Computer Network MCQs & Data Communication MCQs

Fiber optics possess following properties
(a) Immune electromagnetic interference
(b) Very less signal attenuation
(c) Very hard to tap
(d) All of the mentioned
Answer: d

If an Optical Carrier is represented as OC-n, generally the link speed equals (in Mbps),
(a) n*39.8
(b) n*51.8
(c) 2n*51.8
(d) none of the mentioned
Answer. b

Terrestrial radio channels are broadly classified into ______ groups.
(a) 2
(b) 3
(c) 4
(d) 1
Answer. b

Radio channels are attractive medium because
(a) Can penetrate walls
(b) Connectivity can be given to mobile user
(c) Can carry signals for long distance
(d) All of the mentioned
Answer. d

Geostationary satellites
(a) Are placed at a fixed point above the earth
(b) Rotate the earth about a fixed axis
(c) Rotate the earth about a varying axis
(d) All of the mentioned
Answer. a

The sharing of a medium and its link by two or more devices is called ______
(a) Fully duplexing
(b) Multiplexing
(c) Both a and b
(d) None of the mentioned
Answer. b

Multiplexing is used in ______
(a) Packet switching
(b) Circuit switching
(c) Data switching
(d) None of the mentioned
Answer. b

Which multiplexing technique transmits digital signals?
(a) FDM
(b) TDM
(c) WDM
(d) None of the mentioned
Answer. b

If there are n signal sources of same data rate than TDM link has ______slots
(a) n
(b) n/2
(c) n*2
(d) 2^n
Answer. a

If link transmits 4000frames per second, and each slot has 8 bits, the transmission rate of circuit this TDM is
(a) 32kbps
(b) 500bps
(c) 500kbps
(d) None of the mentioned
Answer. a

The state when dedicated signals are idle are called
(a) Death period
(b) Poison period
(c) Silent period
(d) None of the mentioned
Answer. c

Multiplexing can provide
(a) Efficiency
(b) Privacy
(c) Anti jamming
(d) Both a and b
Answer. d

In TDM, the transmission rate of the Multiplexed path is usually ______ the sum of the transmission rates of the signal sources.
(a) Greater than
(b) Lesser than
(c) Equal to
(d) Equal to or greater than
Answer. a

In TDM, slots are further divided into
(a) Seconds
(b) Frames
(c) Packets
(d) None of the mentioned
Answer. b

Multiplexing technique that shifts each signal to a different carrier frequency
(a) FDM
(b) TDM
(c) Either a or b
(d) Both a and b
Answer. a

Physical or logical arrangement of network is
(a) Topology
(b) Routing
(c) Networking
(d) None of the mentioned
Answer. a

In this topology there is a central controller or hub
(a) Star
(b) Mesh
(c) Ring
(d) Bus
Answer. a

This topology requires multipoint connection
(a) Star
(b) Mesh
(c) Ring
(d) Bus
Answer. d

Data communication system spanning states, countries, or the whole world is
(a) LAN
(b) WAN
(c) MAN
(d) None of the mentioned
Answer. a

Data communication system within a building or campus is
(a) LAN
(b) WAN
(c) MAN
(d) None of the mentioned
Answer. a

Expand WAN
(a) World area network
(b) Wide area network
(c) Web area network
(d) None of the mentioned
Answer. b

A local telephone network is an example of a ______ network
(a) Packet switched
(b) Circuit switched
(c) Both of the mentioned
(d) None of the mentioned
Answer. a

Most packet switches use this principle
(a) Stop and wait
(b) Store and forward
(c) Both of the mentioned
(d) None of the mentioned
Answer. b

If there are N routers from source to destination, total end to end delay in sending packet P (L->number of bits in the packet R-> transmission rate)
(a) N
(b) (N*L)/R
(c) (2N*L)/R
(d) L/R
Answer. b

Method(s) to move data through a network of links and switches
(a) Packet switching
(b) Circuit switching
(c) Line switching
(d) Both a and b
Answer. d

