UGC NET Paper 2 Computer Science Mock Test - 5 - UGC NET MCQ

Network layer congestion policy are:

1)Virtual circuits vs datagram inside the subnet

2)Packet sequencing and service policy

3)Packet discard policy

4)Routing algorithm

5)Packet lifetime management

• The process of dividing an analog signal into a string of discrete outputs, each of constant amplitude, is called Quantization.
• The process of enhancing an analog signal is called Amplification.
• Irregular behaviour or jerk or loss of continuity in analog signal is called Strobing.
• Conditioning is a process of manipulating an analog signal in a way that prepares it for the next stage of processing.

So, option (D) is correct.

Dijkstra’s algorithm  

Link state protocols, sometimes called shortest path first or distributed database protocols, are built around a well-known algorithm from graph theory, E. W. Dijkstra's shortest path algorithm, which is  is a graph search algorithm that solves the single-source shortest path problem for a graph with non-negative edge path costs, producing a shortest path tree. This algorithm is often used in routing and as a subroutine in other graph algorithms.

Data Scrubling ( Data Cleaning.):-The process of removing data in a database that is incorrect, incomplete, improperly formatted, or duplicated before sending it into data warehouse.

Subnormal fuzzy set: A fuzzy set wherein no membership function has its value equal to 1.

Convex fuzzy set: It is a fuzzy set which has a membership function whose membership values are strictly monotonically increasing or strictly monotonically decreasing or strictly monotonically increasing than strictly monotonically decreasing with increasing values for elements in the universe

Nonconvex fuzzy set: The membership values of the membership function are nor strictly monotonically increasing or decreasing or strictly monotonically increasing than decreasing.

The correct answer is (i) - True, (ii) - True

Key Points

• (i) Relative URLs do not require protocol identifiers.
  • A relative URL specifies only a portion of the full path needed to identify the resource within a website. Relative URLs are helpful in situations where you need to navigate within the same site as they don't require you to include the full website address.
  • For example, if you have a webpage at http://www.example.com/pets/dogs.html, a relative URL to refer to a new page called cats.html in the same directory would just be "cats.html".
• (ii) The syntax "Scheme://Server/Path/Resource" is indeed the correct format of an absolute URL.
  • "Scheme" refers to the protocol to be used, like http, https, ftp, etc.
  • "Server" refers to the domain name (like www.wikipedia.org).
  • "Path" specifies the resource location.
  • And, "Resource" is the specific file or page being referred to.
  • For example, in the URL "http://www.example.com/pets/dogs.html", "http" is the scheme, "www.example.com" is the server, "/pets/" is the path, and "dogs.html" is the resource.

The correct answer is option 2.

Concept:

IEEE single-precision floating-point:

IEEE single-precision floating-point computer numbering format is a binary computing format that takes up 4 bytes (32 bits) of memory. Binary32 is the official name for the 32-bit base 2 formats in IEEE 754-2008. IEEE 754-1985 referred to it as single.

IEEE single-precision format:

Explanation:

The given data,

Decimal value =(-1)^s x 1.M x 2^{Base Exponent -Bias}

Bias value in IEEE single-precision format is 127

R_A = 1100 0001 0100 0000 0000 0000 0000 0000

RA sign= 1

RA Base Exponent =100 0001 0 = 130

R_A Mantisa = 100 0000 0000 0000 0000 0000 = 1.100 0000 0000.....

Decimal value = (-1)¹ x1.1 x2^130-127 =-1.1x2³= -1100 = (-12)₁₀

A=-12

RB = 0100 0010 0001 0000 0000 0000 0000 0000

RA sign= 0

RA Base Exponent =100 0010 0= 132

RA Mantisa = 001 0000 0000 0000 0000 0000 = 1.001 000000.....

Decimal value = (-1)0 x1.001 x2132-127 =+1.001x25= + 100100 = (+36)10

B=+36

RC = 0100 0001 0100 0000 0000 0000 0000 0000

RA sign= 0

RA Base Exponent =100 0001 0= 130

RA Mantisa =100 0000 0000 0000 0000 0000= 1.100 0000.....

Decimal value = (-1)0 x1.1 x2130-127 =+1.1x23= + 1100 = (+12)10

C=+12

Option 1: A + C = 0

True, A+C= -12+12=0

Hence it is true.

Option 2: C = A + B

False, A+B= -12+36=+24

it not equal to C. Hence it is false.

Option 3: B = 3C

True, B=3C

=3x+12 =36 =B

it equal to B. Hence it is true.

Option 4: (B - C) > 0

True, (B-C) >0

=(36-12)=24>0

Hence it is true.

