Computer Network Multiple Choice Questions

Computer Network Multiple Choice Questions

1) Which of these is a standard interface for serial data transmission?

ASCII

RS232C

2

Centronics 

Answer: (b) RS232C

Explanation: The RS232C is a standard interface for serial data transmission that defines the protocol and physical interface for transmitting serial data fairly easily between associated appliances and computers.

2) Which type of topology is best suited for large businesses which must carefully control and coordinate the operation of distributed branch outlets?

Ring

Local area

Hierarchical

Star 

Answer: (d) Star

Explanation: The star topology is the best network topology for large businesses because it is simple to control and coordinate from the central computer.

3) Which of the following transmission directions listed is not a legitimate channel?

Simplex

Half Duplex

Full Duplex

Double Duplex 

Answer: (d) Double Duplex

Explanation: Double duplex is not a legitimate channel for transmission in computer network.

4) "Parity bits" are used for which of the following purposes?

Encryption of data

To transmit faster

To detect errors

To identify the user 

Answer: (c) To detect errors

Explanation: The parity bit is also known as the check bit, and has a value of 0 or 1. It is used for error detection for blocks of data.

5) What kind of transmission medium is most appropriate to carry data in a computer network that is exposed to electrical interferences?

Unshielded twisted pair

Optical fiber

Coaxial cable

Microwave 

Answer: (b) Optical fiber

Explanation: The optical fiber is made of glass or plastic. In this cable, the transmission of data occurs in the form of light rather than the electric current, so this cable provides higher data transfer speed than other cables.

6) A collection of hyperlinked documents on the internet forms the ?.?

World Wide Web (WWW)

E-mail system

Mailing list

Hypertext markup language 

Answer: (a) World Wide Web (WWW)

Explanation: World Wide Web (WWW) creates a collection of hyperlinked documents on the Internet.

7) The location of a resource on the internet is given by its?

Protocol

URL

E-mail address

ICQ 

Answer: (b) URL

Explanation: A URL (Uniform Resource Locator) is a database connection that describes the database's location on a computer network and the retrieval process. A URL is a different form of URI (Uniform Resource Identifier) although the two words are used interchangeably by many people.

8) The term HTTP stands for?

Hyper terminal tracing program

Hypertext tracing protocol

Hypertext transfer protocol

Hypertext transfer program 

Answer: (c) Hypertext transfer protocol

Explanation: The term HTTP stands for Hypertext transfer protocol.

9) A proxy server is used as the computer?

with external access

acting as a backup

performing file handling

accessing user permissions 

Answer: (a) with external access

Explanation: A proxy server is a computer that acts as a gateway between a user's computer and the Internet. The proxy server is also called application level gateway. By this the client computer can establish indirect network connection to another network.

10) Which one of the following would breach the integrity of a system?

Looking the room to prevent theft

Full access rights for all users

Fitting the system with an anti-theft device

Protecting the device against willful or accidental damage 

Answer: (b) Full access rights for all users

Explanation: None

11) Which software prevents the external access to a system?

Firewall

Gateway

Router

Virus checker 

Answer: (a) Firewall

Explanation: A firewall is a network securing software that prevents unauthorized users and dangerous elements from accessing the network. Software firewall acts as a filter for our network which prevents harmful information.

12) Which one of the following is a valid email address?

javat@point.com

gmail.com

tpoint@.com

javatpoint@books 

Answer: (a) javat@point.com

Explanation: A proper email address is a combination of the email prefix and email domain, both in appropriate formats. The domain appears to the right side of the @ symbol and the prefix appears to the left side of the @ symbol.

For example, in this email address javat@point.com, "javat" is the prefix, and "point.com" is the domain.

13) Which of the following best describes uploading information?

Sorting data on a disk drive

Sending information to a host computer

Receiving information from a host computer

Sorting data on a hard drive 

Answer: (b) Sending information to a host computer

Explanation: None

14) Which one of the following is the most common internet protocol?

HTML

NetBEUI

TCP/IP

IPX/SPX 

Answer: (c) TCP/IP

Explanation: TCP/IP is the most common internet protocol because it is the most widely used network protocol.

15) Software programs that allow you to legally copy files and give them away at no cost are called which of the following?

Probe ware

Timeshare

Shareware

Public domain 

Answer: (d) Public domain

Explanation: Public domain software can be modified, distributed or sold by anyone without any attention, but no one can ever own it.

16) The term FTP stands for?

File transfer program

File transmission protocol

File transfer protocol

File transfer protection 

Answer: (c) File transfer protocol

Explanation: The term FTP stands for File transfer protocol.

17) At what speed does tele-computed refer?

Interface speed

Cycles per second

Baud rate

Megabyte load 

Answer: (c) Baud rate

Explanation: In telecommunication, baud rate is a specific unit of the speed rate. It is one of the significant functions that determine the speed of the communication over the data channel.

18) Which one of the following is not a network topology?

