MCQ in Data Communications Part 1 | ECE Board Exam

This is the Multiple Choice Questions in Data Communications Part 1 of the Series as one of the Electronics Systems and Technologies Examination 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 Exam Questions in Electronics Systems and Technologies scope, Electronics Communications Books, Journals and other Electronics Communications References.

MCQ Topic Outline included in ECE Board Exam Syllabi

6. Data Communications

• MCQ in Introduction to Data Communications
• MCQ in Category of Data Communication
• MCQ in Configurations and Network Topology
• MCQ in Transmission Modes
• MCQ in Two-wire vs. Four-Wire Circuits
• MCQ in Types of Synchronization
• MCQ in Network Components (Terminal, multiplexer, concentrators)
• MCQ in Network Components (LCU, FEP, Serial Interface)
• MCQ in Security and Cryptography
• MCQ in Open System Interconnection
• MCQ in System Network Architecture
• MCQ in TCP/IP Architecture
• MCQ in Character-Oriented Protocols
• MCQ in Bit-Oriented Protocols
• MCQ in LAN, MAN, WAN, GAN
• MCQ in ISDN. B-ISDN

Start Practice Exam Test Questions Part 1 of the Series

Choose the letter of the best answer in each questions.

1. Telecommunications equipment that is located on the customer’s end (physical location) rather than on the provider’s premises or in between. This includes telephone handsets, modems, cable TV set-top boxes, and digital subscriber line routers.

A. POP

B. ISP

C. CPE

D. NAP

2. Which topology describes the way the data flow from one computer to another within a computer network?

A. physical

B. logical

C. virtual

D. isolated

3. Which topology uses a single cable which connects all the including nodes?

A. star

B. bus

C. ring

D. mesh

4. In an Ethernet segment arranged in a mesh topology, how many physical channel links are interconnected across ten network devices?

A. 10

B. 36

C. 45

D. 9

5. Type of cable that connects similar data communication devices like PC to PC without the use of hubs

A. Straight through cables

B. Cross over cables

C. Roll over cables

D. Serial cable

6. In practical terms, parallel data transmission is sent:

A. over short distances only

B. over long distances

C. over any distances

D. over a coaxial cable

7. How long will it take to transfer the hexadecimal characters FACE to the receiving station using parallel transmission? Assuming each transfer is 1 ms.

A. 1 ms

B. 2 ms

C. 8 ms

D. 16 ms

8. In asynchronous transmission, the transmitter and receiver are:

A. frame-by-frame synchronized using the data bits

B. frame-by-frame synchronized using a common clock

C. frame-by-frame synchronized using the start and stop bits

D. not synchronized at all, hence the name “asynchronous”

9. In synchronous transmission of data, the frame can be described as ______.

A. same length as the asynchronous frame

B. longer than the asynchronous frame

C. shorter than the asynchronous frame

D. no fixed length

10. The standard that describes the physical/ data link communication between cable modems

A. DOCSIS

B. PPPoE

C. PPPoA

D. RFC 1483

11. This device is used to adapt physical interface on a Data Terminal Equipment mechanism to a transmission facility such as T1 or E1 and also responsible for timing.

A. Data Service Unit ( DSU)

B. modem

C. UART

D. Data multiplexer

12. Clear to send is a signal passed from the local modem to the local terminal when data port is ready to transmit data. It usually occurs in response to

A. Acknowledgement

B. Request to Send

C. Discovery request

D. Polling request

13. Which of the following is an asymmetric cryptography algorithm?

A. DES

B. 3DES

C. AES-256

D. RSA

14. What technology provides an isolated tunnel across a public network for sending and receiving data privately as if the computing devices were directly connected to the private network?

A. SD-WAN

B. MPLS

C. Metro-E

D. VPN

15. VPN technology uses two simultaneous techniques to guarantee the privacy of data across an organization

A. SSL and tunneling

B. IPSec and SSL

C. IPSec and tunneling

D. MPLS and SDWAN

16. In data and network security, what is refer to as the main goal or the model that guide policies for information security within an organization.

A. confidentiality, cryptography and nonrepudiation

B. confidentiality, encryption and decryption

C. confidentiality, integrity and availability

D. encryption, hashing and access

17. Which of the following malicious attacks is threatening availability?

A. replaying

B. modification

C. traffic analysis

D. denial of service

18. How many handshakes is needed to establish TCP communication between end points of a data facility?

A. one 2-way handshake

B. one 3-way handshake

C. two 2-way handshake

D. two 3-way handshake

19. Flow control is needed to prevent

A. bit errors

B. overflow of the sender buffer

C. overflow of the receiver buffer

D. collision between sender and receiver

20. In what OSI layer does the security protocol suite IPSec belong?

A. Application

B. Transport

C. Data Link

D. Network

21. An outsourcing company named Voice International uses Voice over IP( VoIP). The system sends UDP datagrams containing voice data between communicating hosts. When areas of the network become busy, some of the datagrams arrive at their destination out of order. What happens when this occurs?

A. UDP will send an ICMP information request message to the source host

B. UDP will pass the information in the datagrams up to the next OSI layer in order which they arrive

C. UDP will drop datagrams that arrive out of order

D. UDP will use sequence numbers in datagram headers to reassemble the data into the order which it was transmitted

22. The OSI layer that checks frames’ error and adds flag bits to it.

A. physical

B. data link

C. network

D. application

23. What OSI layer is responsible for providing services to the user?

A. Application

B. Network

C. Transport

D. Physical

24. What is the primary function of the transport layer in the OSI model?

A. providing encryption and decryption of data

B. ensure reliable delivery of data between end systems

C. establish and terminate connections between devices

D. define the physical characteristics of the network medium

25. Where does routing occur within the DoD TCP/IP reference model?

A. application

B. internet

C. network

D. transport

26. Which of the following IP address classes is deployed in multicast application?

A. Class A

B. Class B

C. Class C

D. Class D

27. What is the maximum number of IP addresses that can be assigned to hosts on a local subnet that uses the 255.255.255.224 subnet mask?

