common type of connector used by coaxial cable is ________.

    1. BNC
    2. RJ-45
    3. RJ-11
    4. RJ-57
  91. The inversion of the level at 1 bit is called as ________.

    1. NRZ-L
    2. NRZ-I
    3. RZ
    4. None of the given.
  92. Line Configuration refers to the way two or more devices attach to a ___________.

    1. Path
    2. Circuit
    3. Link
    4. Router
  93. STP is more expensive than UTP and is less susceptible to noise.

    1. True
    2. False
  94. ________ is used in the Stop-and-Wait protocol to overcome the issue of duplication.

    1. Frame sequencing
    2. Acknowledgement numbering
    3. Counter and Timer reset
    4. Frame sequencing and Acknowledgement numbering
  95. If we need to correct a single error in an 8-bit data unit, we need to consider ________ possible error locations.

    1. 16
    2. 2
    3. 4
    4. 8
  96. Digitizing an Analog Signal is called ___________.

    1. Analog-to-Digital Conversion
    2. Digital-to-Digital Conversion
    3. Digital-to-Analog Conversion
    4. None of the given
  97. Which of the following is most affected by noise?

    1. PSK
    2. ASK
    3. FSK
    4. QAM
  98. In Pure ALOHA, the vulnerable time is ________ the frame transmission time.

    1. Same as
    2. Two times
    3. Three times
    4. Four times
  99. The flag in PPP is a byte that needs to be ________ whenever it appears in the data section of the frame.

    1. Duplicated
    2. Blocked
    3. Cleaned
    4. Escaped
  100. Which error detection method consists of a parity bit for each unit as well as an entire data unit of parity bits?

    1. Checksum
    2. Cyclic Redundancy Check (CRC)
    3. Longitudinal Red Check (LRC)
    4. Vertical Redundancy Check (VRC)
  101. Error correction is more ________ than the error detection.

    1. Easy
    2. Useless
    3. Informal
    4. Difficult
  102. Switch is a network device which operates on the ________ layer of the TCP/IP protocol suite.

    1. Application
    2. Transport
    3. Presentation
    4. Data link
  103. In _________, a signal is directed straight from antenna to antenna.

    1. Line of sight propagation
    2. Ground propagation
    3. Space propagation
    4. Tropospheric propagation
  104. GO-BACK-N protocol is one of the ________ layer protocols, which is used to control the flow of data during the transmission.

    1. Physical
    2. Network
    3. Presentation
    4. Data link
  105. In ________ each band is reserved for a specific ststion, and it belongs to the station all the time.

    1. FDMA
    2. CDMA
    3. TDMA
    4. CSMA
  106. What is the period of a Sine wave having frequency of 10 Hz?

    1. 0.2
    2. 0.1
    3. 0.5
    4. 0.3
  107. Which one of the following is not a Channelization Protocol?

    1. FDMA
    2. CSMA
    3. CDMA
    4. TDMA
  108. ________ is correct formula to determine the total number of ports needed for one system connected in a mesh network.

    1. N+1
    2. N-1
    3. N(N+1)
    4. NxN
  109. Which one of the following is a correct-access method?

    1. Polling
    2. Token Passing
    3. Reservation
    4. All of the given
  110. The logical connection between the peer layers is ________ connection.

    1. Physical
    2. Direct
    3. Indirect
    4. Tangible
  111. In the ________ method, the stations in a network are orgamized in a logical ring.

    1. Token-passing
    2. Polling
    3. Reservation
    4. None of the given
  112. At the CRC checker, ___________ means that the data unit is damaged.

    1. A string of 0s
    2. A string of 1s
    3. A string of alternating 1s and 0s
    4. A nonzero remainder
  113. Which level of the TCP/IP reference model routes data/information across a network channel?

    1. Application Layer
    2. Data Link Layer
    3. Transport Layer
    4. Network Layer
  114. Sampling means measuring ____________ of signal at equal intervals

    1. Amplitudes
    2. Frequencies
    3. Phases
    4. None of the given
  115. The flag in PPP is a byte that needs to be ________ whenever it appears in the data section of the frame.

    1. Duplicated
    2. Blocked
    3. Cleaned
    4. Escaped
  116. Time domain plot show changes in signal phase with respect to time.

    1. true
    2. false
  117. In ___________ a dedicated communication path is established between two stations through the nodes of the network

    1. Circuit switching
    2. Packet switching
  118. Which of the following consist of just one redundant bit per data unit?

    1. Two dimentional Parity check.
    2. CRC
    3. Simple Parity Check
    4. Checksum
  119. In even parity check code, the value of syndrome is ________ if the number of 1s is even.