Hence the correct answer is C = A + B.

Fuzzy logic machines are used in washing machines at assesses the various parameters of washing load and continuously adjusts the settings of spinning. Various system assesses and adjust some of parameters like:

i) The weight of the load

ii) Type of the fabric

iii) The amount and temperature of the water

iv) The amount of detergent

v) The dirt in the water or rinse needs

Output of MUX 1:

X = C̅.A + C.B

Output of MUX 2:

Concept:

Phases of the compiler are:

Diagram

The Correct Answer is option 4.

The correct answer is option 2.

Concept:

Statement 1: WiFi uses radio waves to create wireless connections, WiMax uses spectrum to deliver the connection.

​The given statement is true.

• Wifi is an abbreviation for Wireless Fidelity. WiFi creates wireless high-speed internet and network connections by utilizing radio waves. To build hotspots, a wireless adaptor is required.
• WiMax is an abbreviation for Wireless Interoperability for Microwave Access. WiMax uses spectrum to deliver the connection to the network and handle a larger inter-operable network.​

Statement 2: WiFi is defined under IEEE 802.11x standards, while WiMax is defined under IEEE 803.16y standards.

​The given statement is true.

• Wifi is specified by IEEE 802.11x standards, where x denotes different WiFi versions.
• WiMax is specified by IEEE 802.16y standards, where y denotes different WiMax versions.

Statement 3: WiMax covers a comparatively larger area than WiFi.

​The given statement is true.

• The WiFi network has a maximum range of 100 meters.
• The WiMax network has a maximum range of 90 kilometers.

Hence the correct answer is (I), (II), and (III).

Note:

As per the official answer key, statement two is incorrect, but as per the IEEE standards statement, two is also correct. All three statements are correct hence the correct answer is option 2 i.e (I), (II), and (III).

White-box testing, sometimes called glass-box testing, is a test case design method that uses the control structure of the procedural design to derive test cases.

Using white-box testing methods, the software engineer can derive test cases that

(1) guarantee that all independent paths within a module have been exercised at least once

(2) exercise all logical decisions on their true and false sides

(3) execute all loops at their boundaries and within their operational bounds

The correct answer is Both I and II.

Key Points

• Packet filtering firewalls:
  • As the most “basic” and oldest type of firewall architecture, packet-filtering firewalls create a checkpoint at a traffic router or switch.
  • These work at the Network layer of the OSI networking model.
  • The firewall performs a simple check of the data packets coming through the router inspecting information such as the destination and origination IP address, packet type, port number, and other surface-level information without opening up the packet to inspect its contents.
  • Packet filter firewall operates at the network and transport layer. Hence, Statement 2 is correct.
• A proxy firewall:
  • It is a network security system that protects network resources by filtering messages at the application layer. Hence, Statement 1 is correct.
  • A proxy firewall is also be called an application firewall or gateway firewall.
  • A proxy firewall is also a proxy server, but not all proxy servers are proxy firewalls.

Data:

number of bits = n = 8

Formula:

Range of 2's compliment number with n bits is (–2^n-1 ) to +(2^n-1 – 1)

Smallest integer = –2n-1

largest integer = 2n-1 – 1

Calculation:

Smallest integer = –28-1 = –128

The correct answer is option 4.

Concept:

Binary search tree:

A binary search tree (BST) is a binary tree in which each node has a Comparable key (and an associated value) that is greater than the keys in all nodes in that node's left subtree and less than the keys in all nodes in that node's right subtree.

Deletion of nodes in binary search tree:

A node to be deleted

1. No children then simply delete it.
2. Only one child then connects to the child subtree to its grandparent.
3. Both children(subtrees) then:
   1. Replace with its INORDER SUCCESSOR (Minimum node of the right subtree). or
   2. Replace with its INORDER PREDECESSOR (Maximum node of the left subtree).

Explanation:

The given BST, A node to be deleted has a root node i.e 50.

From deletion algorithm of rule 3.1 or 3.2 applicable for the given condition.

Replace with its INORDER SUCCESSOR:

Here is the minimum node of the right subtree is the node= 59

Replace with its INORDER PREDECESSOR:

Here the Maximum node of the left subtree is the node= 48.

Hence the correct answer is 48 or 59.

From the last question Schedule B is Pre-emptive priority schedule, so its Gantt chart is:

P1 wait for: 4-8 => 4

P2 wait for: 1-14 => 13

P3 wait for: 2-15 => 13

P4 wait for: 4-4 => 0

Average wait time = 30/4 = 7.5

It is clear that it is FCFS because the order of execution is the order of arrival.

