UGC NET Computer Science Unit 9 PYQs & Important Topics

Preparing for UGC NET Computer Science Unit 9 can be challenging because computer networks include several conceptual and numerical topics that are frequently asked in the examination. From OSI layers and TCP/IP protocols to subnetting and cryptography, candidates need a strong understanding of multiple concepts.

UGC NET Computer Science Unit 9 PYQs help candidates understand the exam pattern, identify high-weightage topics, and recognise repeatedly asked questions. Reviewing previous year questions can improve conceptual clarity and make preparation more focused and effective.

Why Are UGC NET Computer Science Unit 9 PYQs Important?

Previous year questions help candidates:

• Understand the latest exam pattern.

• Identify repeated concepts.

• Improve speed and accuracy.

• Practice numerical and conceptual questions.

• Build confidence before the examination.

Many topics from Unit 9 have appeared multiple times in previous examinations, making PYQ practice an essential part of preparation.

UGC NET Computer Science Unit 9 PYQs with Answers

Previous year questions help candidates understand the type of concepts frequently tested in Unit 9. The following questions are based on important topics discussed in computer networks and have appeared repeatedly in different forms.

Which layer is responsible for logical addressing?
Answer: Network Layer.

Which address is also known as a Hardware Address?
Answer: MAC Address.

Which communication type is provided by the Transport Layer?
Answer: Process-to-Process Communication.

Which communication type is associated with the Network Layer?
Answer: Host-to-Host Communication.

Which protocol is connection-oriented?
Answer: TCP.

Which protocol is connectionless?
Answer: UDP.

Which protocol is commonly used for video streaming applications?
Answer: UDP.

Which protocol dynamically assigns IP addresses to devices?
Answer: DHCP (Dynamic Host Configuration Protocol).

Which random access protocol allows users to transmit data randomly?
Answer: ALOHA.

Which bit-oriented protocol is used at the Data Link Layer?
Answer: HDLC (High-Level Data Link Control).

Which controlled access techniques are used in computer networks?
Answer: Reservation, Polling, and Token Passing.

Which address is formed by combining an IP address and a port number?
Answer: Socket Address.

Which cipher uses one-to-one mapping?
Answer: Monoalphabetic Cipher.

Which cipher uses one-to-many mapping?
Answer: Polyalphabetic Cipher.

How many rounds are used in the DES algorithm?
Answer: 16 rounds.

What is the key size used in DES?
Answer: 56 bits.

Which operation is commonly used in Stream Ciphers?
Answer: XOR operation.

Which wireless technology uses SIM cards?
Answer: GSM.

Which technology stands for Code Division Multiple Access?
Answer: CDMA.

Which layer is responsible for transmitting raw bits?
Answer: Physical Layer.

Which layer is responsible for framing?
Answer: Data Link Layer.

Which layer performs routing functions?
Answer: Network Layer.

Which layer creates segments?
Answer: Transport Layer.

What is the minimum Hamming Distance required to detect s errors?
Answer: s + 1.

What is the minimum Hamming Distance required to correct s errors?
Answer: 2s + 1.

What is the remainder obtained in CRC called?
Answer: CRC bits.

What is formed by combining the Dataword and CRC bits?
Answer: Codeword.

Which protocol provides flow control and congestion control?
Answer: TCP.

Which protocol does not provide retransmission mechanisms?
Answer: UDP.

Which header structures are most important for UGC NET Unit 9 preparation?
Answer: IPv4 Header, IPv6 Header, TCP Header, and UDP Header.

Important Topics Covered in Unit 9 Computer Networks

The following topics are frequently asked in UGC NET Computer Science:

OSI Layer Model

• Physical Layer

• Data Link Layer

• Network Layer

• Transport Layer

IP Addressing and Subnetting

• IP Classes (A, B, C, D, E)

• Subnet Masks

• Host Calculation

• Number of Subnets

Transport Layer Protocols

• TCP

• UDP

• Connection-Oriented Communication

• Connectionless Communication

Header Structures

• IPv4 Header

• IPv6 Header

• TCP Header

• UDP Header

Error Detection and Correction

• CRC (Cyclic Redundancy Check)

• Hamming Distance

• Hamming Code

Channel Access Protocols

• ALOHA

• CSMA

• Reservation Protocol

• HDLC

Cryptography

• Monoalphabetic Cipher

• Polyalphabetic Cipher

• DES

• Stream Cipher

Wireless Communication Technologies

• GSM

• CDMA

• UMTS

• Wi-Fi

Frequently Repeated Concepts in Unit 9

Several concepts are repeatedly asked in UGC NET examinations:

TCP vs UDP: Important Exam Topic

TCP and UDP are among the most frequently asked topics in the UGC NET Computer Science Unit 9. Candidates should clearly understand the differences between these transport layer protocols, as questions based on their features and applications are commonly asked in previous year examinations.

TCP is preferred when reliability is required, whereas UDP is suitable for applications where speed is more important than guaranteed delivery.

Numerical Topics Asked in Unit 9

Numerical questions are an important part of Unit 9 preparation. Candidates should understand formulas and practice calculations regularly, as topics like subnetting, CRC, Hamming Distance, and RSA have been asked repeatedly in previous examinations.

Candidates should regularly practice numerical questions from:

Subnetting

• Number of hosts

• Number of subnets

CRC

• Dataword

• Divisor

• Remainder

• Codeword generation

Hamming Distance

• Error Detection:

• Minimum Distance = s + 1

• Error Correction:

• Minimum Distance = 2s + 1

RSA Algorithm

• n = p × q

• φ(n) = (p − 1)(q − 1)

Preparation Tips for UGC NET Computer Science Unit 9

Preparing for Unit 9 requires a combination of conceptual understanding and regular revision. Candidates should focus on frequently asked topics and practice previous year questions to improve accuracy and familiarity with the exam pattern.

• Solve previous year questions regularly.

• Memorise OSI layer keywords.

• Learn header structures thoroughly.

• Practice numerical problems daily.

• Revise TCP vs UDP differences.

• Focus on repeated concepts rather than isolated facts.

• Make short revision notes for formulas and keywords.