Star

Ring

Bus

Peer to Peer 

Answer: (d) Peer to Peer

Explanation: Peer to Peer network is a network to which all computers are used the same resources and rights as other computers. Its network designed primarily for the small local area.

19) The maximum length (in bytes) of an IPv4 datagram is?

32

1024

65535

512 

Answer: (c) 65535

Explanation: None

20) Which of the following statements could be valid with respect to the ICMP (Internet Control Message Protocol)?

It reports all errors which occur during transmission.

A redirect message is used when a router notices that a packet seems to have been routed wrongly.

It informs routers when an incorrect path has been taken.

The "destination unreachable" type message is used when a router cannot locate the destination. 

Answer: (b) A redirect message is used when a router notices that a packet seems to have been routed wrongly.

Explanation: None

21) The IP network 192.168.50.0 is to be divided into 10 equal sized subnets. Which of the following subnet masks can be used for the above requirement?

255.243.240

255.255.0.0

255.255.0

255.255.255 

Answer: (c) 255.255.255.0

Explanation: This address belongs to class C, so 8 bits are reserved for the host ID. 24 bits are reserved for network ID.

22) When the mail server sends mail to other mail servers it becomes ___ ?

SMTP client

SMTP server

Peer

Master 

Answer: (a) SMTP client

Explanation: The SMTP client is an organization that allows sending emails using the SMTP server. SMTP servers can't send emails to other SMTP servers separately. It is based on client-server architecture.

23) The length of an IPv6 address is?

32 bits

64 bits

128 bits

256 bits 

Answer: (c) 128 bits

Explanation: An IPv6 address is 128 bits long, which has 2^128 address space.

24) Consider the following:

Twisted pair cables

Microwaves and Satellite Signals

Repeaters

Analog Transmissions

Fiber optics

Which of the above is consider as (a) signal transmission medium is data communications?

(1) and (5)

(1) and (2)

(1) (2) and (5)

(1) (2) (3) and (5) 

Answer: (c) (1) (2) and (5)

Explanation: None

25) Which of the following address belongs class A?

121.12.12.248

130.12.12.248

128.12.12.248

129.12.12.248 

Answer: (a) 121.12.12.248

Explanation: 121.12.12.248 address belongs the class A because the first octet value of this address lies between 0 and 127.

26) Which of the following is correct IPv4 address?

124.201.3.1.52

01.200.128.123

300.142.210.64

10110011.32.16.8

128.64.0.0 

Answer: (e) 128.64.0.0

Explanation: 128.64.0.0 is correct IPv4 address because IPv4 is a standard numbering system that uses four integers from 0 to 255. The IP address is a group of numbers that identify user system on the network.

27) Which of the following IP addresses can be used as (a) loop-back addresses?

0.0.0.0

127.0.0.1

255.255.255.255

0.255.255.255 

Answer: (b) 127.0.0.1

Explanation: A loopback address is a special IP address whose IP address is between 127.0.0.1 to 127.255.255.255. It is reserved for loopback. It doesn't require a physical connection to a network.

28) The term WAN stands for?

Wide Area Net

Wide Access Network

Wide Area Network

Wide Access Net 

Answer: (c) Wide Area Network

Explanation: The term WAN stands for Wide Area Network.

29) Which of the following cannot be used as a medium for 802.3 ethernet?

A thin coaxial cable

A twisted pair cable

A microwave link

A fiber optical cable 

Answer: (c) A microwave link

Explanation: A microwave link cannot be used as a medium for 802.3 ethernets, because a microwave link is a transmission network that utilizes a beam of radio waves in the microwave frequency spectrum to relay video, audio, or data between two places.

30) What IP address class allocates 8 bits for the host identification part?

Class A

Class B

Class C

Class D 

Answer: (c) Class C

Explanation: In class C only, 8 bits are reserved for the host ID, and 24 bits are reserved for network ID.

31) The term IANA stands for?

Internet Assigned Numbers Authority

Internal Assigned Numbers Authority

Internet Associative Numbers Authoritative

Internal Associative Numbers Authority 

Answer: (a) Internet Assigned Numbers Authority

Explanation: The term IANA stands for Internet Assigned Numbers Authority.

32) How many versions available of IP?

6 version

4 version

2 version

1 version 

Answer: (c) 2 version

Explanation: There are only two IP versions are avilable in the present: IP version 4 (IPv4) and IP version 6 (IPv6).

33) Which layer of the TCP / IP stack corresponds to the OSI model transport layer?

Host to host

Application

Internet

Network Access 

Answer: (a) Host to Host

Explanation: The host to host layer conforms the transport layer of the OSI model. This layer is responsible for the final correspondence and error-free distribution of data.

34) An Aloha network uses an 18.2 kbps channel for sending message packets of 100 bits long size. Calculate the maximum throughput.

5999

6900

6027

5027 

Answer: (c) 0.6027

Explanation: In Pure Aloha, Efficiency = 18.4%

Usable bandwidth for 18.2 kbps = 18.2 * 0.18 = 3.276 kbps

Therefore, the maximum throughput of Pure Aloha

= 1/2e * 3.276

= (18.4 * 3.276) / 100

= 0.6027

35) On a simplex data link, which of the following is a possible error recovery technique?