The correct answer is 7.25

average waiting time = 0 + 9 + 9 + 11 / 4

average waiting time = 29/4 = 7.25

The correct answer is Select BookID from Stulibrary where Return_date is NULL;

Key PointsThis query fetches the BookID of books from the Stulibrary table where the Return_date is NULL, indicating that the books have been issued but have not yet been returned.

• SELECT BookID: This retrieves only the `BookID` column, focusing on book identification.
• FROM Stulibrary: This specifies the `Stulibrary` table as the source of data.
• WHERE Return_date is NULL: This crucial part filters the results. A `NULL` value in the `Return_date` column indicates that the book has not been returned yet.

The correct answer is BookID, Issued date

Key PointsIn the context of the Stulibrary table, the choice of primary key would typically depend on how the data is structured and the specific requirements of the application. The primary key is a unique identifier for each record in a database table. From the information given, no explicit mention of the primary key configuration is made, but we can infer the most logical option based on common practices.

• Option 1) BookID: While BookID could uniquely identify each book, it may not uniquely identify each record in the Stulibrary table if the same book can be issued multiple times (which is likely in a library scenario).
• Option 2) BookID, StuID: This combination could be considered if a book could only be issued to a student once at any time. However, the same student could potentially issue the same book multiple times at different periods, making this combination insufficient to uniquely identify each record.
• Option 3) BookID, Issued_date: This combination is more likely to uniquely identify each record in the Stulibrary table because it considers both the BookID and the Issued_date. A book can be issued to any number of students over time, but a specific BookID would not be issued to more than one student on the same date, assuming each record represents a unique issuing event.
• Option 4) Issued_date: Just the Issued_date alone would not be sufficient to uniquely identify each record because multiple books can be issued on the same date.

Given this context, Option 3) BookID, Issued_date is the most plausible choice for the primary key of the Stulibrary table, as it best fulfills the uniqueness requirement across all records, considering that the same book can be issued on different dates to either the same student or different students.

The correct answer is Select * from Stulibrary order by StulD Asc;

Key PointsAn educational institute in Delhi uses a DBMS to store student details. The database named 'school-record' has two tables:

• Student: Stores general student information
• Stulibrary: Tracks issued books

SELECT * FROM Stulibrary ORDER BY StuID ASC;
Explanation:

• SELECT *: This clause retrieves all columns (*) from the Stulibrary table.
• FROM Stulibrary: This clause specifies the table from which data will be retrieved (Stulibrary).
• ORDER BY StuID: This clause sorts the results based on the StuID column.
• ASC: This keyword specifies ascending order for sorting (StuID values from lowest to highest).

Following are the techniques used for building cross compilers

1. Canadian cross
2. GCC compiler
3. Manx Aztec C cross compiler
4. Microsoft C cross compiler

The main difference between compiler and cross compiler is that

• The compiler is a software that transforms a computer program written in high-level programming language into machine language
• The cross compiler is a type of a compiler that can create an executable code for a platform other than the one on which the compiler is running.

• Bourne Shell - If you are using a Bourne-type shell, the $ character is the default prompt.
• C Shell - If you are using a C-type shell, the % character is the default prompt.

The functions of a dispatcher mop the following:

• Context switches, in which the dispatcher saves the state (also known as context) of the process or thread that was previously running; the dispatcher then loads the initial or previously saved state of the new process.
• Switching to user mode.
• Jumping to the proper location in the user program to restart that program indicated by its new state.

A Lexeme is a sequence of alphanumeric characters in a token. The term is used in both the study of language and in the lexical analysis of computer program compilation. In the context of computer programming, lexemes are part of the input stream from which tokens are identified.

The parity bit ensures that the total number of 1-bits in the string is even or odd. Accordingly, there are two variants of parity bits: even parity bit and odd parity bit. If that count is odd, the parity bit value is set to 1, making the total count of occurrences of 1s in the whole set (including the parity bit) an even number. In the case of odd parity, the coding is reversed. For a given set of bits, if the count of bits with a value of 1 is even, the parity bit value is set to 1 making the total count of 1s in the whole set (including the parity bit) an odd number. If the count of bits with a value of 1 is odd, the count is already odd so the parity bit's value is 0.

The graph that shows the basic blocks and their successor relationship is called flow graph. A flow graph is a graph of the compiler which describes the basic blocks and how the program control is passed between the blocks. Basic block is a set of statements that always executes in a sequence one after the other. A flow graph is a directed graph with flow control information added to the basic blocks.

In software testing, Gorilla testing is required to check the functionality of a particular module at a time. In other words, we can say that gorilla testing is important where a module of the system is frequently tested to guarantee that it is working properly.