The resources needed for communication between end systems are reserved for the duration of session between end systems in ______
(a) Packet switching
(b) Circuit switching
(c) Line switching
(d) Frequency switching
Answer. b

As the resources are reserved between two communicating end systems in circuit switching, this is achieved
(a) authentication
(b) guaranteed constant rate
(c) reliability
(d) store and forward
Answer. b

In ______ resources are allocated on demand.
(a) packet switching
(b) circuit switching
(c) line switching
(d) frequency switching
Answer. a

What is internet?
(a) a single network
(b) a vast collection of different networks
(c) interconnection of local area networks
(d) none of the mentioned
Answer. b

To join the internet, the computer has to be connected to a
(a) internet architecture board
(b) internet society
(c) internet service provider
(d) none of the mentioned
Answer. c

Internet access by transmitting digital data over the wires of a local telephone network is provided by
(a) leased line
(b) digital subscriber line
(c) digital signal line
(d) none of the mentioned
Answer. b

ISP exchanges internet traffic between their networks by
(a) internet exchange point
(b) subscriber end point
(c) ISP end point
(d) none of the mentioned
Answer. a

Which one of the following protocol is not used in internet?
(a) HTTP
(b) DHCP
(c) DNS
(d) none of the mentioned
Answer. d

IPv6 addressed have a size of
(a) 32 bits
(b) 64 bits
(c) 128 bits
(d) 265 bits
Answer. c

Internet works on
(a) packet switching
(b) circuit switching
(c) both (a) and (b)
(d) none of the mentioned
Answer. a

Which one of the following is not an application layer protocol used in internet?
(a) remote procedure call
(b) internet relay chat
(c) resource reservation protocol
(d) none of the mentioned
Answer. c

Which protocol assigns IP address to the client connected in the internet?
(a) DHCP
(b) IP
(c) RPC
(d) none of the mentioned
Answer. a

Which one of the following is not used in media access control?
(a) Ethernet
(b) digital subscriber line
(c) fiber distributed data interface
(d) none of the mentioned
Answer. d

IPsec is designed to provide the security at the
(a) transport layer
(b) network layer
(c) application layer
(d) session layer
Answer. b

In tunnel mode IPsec protects the
(a) entire IP packet
(b) IP header
(c) IP payload
(d) none of the mentioned
Answer. a

Network layer firewall works as a
(a) frame filter
(b) packet filter
(c) both (a) and (b)
(d) none of the mentioned
Answer. b

Network layer firewall has two sub-categories as
(a) stateful firewall and stateless firewall
(b) bit oriented firewall and byte oriented firewall
(c) frame firewall and packet firewall
(d) none of the mentioned
Answer. a

WPA2 is used for security in
(a) Ethernet
(b) Bluetooth
(c) Wi-Fi
(d) none of the mentioned
Answer. c

An attempt to make a computer resource unavailable to its intended users is called
(a) denial-of-service attack
(b) virus attack
(c) worms attack
(d) botnet process
Answer. a

Extensible authentication protocol is authentication framework frequently used in
(a) wired personal area network
(b) wireless networks
(c) wired local area network
(d) none of the mentioned
Answer. b

Pretty good privacy (PGP) is used in
(a) browser security
(b) email security
(c) FTP security
(d) none of the mentioned
Answer. b

PGP encrypts data by using a block cipher called
(a) international data encryption algorithm
(b) private data encryption algorithm
(c) internet data encryption algorithm
(d) none of the mentioned
Answer. a

When a DNS server accepts and uses incorrect information from a host that has no authority giving that information, then it is called
(a) DNS lookup
(b) DNS hijacking
(c) DNS spoofing
(d) none of the mentioned
Answer. c

Which of the following delay is faced by the packet in travelling from one end system to another?
(a) Propagation delay
(b) Queuing delay
(c) Transmission delay
(d) All of the mentioned
Answer. d

For a 10Mbps Ethernet link, if the length of the packet is 32bits, the transmission delay is (in milliseconds)
(a) 3.2
(b) 32
(c) 0.32
(d) None of the mentioned
Answer. a