Data Communication -MCQs with Answers.(BE-3/4)

1. ______ refers to the physical or logical arrangement of a network.

§  A) Topology

§  B) Mode of operation

§  C) Data flow

§  D) None of the above

2. A ________ is a set of rules that governs data communication.

§  A) protocol

§  B) forum

§  C) standard

§  D) none of the above

3. Data flow between two devices can occur in a _______ way.

§  A) simplex

§  B) half-duplex

§  C) full-duplex

§  D) all of the above

4. The process-to-process delivery of the entire message is the responsibility of the _______ layer.

§  A)   Transport

§  B)   Application

§  C)   Physical

§  D)   Network

5.  The_____ address identifies a process on a host.

§  A)   specific

§  B)   port

§  C)   IP

§  D)   physical

6. The TCP/IP _______ layer is equivalent to the combined session, presentation, and application layers of the OSI model.

§  A)   data link

§  B)   network

§  C)   physical

§  D)   application

7. When a host on network A sends a message to a host on network B, which address does the router look at?

§  A)   logical

§  B)   physical

§  C)   port

§  D)   none of the above

8. Ethernet uses a ______ physical address that is imprinted on the network interface card (NIC).

§  A)   32-bit

§  B)   6-byte

§  C)   64-bit

§  D)   none of the above

9. TCP/IP is a ______ hierarchical protocol suite developed ____ the OSI model.

§  A)   five-layer; before

§  B)   six-layer; before

§  C)   seven-layer; before

§  D)   five-layer; after

10.  _________ can impair a signal.

§  A)   Noise

§  B)   Attenuation

§  C)   Distortion

§  D)   All of the above

11.  ________ is a type of transmission impairment in which the signal loses strength due to the resistance of the transmission medium.

§  A)   Distortion

§  B)   Attenuation

§  C)   Noise

§  D)   Decibel

12.  ________ is a type of transmission impairment in which the signal loses strength due to the different propagation speeds of each frequency that makes up the signal.

§  A)   Noise

§  B)   Distortion

§  C)   Attenuation

§  D)   Decibel

13.  For a ______ channel, we need to use the Shannon capacity to find the maximum bit rate.

§  A)   noiseless

§  B)   noisy

§  C)   low-pass

§  D)   bandpass

14.  ______ substitutes eight consecutive zeros with 000VB0VB.

§  A)   B4B8

§  B)   B8ZS

§  C)   HDB3

§  D)   none of the above

15. The most common technique to change an analog signal to digital data is called __________.

§  A)   sampling

§  B)   PAL

§  C)   PCM

§  D)   none of the above

16. 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

17. The signal rate is sometimes called the ____ rate.

§  A)   bit

§  B)   baud

§  C)   signal

§  D)   none of the above

18. Unipolar, bipolar, and polar encoding are types of _______ encoding.

§  A)   line

§  B)   block

§  C)   NRZ

§  D)   Manchester

19. 14. 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

20. 15. Quadrature amplitude modulation (QAM) is a combination of ___________.

§  A)   PSK and FSK

§  B)   ASK and FSK

§  C)   ASK and PSK

§  D)   none of the above

21. In QAM, both ________ of a carrier frequency are varied.

§  A)   phase and frequency

§  B)   amplitude and phase

§  C)   frequency and amplitude

§  D)   none of the above

22. The sharing of a medium and its link by two or more devices is called _______.

§  A)   modulation

§  B)   multiplexing

§  C)   encoding

§  D)   line discipline

23.  _______ is designed to be used in wireless applications in which stations must be able to share the medium without interception by an eavesdropper and without being subject to jamming from a malicious intruder.

§  A)   Multiplexing

§  B)   Spread spectrum

§  C)   Modulation

§  D)   None of the above.

24.  _________ are used for cellular phone, satellite, and wireless LAN communications.

§  A)   Radio waves

§  B)   Infrared waves

§  C)   Microwaves

§  D)   none of the above

25. Transmission media are usually categorized as ___________.

§  A)   determinate or indeterminate

§  B)   fixed or unfixed

§  C)   guided or unguided

§  D)   metallic or nonmetallic

26.  _________ media transport electromagnetic waves without the use of a physical conductor.

§  A)   Guided

§  B)   Unguided

§  C)   Either (a) or (b)

§  D)   None of the above

27.  Which of the following primarily uses guided media?

§  A)   radio broadcasting

§  B)   satellite communications

§  C)   local telephone system

§  D)   cellular telephone system

28. When a beam of light travels through media of two different densities, if the angle of incidence is greater than the critical angle, _______ occurs.

