SCI 2022 Paper Solution

[ Option A ]

Von Neumann architecture is one of the primary foundational computer architectures that describes the basic structure of computer systems with a shared memory for instructions and data.
The Microarchitecture refers to how the architectural instructions are implemented in hardware, detailing the processor’s internal structure.

[ Option D ]

[ Option C ]

[ Option D ]

The MacOS (formerly OS X) uses the XNU kernel, which is a hybrid kernel. This kernel architecture combines features from both the microkernel and monolithic kernel designs.

[ Option C ]

Spatial Locality is a principle of memory access that states if a memory location is accessed, nearby memory locations are likely to be accessed soon. Since arrays store data in contiguous memory locations, accessing elements sequentially benefits heavily from spatial locality. Thus, arrays highly utilize this concept.

[ Option B ]

The CSS transition property allows you to add smooth effects when changing from one style to another without using flash animations or JavaScript. Transitions enhance user experience by providing visually appealing animations with minimal effort and without complex scripting.

It provides control over the duration, timing function, and delay of the change, enabling smooth gradual changes, such as fading colors, resizing elements, or moving components when a user interacts with a page.

button {
  background-color: yellow;
  transition: background-color 1s ease;
}
button:hover {
  background-color: green;
}

In this example, when the user hovers over the button, the background color smoothly changes from yellow to green in 1 seconds.

[ Option C ]

Disk scheduling algorithms manage the order in which disk I/O requests are processed. Common methods are FCFS (FIFO), SSTF, SCAN, LOOK, etc. The SCAN (also called Elevator algorithm) which moves the disk arm across the disk servicing requests in one direction.
In Batch Processing, jobs are processed in the order they arrive or according to some simple sequence. A common scheduling method is FIFO (First In First Out), where the first job to arrive is the first to be processed.
Time-sharing systems use Round Robin Scheduling to give each process a fair share of CPU.
Interrupts are handled in the reverse order of occurrence, often following a LIFO (Last In First Out) scheme where the most recent interrupt is serviced first.

[ Option A ]

IA-32 (Intel Architecture, 32-bit) is a widely used computer architecture known for its support of a wide range of data types such as bytes (8 bits), words (16 bits), double words (32 bits), and quad words (64 bits).
It defines various data sizes and supports complex instruction sets for handling these different types efficiently, making it versatile across many computing applications.

[ Option B ]

WPA2 (Wi-Fi Protected Access 2) is the most widely used Wi-Fi security protocol. It was introduced in 2004 and uses AES (Advanced Encryption Standard) for strong encryption and security.

[ Option B ]

CSA stands for Computer Speed Addition. It refers to techniques used in computer arithmetic to perform addition faster, often by reducing the time required to handle carries during binary addition.
By designing circuits that can process sums and carries efficiently, computers can speed up arithmetic operations, which is critical in processors and digital systems.

[ Option C ]

In the TCP/IP model, the Transport Layer uses protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol), where UDP (User Datagram Protocol) is connectionless and lightweight. The Network (Internet) Layer is responsible for routing and error reporting, and uses protocols like ICMP (Internet Control Message Protocol).
Finally, the Application layer supports end-user services such as FTP for file transfer, HTTP for web access, and SMTP for email.

[ Option A ]

[ Option A ]

CPU Scheduling is the foundation of a Multiprogramming Operating System. In multiprogramming, several processes are kept in memory at the same time, and CPU scheduling decides which process will be given the CPU when it becomes available. This ensures efficient CPU utilization by keeping the processor busy as much as possible. CPU scheduling ensures that the CPU is never idle when there are processes ready to execute, improving throughput.

[ Option C ]

Software Quality Assurance (SQA) is a broad activity that ensures the software meets the required quality standards. It is not limited to just testing but covers the entire software development process.
Verification ensures that the software is being built correctly according to specifications and design documents ("Are we building the product right?"). It focuses on the process of development.
Validation ensures that the final product meets the user's needs and requirements ("Are we building the right product?"). It focuses on the product itself.

[ Option B ]

[ Option D ]

[ Option D ]

A constructor is a special member method in a class that automatically called when an object of that class is created. Its main purpose is to initialize the newly created object, such as setting initial values for its attributes. The name of constructor method is same as name the class and no return type (not even void).

public class Bike {
    String modelName;
    public Bike(String model) {
        modelName = model;
    }
    public void display() {
        System.out.println("Bike Model Name : " + modelName);
    }
    public static void main(String args[]) {
        Bike obj = new Bike("Rampayari");
        obj.display();
    }
}
OUTPUT
Bike Model Name : Rampayari

An exception is an unwanted or unexpected event that occurs during the execution of a program and disrupts the normal flow. It indicates that an error or unexpected condition has occurred.

• Exceptions are objects derived from the Throwable class in Java.
• They can be caught and handled using try-catch blocks to prevent program termination.

public class ExceptionExample {
    public static void main(String args[]) {
        try {
            int result = 10/0;
        } catch (ArithmeticException e) {
            System.out.println("Exception Occurred.");
            System.out.println("Error: Cannot divide by zero");
        }
    }
}

A bitmap is a type of digital image made of pixels arranged in a grid. Bitmaps are commonly stored in files with extensions like .bmp.

Type casting refers to converting a value from one data type to another. In Java, type casting can be implicit (Widening) or explicit (Narrowing).

