NTS NAT-ICS (Computer Science Track) computer science Data Communication — Set 3

NTS NAT-ICS (Computer Science Track) computer science Data Communication — Set 3

1. Question 1

   Q1. In a Stop-and-Wait protocol, what happens when a packet is lost?

   • A) Sender retransmits
   • B) Receiver retransmits
   • C) Packet is discarded
   • D) Connection is terminated

   Answer: Sender retransmits

   Explanation: In Stop-and-Wait, the sender retransmits the packet if it doesn't receive an ACK within a certain time frame.

2. Question 2

   Q2. What is the purpose of the Time To Live (TTL) field in IP packets?

   • A) Preventing infinite loops
   • B) Ensuring packet delivery
   • C) Prioritizing packets
   • D) Authenticating packets

   Answer: Preventing infinite loops

   Explanation: TTL prevents packets from circulating indefinitely by decrementing the value at each hop until it reaches 0.

3. Question 3

   Q3. What is the primary difference between half-duplex and full-duplex communication?

   • A) Data rate
   • B) Transmission direction
   • C) Error detection
   • D) Flow control

   Answer: Transmission direction

   Explanation: Half-duplex allows transmission in both directions, but not simultaneously, while full-duplex allows simultaneous transmission.

4. Question 4

   Q4. What is the primary advantage of using UDP over TCP?

   • A) Guaranteed delivery
   • B) Lower overhead
   • C) Flow control
   • D) Error detection

   Answer: Lower overhead

   Explanation: UDP has lower overhead due to its connectionless nature and lack of acknowledgment mechanisms.

5. Question 5

   Q5. Which protocol is used for dynamically assigning IP addresses?

   • A) DHCP
   • B) DNS
   • C) ARP
   • D) RARP

   Answer: DHCP

   Explanation: DHCP dynamically assigns IP addresses to devices on a network, simplifying network configuration.

6. Question 6

   Q6. What is the primary function of the DNS protocol?

   • A) Resolving IP to domain names
   • B) Resolving domain names to IP
   • C) Routing packets
   • D) Error detection

   Answer: Resolving domain names to IP

   Explanation: DNS resolves domain names to IP addresses, enabling users to access websites using easy-to-remember names.

7. Question 7

   Q7. In a network, what is the purpose of the default gateway?

   • A) Routing packets within the network
   • B) Routing packets outside the network
   • C) Providing DNS services
   • D) Providing DHCP services

   Answer: Routing packets outside the network

   Explanation: The default gateway routes packets from a local network to external networks, such as the internet.

8. Question 8

   Q8. What is the primary purpose of the ICMP protocol?

   • A) Error reporting
   • B) Flow control
   • C) Routing
   • D) Address resolution

   Answer: Error reporting

   Explanation: ICMP is used for error reporting and diagnostic functions, such as ping and traceroute.

9. Question 9

   Q9. Which of the following is a type of transmission media?

   • A) Coaxial cable
   • B) Router
   • C) Switch
   • D) Hub

   Answer: Coaxial cable

   Explanation: Coaxial cable is a type of transmission media used for carrying data signals.

10. Question 10

    Q10. Which protocol is used for error detection in Data Communication?

    • A) TCP
    • B) UDP
    • C) CRC
    • D) ARP

    Answer: CRC

    Explanation: CRC (Cyclic Redundancy Check) is a protocol used for error detection by calculating a checksum for data packets.

11. Question 11

    Q11. What is the function of the Presentation Layer in the OSI model?

    • A) Data compression and encryption
    • B) Routing data between nodes
    • C) Providing network services to applications
    • D) Defining physical means of data transmission

    Answer: Data compression and encryption

    Explanation: The Presentation Layer is responsible for data compression, encryption, and formatting. NET computer science MCQs often test this core concept.

12. Question 12

    Q12. In a network, what is the primary function of a bridge?

    • A) Connecting multiple networks
    • B) Segmenting a network into smaller sub-networks
    • C) Providing network services to applications
    • D) Routing data between nodes

    Answer: Segmenting a network into smaller sub-networks

    Explanation: A bridge segments a network into smaller sub-networks, improving performance and reducing collisions.

13. Question 13

    Q13. A packet is transmitted from a sender to a receiver with a propagation delay of 50 ms and transmission delay of 20 ms. What is the total delay?

    • A) 70 ms
    • B) 50 ms
    • C) 20 ms
    • D) 100 ms

    Answer: 70 ms

    Explanation: Total delay = propagation delay + transmission delay = 50 ms + 20 ms = 70 ms.

14. Question 14

    Q14. What is the primary advantage of using a hub in a network?

    • A) Improved security
    • B) Increased data rate
    • C) Simplified network topology
    • D) Reduced collisions

    Answer: Simplified network topology

    Explanation: A hub simplifies network topology by connecting multiple devices to a single point.

15. Question 15

    Q15. What is the function of the Data Link Layer in the OSI model?

    • A) Providing network services to applications
    • B) Defining physical means of data transmission
    • C) Error detection and correction
    • D) Routing data between nodes

    Answer: Error detection and correction

    Explanation: The Data Link Layer is responsible for error detection and correction, as well as framing and flow control.

16. Question 16

    Q16. A channel has a data rate of 1000 bps and a packet size of 1000 bits. What is the transmission delay?

    • A) 1 s
    • B) 0.1 s
    • C) 10 s
    • D) 100 s

    Answer: 1 s

    Explanation: Transmission delay = packet size / data rate = 1000 bits / 1000 bps = 1 s.

17. Question 17

    Q17. What is the primary disadvantage of using a bus topology?

    • A) Difficulty in adding new devices
    • B) Single point of failure
    • C) Limited data rate
    • D) Increased collisions

    Answer: Single point of failure

    Explanation: A bus topology has a single point of failure, as a break in the backbone cable can bring down the entire network.

18. Question 18

    Q18. In a network, what is the primary function of a router?

    • A) Connecting multiple networks
    • B) Segmenting a network into smaller sub-networks
    • C) Providing network services to applications
    • D) Routing data between nodes

    Answer: Routing data between nodes

    Explanation: A router routes data between nodes, connecting multiple networks and determining the best path.

19. Question 19

    Q19. What is the purpose of the SYN flag in TCP?

    • A) To acknowledge receipt of data
    • B) To request retransmission of data
    • C) To establish a connection
    • D) To terminate a connection

    Answer: To establish a connection

    Explanation: The SYN flag is used to establish a connection, initiating the three-way handshake.

20. Question 20

    Q20. What is the primary advantage of using a ring topology?

    • A) Improved fault tolerance
    • B) Increased data rate
    • C) Simplified network topology
    • D) Reduced collisions

    Answer: Improved fault tolerance

    Explanation: A ring topology can be made fault-tolerant by using a dual-ring configuration, allowing data to be transmitted in both directions.