§  A)   refraction

§  B)   reflection

§  C)   criticism

§  D)   incidence

29.  Microwaves are _________.

§  A)   omnidirectional

§  B)   bidirectional

§  C)   unidirectional

§  D)   none of the above

30. Radio waves are _________.

§  A)   unidirectional

§  B)   omnidirectional

§  C)   bidirectional

§  D)   none of the above

31. In a fiber-optic cable, the signal is propagated along the inner core by __________.

§  A)   refraction

§  B)   reflection

§  C)   modulation

§  D)   none of the above

32. 1. Packet-switched networks can also be divided into _________ subcategories: virtual-circuit networks and datagram networks.

§  A)   five

§  B)   three

§  C)   two

§  D)   four

33. 2. In __________, each packet is treated independently of all others.

§  A)   circuit switching

§  B)   datagram switching

§  C)   frame switching

§  D)   none of the above

33. In _______ switching, the paths in the circuit are separated from one another spatially.

§  A)   time-division

§  B)   two-dimensional

§  C)   space-division

§  D)   three-dimensional

34. A ________ network is made of a set of switches connected by physical links, in which each link is divided into n channels.

§  A)   circuit-switched

§  B)   line-switched

§  C)   frame-switched

§  D)   none of the above

35. A _________ network is a cross between a circuit-switched network and a datagram network. It has some characteristics of both.

§  A)   packet-switched

§  B)   frame-switched

§  C)   virtual-circuit

§  D)   none of the above

36. Circuit switching takes place at the ________ layer.

§  A)   physical

§  B)   data line

§  C)   network

§  D)   transport

37.  A ________ switch combines crossbar switches in several (normally three) stages.

§  A)   multiple path

§  B)   multiple crossbar

§  C)   multistage

§  D)   none of the above

 38. A ________ switch is a multistage switch with micro switches at each stage that route the packets based on the output port represented as a binary string.

§  A)   TSI

§  B)   banyan

§  C)   crossbar

§  D)   none of the above

39. In cyclic redundancy checking, the divisor is _______ the CRC.

§  A)   one bit less than

§  B)   one bit more than

§  C)   The same size as

§  D)   none of the above

40. In cyclic redundancy checking, what is the CRC?

§  A)   The quotient

§  B)   The dividend

§  C)   The divisor

§  D)   The remainder

41. A _____ error means that two or more bits in the data unit have changed.

§  A)   burst

§  B)   double-bit

§  C)   single-bit

§  D)   none of the above

42. HDLC is an acronym for _______.

§  A)   Half-duplex digital link combination

§  B)   Host double-level circuit

§  C)   High-duplex line communication

§  D)   High-level data link control

43.  _______ control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgment.

§  A)   Flow

§  B)   Error

§  C)   Transmission

§  D)   none of the above

44. High-level Data Link Control (HDLC) is a _______ protocol for communication over point-to-point and multipoint links.

§  A)   byte-oriented

§  B)   bit-oriented

§  C)   character-oriented

§  D)   none of the above

45. Bit stuffing means adding an extra 0 to the data section of the frame when there is a sequence of bits with the same pattern as the ________.

§  A)   trailer

§  B)   flag

§  C)   header

§  D)   none of the above

46. In the _________ method, after the station finds the line idle, it sends its frame immediately. If the line is not idle, it continuously senses the line until it finds it idle.

A)   p-persistent

B)   nonpersistent

C)   1-persistent

D)   none of the above

47. The vulnerable time for CSMA is the ________propagation time.

A)   three times

B)   two times

C)   the same as

D)   none of the above

48. The maximum throughput for pure ALOHA is ________ per cent.

A)   36.8

B)   18.4

C)   12.2

D)   none of the above

49. 13. In ___________ methods, no station is superior to another station and none is assigned the control over another.

A)   controlled access

B)   random access

C)   channelization

D)   none of the above

50. In the ________method, a station that has a frame to send senses the line. If the line is idle, it sends immediately. If the line is not idle, it waits a random amount of time and then senses the line again.

A)   1-persistent

B)   non-persistent

C)   p-persistent

D)   none of the above

51. In the _______method, after the station finds the line idle it sends or refrain from sending based on the outcome of a random number generator. If the line is busy, it tries again.