    1. 1
    2. 2
    3. 0
    4. 4
  120. Which one of the following is a Random-Access protocol?

    1. TDMA
    2. CDMA/CD
    3. ALOHA
    4. CDMA/CA
  121. Transmission Control Protocol is a(n) ________ layer protocol.

    1. Transport
    2. Application
    3. Session
    4. Network
  122. ________ mode of serial transmission guarantees fixed rate of data.

    1. Synchronous
    2. Asynchronous
    3. Isochronous
    4. Metasochronous
  123. Error detection and correction are the services provided by ________ layer.

    1. Data link layer
    2. Application layer
    3. Physical layer
    4. Session layer
  124. In Synchronous TDM, Time slots are not same in number as input devices.

    1. True
    2. False
  125. ________ is an Authentication Protocol, which is used by the PPP to authenticate passwords.

    1. CHAP
    2. PAP
    3. LCP
    4. ICMP
  126. We can have ________ different groups with a 4 bit block.

    1. 4
    2. 8
    3. 16
    4. 32
  127. DLC in Data Link Layer stands for ________.

    1. Divide Line Communication
    2. Data Line Code
    3. Data Link Control
    4. Demand Link Coordination
  128. What is the period of a Sine wave having frequency of 2 Hz?

    1. 0.2
    2. 0.1
    3. 0.5
    4. 0.3
  129. In TCP/IP protocol suite, the process of adding header at each layer on sending side is known as ________.

    1. Encapulation
    2. De-encapulation
    3. Packetizing
    4. Framing
  130. Quadrature Amplitude Modulation (QAM) is the combination of ________ and ________.

    1. FSK, PSK
    2. PSK, FSK
    3. ASK, PSK
    4. ASK, FSK
  131. Which of the following statement is correct?

    1. Digital signals are less prone to Noise
    2. Digital signals are highly prone to Noise
    3. Analog Signals are less prone to Noise
    4. Digital signals are not affected by Noise
  132. Human voice is example of ___________ signal.

    1. Digital
    2. Analog
    3. Discrete
    4. None of the given
  133. In Pure ALOHA, the vulnerable time is ________ the frame transmission time.

    1. Same as
    2. Three times
    3. Two times
    4. Four times
  134. In statistical time division multiplexing, number of slots in frame are less than ________.

    1. Output data rate
    2. Input lines
    3. Input frequency
    4. Multiplexed T lines
  135. Data is transmitted using light through a ___________ cable.

    1. twisted pair
    2. fiber-optic
    3. coaxial
    4. microwave
  136. In frequency shift keying, ________ remain(s) constant.

    1. Frequency
    2. Amplitude
    3. Both Amplitude and Phase
    4. Both Phase and Frequency
  137. The level of signal is always positive in NRZ encoding.

    1. true
    2. false
  138. Analog To Analog Conversion Methods include ___________.

    1. AM, PM and FM
    2. AM, FSK and PM
    3. AM, PM and QAM
    4. None of the given
  139. ________ is normally used where speed is priority in data transfer.

    1. Serial data transmission
    2. Hybrid data transmission
    3. Parallel data transmission
    4. Both parallel and serial data transmission
  140. There are _________ types of serial transmission.

    1. 3
    2. 4
    3. 2
    4. None of the given
  141. If the Hamming distance between sent and received code word is ________, then it shows that received data is corrupted.

    1. ≠ 0
    2. = 0
    3. ≠ 1
    4. = 1
  142. Radio is an example of _______ signal conversion.

    1. Analog to analog
    2. Analog to digital
    3. Digital to Digital
    4. Digital to analog
  143. The ________ is the number of signal elements sent per unit time.

    1. Data rate
    2. Signal rate
    3. Bit rate
    4. Period
  144. ________ works with topologies in which one drvice is designated as a primary station and the other devices are secondary stations.

    1. Reservation
    2. Polling
    3. Token
    4. None of the given
  145. The transmission medium that carries the message is referred to as the ___________.

    1. send and receive device
    2. communication channel
    3. protocol
    4. gateways
  146. The term _______means that only one bit of a given data unit is changed from 1 to 0 or from 0 to 1.

    1. Packet Error
    2. Burst Error
    3. Single Bit Error
    4. Character Error
  147. In which controlled-access method all data exchanges must be made through primary device even when the ultimate destination is a secondary device?

    1. Polling
    2. Reservation
    3. Token Passing
    4. Port Forwarding
  148. Analog refers to something that is continuous in ___________.

    1. Time
    2. Space
    3. Frequency
    4. None of the given
  149. ________ is the process of converting digital data to digital signals.

    1. CSMA/CD
    2. CSMA/CA
    3. Line coding
    4. Segmentation
  150. In the encoding where positive to negative transition is one and vice versa is zero.