A. 14

B. 15

C. 16

D. 30

28. The network address of 172.16.0.0/19 provides how many subnets?

A. 7 subnets

B. 8 subnets

C. 14 subnets

D. 3 subnets

29. Which among the following data link layer protocol is a bit-oriented protocol used for pointto-point and multipoint communications and part of X.25 network?

A. SDLC

B. HDLC

C. PPP

D. SLIP – Serial Line Interface Protocol

30. What PPP protocol provides dynamic addressing, authentication, and multilink?

A. NCP

B. HDLC

C. LCP

D. X.25

31. Which among the following UTP cable can be used for Fast Ethernet and Gigabit Ethernet applications supporting data rate up to 1 Gbps

A. CAT2

B. CAT4

C. CAT5e

D. CAT6

32. CSMA/CD describes how Ethernet protocol regulates communication among connection points. It uses back-off algorithm for what purpose?

A. To determine re-transmit delay after collision

B. For collision detection

C. For finding the shortest path

D. For finding a spanning free

33. Which characteristic does not apply to ISDN Primary Rate Interface (PRI)?

A. PRI offers 20 B channels and 1 D channel

B. the D channel is 64 kbps

C. can carry data, voice, or video

D. can carry vendor-specific PBX features

34. Telecom Company is implementing dial-up services to enable remote-office employees to connect to a local network. The company uses multiple routed protocols, needs authentication of users connecting to the network and since some calls will be long distance, needs callback support. Which of the following protocols is the best choice for remote service?

A. PPP

B. Frame Relay

C. HDLC

D. ISDN

35. An E1 line can handle 32 multiplexed voice channels, what is the overhead rate?

A. 64 Kbps

B. 8 Kbps

C. 12 Kbps

D. 1544 Kbps

36. What is the maximum number of characters or symbols that can be represented by Unicode?

A. 2^16 characters or symbols

B. 2^32 characters or symbols

C. 2^64 characters or symbols

D. 2^8 characters or symbols

37. A color image uses 16 bits to represent a pixel. What is the maximum number of different colors that can be represented?

A. 2^24 colors

B. 2^8 colors

C. 2^16 colors

D. 2^12 colors

38. Assume six devices are arranged in a mesh topology. How many cables are needed? How many ports are needed for each device?

A. 10 cables, 7 ports

B. 20 cables, 3 ports

C. 12 cables, 8 ports

D. 15 cables, 5 ports

39. A device is sending out data at the rate of 1000 bps. How long does it take to send a file of 100,000 characters?

A. 200 sec

B. 800 sec

C. 600 sec

D. 400 sec

40. We measure the performance of a telephone line (4 KHz of bandwidth). When the signal is 10 V, the noise is 5 mV. What is the maximum data rate supported by this telephone line?

A. 56.12 Kbps

B. 38.45 Kbps

C. 43.87 Kbps

D. 50.98 Kbps

41. A computer monitor has a resolution of 1200 by 1000 pixels. If each pixel uses 1024 colors, how many bits are needed to send the complete contents of a screen?

A. 15 Million Bits

B. 12 Million Bits

C. 8 Million Bits

D. 10 Million Bits

42. A signal travels from point A to point B. At point A, the signal power is 100 W. At point B, the power is 90 W. What is the attenuation in decibels?

A. 1.25 dB

B. -0.46 dB

C. 0.88 dB

D. -1.35 dB

43. The attenuation of a signal is -10 dB. What is the final signal power if it was originally 5 W?

A. 2.3 W

B. 0.1 W

C. 0.5 W

D. 1.75 W

44. If the bandwidth of the channel is 5 Kbps, how long does it take to send a frame of 100,000 bits out of this device?

A. 5 s

B. 50 s

C. 100 s

D. 20 s

45. The light of the sun takes approximately eight minutes to reach the earth. What is the distance between the sun and the earth?

A. 72 million km

B. 144 million km

C. 216 million km

D. 288 million km

46. A signal has a wavelength of 1 µm in air. How far can the front of the wave travel during 1000 periods?

A. 0.1 mm

B. 2 mm

C. 1 mm

D. 5 mm

47. A line has a signal-to-noise ratio of 1000 and a bandwidth of 4000 KHz. What is the maximum data rate supported by this line?

A. 52.43 Mbps

B. 18.75 Mbps

C. 39.87 Mbps

D. 27.61 Mbps

48. A file contains 2 million bytes. How long does it take to download this file using a 56-Kbps channel?

A. 340.8 s

B. 285.7 s

C. 298.5 s

D. 259.4 s

49. A signal with 200 milliwatts power passes through 10 devices, each with an average noise of 2 microwatts. What is the SNR? What is the SNRdB?

A. 5,000, 37 dB

B. 10,000, 40 dB

C. 15,000, 42 dB

D. 20,000, 43 dB

50. If the peak voltage value of a signal is 20 times the peak voltage value of the noise, what is the SNR? What is the SNRdB?

A. 600, 27.78 dB

B. 400, 26.02 dB

C. 800, 29.03 dB

D. 200, 23.01 dB

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