A)   p-persistent

B)   nonpersistent

C)   1-persistent

D)   none of the above

52. In _______, collisions are avoided through the use of three strategies: the interframe space, the contention window, and acknowledgments.

A)   CSMA/CD

B)   CSMA/CA

C)   either (a) or (b)

D)   both (a) and (b)

53.  __________ uses thin coaxial cable.

A)   10Base2

B)   10Base5

C)   10Base-F

D)   10Base-T

54. Standard Ethernet (10-Mbps) uses _______ encoding.

A)   AMI

B)   Manchester

C)   NRZ

D)   differential Manchester

55. Gigabit Ethernet access methods include _______ mode.

A)   full-duplex

B)   half-duplex

C)   both (a) and (b)

D)   neither (a) nor (b)

56. In Ethernet addressing, if the least significant bit of the first byte is 1, the address is _________.

A)   multicast

B)   broadcast

C)   unicast

D)   none of the above

57.  _______ is the most widely used local area network protocol.

A)   Token Bus

B)   Ethernet

C)   Token Ring

D)   none of the above

58.  The _____ sublayer is responsible for the operation of the CSMA/CD access method and framing.

A)   MAC

B)   MII

C)   LLC

D)   none of the above

59.  ______defines a protocol data unit (PDU) that is somewhat similar to that of HDLC.

A)   LLC

B)   LLU

C)   MAC

D)   none of the above

60. The original IEEE 802.11, has a data rate of ________ Mbps.

A)   11

B)   22

C)   6

D)   1

61. In IEEE 802.11, when a frame is going from one station in a BSS to another without passing through the distribution system, the address flag is _________.

A)   11

B)   00

C)   10

D)   01

62. In IEEE 802.11, the access method used in the PCF sublayer is ______.

A)   polling

B)   controlled

C)   contention

D)   none of the above

63. In IEEE 802.11, a BSS without an AP is called an _________.

A)   an infrastructure network

B)   an ad hoc architecture

C)   either (a) or (b)

D)   neither (a) nor (b)

64. In IEEE 802.11, the addressing mechanism can include up to ______addresses.

A)   six

B)   five

C)   four

D)   none of the above

65. In Bluetooth, the _______ layer is roughly equivalent to the physical layer of the Internet model.

A)   baseband

B)   radio

C)   L2CAP

D)   none of the above

66. In IEEE 802.11, a station with ________ mobility is either stationary (not moving) or moving only inside a BSS.

A)   ESS-transition

B)   no-transition

C)   BSS-transition

D)   none of the above

67.  A Bluetooth network is called a ________.

A)   scatternet

B)   bluenet

C)   piconet

D)   none of the above

68. A Bluetooth network consists of _____ primary device(s) and up to ____ secondary devices.

A)   one; seven

B)   one; five

C)   five; three

D)   two; six

69. Bluetooth uses ______method in the physical layer to avoid interference from other devices or other networks.

A)   FHSS

B)   DSSS

C)   FDMA

D)   none of the above

70. n Bluetooth, the _____layer is roughly equivalent to the MAC sublayer in LANs.

A)   L2CAP

B)   radio

C)   baseband

D)   none of the above

71. IEEE has defined the specifications for a wireless LAN, called _______, which covers the physical and data link layers.

A)   IEEE 802.5

B)   IEEE 802.11

C)   IEEE 802.2

D)   IEEE 802.3

72. In IEEE 802.11, the access method used in the DCF sublayer is _________.

A)   CSMA/CA

B)   CSMA/CD

C)   ALOHA

D)   none of the above

73.  A bridge can use the _________ algorithm to create a loopless topology.

A)   multiway tree

B)   binary tree

C)   spanning tree

D)   none of the above

74. A _______ can check the MAC addresses contained in the frame.

A)   repeater

B)   bridge

C)   router

D)   passive hub

75. A two-layer switch is a ______.

A)   router

B)   repeater

C)   bridge

D)   none of the above

76.  A ________receives a signal and, before it becomes too weak or corrupted, regenerates the original bit pattern. It then sends the refreshed signal.

A)   router

B)   bridge

C)   repeater

D)   passive hub

77.  A three-layer switch is a kind of ________.

A)   bridge

B)   router

C)   repeater

D)   none of the above

78. Some new two-layer switches, called _______ switches, have been designed to forward the frame as soon as they check the MAC addresses in the header of the frame.

A)   come-through

B)   go-through

C)   cut-through

D)   none of the above