Backward error correction (BEC)

The use of hamming codes

Automatic Repeat Request (ARQ)

Downward error correction (DEC) 

Answer: (b) The use of hamming codes

Explanation: The hamming codes is an error recovery technique that can be used to detect and correct the errors. It was developed by R.W. Hamming.

36) Which of the statement is correct with regard to Time Division Multiplexing (TDM) and its variants?

Statistical TDM makes efficient use of the bandwidth only if the arrival pattern of the data stream is probabilistic.

TDM requires the transmitter and receiver to be synchronized periodically.

TDM performs efficiently if the arrival pattern of the data stream is probabilistic.

Statistical TDM is efficient if the data stream is deterministic. 

Answer: (a) and (b)

Explanation: None

37) The term IPv4 stands for?

Internet Protocol Version 4

Internet Programming Version 4

International Programming Version 4

None of these 

Answer: (a) Internet Protocol Version 4

Explanation: The term IPv4 stands for Internet Protocol Version 4.

38) The term LAN stands for?

Local Area Net

Local Aera Network

Local Array Network

Local Array Net 

Answer: (b) Local Area Network

Explanation: The term LAN stands for Local Area Network.

39) Which of the through is share the data of two computer?

Library

Network

Grouping

Integrated system 

Answer: (b) Network

Explanation: There are many ways to share data between two computers, but a network connection is established before data sharing.

40) In specific, if the systems use separate protocols, which one of the following devices is used to link two systems?

Repeater

Gateway

Bridge

Hub 

Answer: (b) Gateway

Explanation: If the system used separate protocols, gateway device is used to link two systems.

41) How many digits of the Data Network Identification Code (DNIC) identify the country?

first three

first four

first five

first six

None of the above 

Answer: (a) first three

Explanation: The first three digits of the Data Network Identification Code (DNIC) is identify the country (first digit to identify a zone and other two digits to identify the country within the zone).

42) Which of the following methods is used to broadcast two packets on the medium at a time?

Collision

Synchronous

Asynchronous

None of the above 

Answer: (a) Collision

Explanation: A collision occurs when two or more computers are attempting to transfer data across a network at a time.

43) Which of the following is true with regard to the ping command?

Ping stands for Packet Internet Generator.

The ping command checks the port level connectivity between source destinations end points.

Ping summarizes the packet loss and round-trip delay between two IP end points.

The ping command activates the RARP protocol of the IP layer. 

Answer: (c) Ping summarizes the packet loss and round-trip delay between two IP end points.

Explanation: None

44) The private key in asymmetric key cryptography is kept by?

Sender

Receiver

Sender and Receiver

None of the these 

Answer: (b) Receiver

Explanation: Only the receiver keeps the private key. Its purpose is to ensure that the message can only be decrypted by the intended receiver.

45) Which of the following algorithms is not used in asymmetric-key cryptography?

RSA algorithm

Diffie-Hellman algorithm

Electronic code book algorithm

None of the mentioned 

Answer: (c) Electronic code book algorithm

Explanation: An electronic code book algorithm is a mode of operation for a block cipher, where each frame of text in an encrypted document refers to a data field. In other terms, the same plaintext value would also give the same value for ciphertext.

46) In the cryptography, the sequence of the letters is rearranged by?

Transposition ciphers

Substitution ciphers

Both a and b

None of these 

Answer: (a) Transposition ciphers

Explanation: A predefined technique shuffles the sequence of letters in a plaintext message in the transposition ciphers.

47) What is the maximum efficiency of pure aloha at G = 1/2?

1.89

17.99

18.999

18.4 

Answer: (d) 18.4

Explanation: The maximum efficiency of pure aloha formula is G * e-2G.

Given, G =1/2

=1/2 x e-2 x 1/2

= 1 / 2e

= 0.184

= 18.4%

48) What is the maximum efficiency of slotted aloha at G = 1?

36.8

35.8

35.5

37.8 

Answer: (a) 36.8

Explanation: The maximum efficiency of slotted aloha formula is G * e-G.

Given, G = 1

= 1 x e-1

= 1 / e

= 0.368

= 36.8%

49) Which of the following statement is true about error detection techniques used on communications link?

Cyclic Redundancy Check (CRC) sequence can detect as well as correct errors.

Error detection cannot be used on simplex links.

Hamming code can detect up to 3-bit errors.

All of the these 

Answer: (d) All of the these

Explanation: None

50) The correct order of corresponding OSI layers for having functionalities of routing and reconciling machine representation differences with shared access resolution and ASCII test protocol is?

Network, Physical, Transport, Data link

Network, Physical, Data link, Application

Network, Presentation, Data link, Application

Network, Presentation, Physical, Transport 

Answer: (c) Network, Presentation, Data link, Application

Explanation: None