    1. Manchester
    2. Differential Manchester
    3. All of the given
    4. None of given
  151. In ASK, both ______ and ________ remain constant.

    1. Amplitude, Frequency
    2. Amplitude, phase
    3. Frequency, Phase
    4. Amplitude, Samples
  152. Collisions in CSMA/CA are avoided through ________.

    1. The Interframe Space
    2. The Contention Window
    3. Acknowledgements
    4. All of the given
  153. In selective-reject ARQ, only the specific damaged or lost frame is ________.

    1. Retransmitted
    2. Forwarded
    3. Selected
    4. Rejected
  154. ________ category of coaxial cable is used for thin Ethernet.

    1. RG-58
    2. RG-59
    3. RG-1
    4. RG-47
  155. In CRC there is no error if the remainder at the receiver is _______.

    1. Equal to the remainder at the sender
    2. Zero
    3. Nonzero
    4. The quotient at the sender
  156. In ________, each station sends a frame whenever it has a frame to send.

    1. Slotted ALOHA
    2. Fragmented ALOHA
    3. Pure ALOHA
    4. None of the given
  157. ________ relatively measures the strength of two signals.

    1. Signal rate
    2. Bit rate
    3. Decibel
    4. Pulse Rate
  158. ________ is/are un-reliable protocol(s).

    1. IP and TCP
    2. UDP
    3. IP and UDP
    4. TCP
  159. WDM stands for ________.

    1. Wideband De-Modulation
    2. Worst Data Manipulation
    3. Wavelength Division Multiplexing
    4. None of the given
  160. If users must take turns using the link, then it is called Spatial Sharing.

    1. true
    2. false
  161. In analog transmission, the base signal is called the________.

    1. Carrier Signal
    2. Analog signal
    3. Digital signal
    4. Modulated signal
  162. Congestion Control is a feature of layer(s).

    1. Data Link
    2. Network
    3. Transport
    4. All mentioned
  163. Radio wave transmission utilizes ___________ different types of propagation.

    1. Two
    2. Three
    3. Four
    4. Five
  164. Which layer is concerned with the syntax and semantics of info exchange between two systems?

    1. Physical
    2. Application
    3. Session
    4. Presentation
  165. The Internet is ___________.

    1. software for sending e-mail around the world
    2. a government-owned agency that links computers
    3. a global network of computers networks
    4. a specialised form of local area network
  166. What is the Bandwidth of a periodic signal if it is decomposed into 4 sine waves with frequencies 300, 600, 900 and 1200?

    1. 100
    2. 900
    3. 300
    4. 600
  167. YMODEM has ________ Byte of data unit.

    1. 1024
    2. 256
    3. 128
    4. 512
  168. ________ encoding is almost obsolete today

    1. Bipolar
    2. Unipolar
    3. Polar
    4. None of the given
  169. POST stand for ________?

    1. Plain Old Telephone Set
    2. Plain Old Time Sharing
    3. Plain Old Telephone System
    4. Plain Old Telephone Service
  170. Time division multiplexing is used in ________ systems.

    1. Analog
    2. Hybrid
    3. Digital
    4. Automated
  171. Baud rate is greater than or equal to the bit rate.

    1. True
    2. False
  172. Following characteristics fully describe ___________,
    Amplitude
    Period/Frequency
    Phase

    1. Sine Waves
    2. Digital Signals
    3. Aperiodic Signals
    4. None of the given
  173. The ________ protocol uses both flow and error control.

    1. TCP/IP
    2. HDLC
    3. ICMP
    4. Stop-and-Wait
  174. ________ transmission technology (based on Ethernet) provides a data rate of 1 billion bits per second.

    1. Fast Ethernet
    2. Standard Ethernet
    3. Gigabit Ethernet
    4. 10BASE-T Ethernet
  175. ________ is an Authentication Protocol, which uses two-step process to authenticate user information.

    1. CHAP
    2. LCP
    3. PAP
    4. ICMP
  176. In order to find the location of two errors in an eight bit stream, we have to see ________ different combinations.

    1. 28
    2. 16
    3. 8
    4. 4
  177. Analog signals are refers to be ___________

    1. Continuous
    2. Discrete
    3. Periodic
    4. Aperiodic
  178. Which one is not the function of data link layer?

    1. Line discipline
    2. Flow control
    3. Error control
    4. Network control
  179. In ASK, Noise usually affects the ________.

    1. Amplitude
    2. Phase
    3. Sample
    4. Frequency
  180. By using ___________ system, change in the file contents during file transmission can be avoided.

    1. Routing
    2. Flow Control
    3. Error Detection and Correction
    4. Congestion Control