• In implicit type casting, the conversion is done from a smaller type to a larger type, such as int → long → float → double, while in explicit type casting, the conversion is done from a larger type to a smaller type, such as double → int.

[ Option C ]

Direct Measure are the values we can observe or record directly. For example, how many people worked on a project (effort), how much money was spent (cost), or the number of lines of code written. They do not need extra calculation.

Indirect Measure are values we derive or calculate from direct measures. For example, productivity (lines of code per person-month), efficiency (output vs. input), or defect density (defects per thousand lines of code). These cannot be measured directly but are obtained through formulas or analysis of direct measures.

[ Option A ]

The standard port number for HTTP (Hypertext Transfer Protocol) is 80. Port 80 is the default port used for web servers serving unencrypted traffic over HTTP.

[ Option A ]

By default, IIS (Internet Information Services) allows users to access web content without requiring credentials. This is called Anonymous Authentication, where the server uses a built-in account to handle requests from unauthenticated users.

[ Option B ]

In modern education, technology is integrated to support, enhance, and facilitate teaching and learning. The use of technology to enhance the learning process in education is called Information and Communication Technology (ICT).
The ICT focus on a broad range of digital tools and resources such as computers, the internet, multimedia software, educational apps, and communication technologies like email and video conferencing.

[ Option A ]

Cascading termination refers to the situation where the termination of a parent process leads to the automatic termination of all its child processes. This mechanism is implemented by the operating system to avoid the creation of orphan processes, which are child processes left without a parent to manage them.

Importantly, cascading termination occurs regardless of whether the parent process terminates normally after completing its execution or abnormally due to an error or external interruption. This policy helps maintain system stability by cleaning up all associated child processes when the parent ends.

[ Option D ]

In C programming, when we deal with floating-point values (float or double), we use specific format specifiers inside printf() and scanf() function to write and read data respectively.

• The format specifier %f is used to read or print floating-point numbers in decimal (standard) format. This is the most common specifier for float type.
• The format specifier %e is used to read or print floating-point numbers in scientific notation (exponential form).
• The format specifier %g is used to read or print floating-point numbers in either decimal or scientific notation, whichever is more compact for the given value.

[ Option A ]

Vojer is an offline messaging application that allows users to communicate without an active internet connection.
The Bing, Yandex, and Lycos are primarily web search engines or internet services and do not focus on offline messaging.

[ Option C ]

[ Option D ]

Fault-Based Testing techniques are designed to evaluate how well a software system can handle errors or faults. The idea is to intentionally introduce faults and check whether the testing process can detect them.
Mutation Testing is a well-known fault-based testing technique. It involves making small modifications (called mutants) to the program’s source code intentionally, to check if the existing test cases can detect these faults.

[ Option C ]

The given program demonstrates the use of the StringBuffer class in Java, which is mutable, meaning its content can be modified after creation. Initially, a StringBuffer object S1 is created with the value "Complete". The string has characters at the following indices:

Index: 0 1 2 3 4 5 6 7  
Value: C o m p l e t e
The program then modifies the content using the setCharAt() method:
1. First modification: S1.setCharAt(1, 'i');

• Replaces the character at index 1 (originally 'o') with 'i'.
• The string now becomes "Cimplete".

2. Second modification: S1.setCharAt(7, 'd');

• Replaces the character at index 7 (originally 'e') with 'd'.
• The string now becomes "Cimpletd".

Finally, System.out.println(S1); prints the modified string Cimpletd.

public class StringBufferExample {
    public static void main(String args[]) {
        StringBuffer sb = new StringBuffer("Suraku");
        System.out.println("Original String : " + sb);
        sb.append(" Academy");
        System.out.println("After Append : " + sb);
        sb.insert(2, "YY");
        System.out.println("After Insert : " + sb);
        sb.delete(1, 3);
        System.out.println("After Delete : " + sb);
        sb.deleteCharAt(1);
        System.out.println("After Delete Char At : " + sb);
        sb.setCharAt(1, 'a');
        System.out.println("After Set Char At : " + sb);
        sb.reverse();
        System.out.println("After Reverse : " + sb);
        System.out.println("Current Capacity : " + sb.capacity());
        System.out.println("Current Length : " + sb.length());
    }
}
OUTPUT
Original String : Suraku
After Append : Suraku Academy
After Insert : SuYYraku Academy
After Delete : SYraku Academy
After Delete Char At : Sraku Academy
After Set Char At : Saaku Academy
After Reverse : ymedacA ukaaS
Current Capacity : 22
Current Length : 13

[ Option A ]

The Global Positioning System (GPS) uses Code Division Multiple Access (CDMA) technology for signal transmission and access. GPS satellites transmit on the same frequency, but each satellite uses a unique code to allow receivers to distinguish signals. This is the principle of CDMA.

[ Option B ]

[ Option C ]

To convert the hexadecimal number (1F.01B)₁₆ into its decimal equivalent, we first separate it into the integer part (1F) and the fractional part (.01B).

In integer part conversion, each digit is multiplied by 16 raised to the power of its position from right to left, starting with 0.
(1F)₁₆ = 1⋅16¹+F⋅16⁰ = 16+15 = 31
In fractional part conversion, each digit after the hexadecimal point is multiplied by 16 raised to a negative power corresponding to its position.
0⋅16⁻¹+1⋅16⁻²+B⋅16⁻³ = 0 + 0.00390625 + 0.002685546875 = 006591796875 ≈ 0.0065918
After combining integer and fractional parts, 31 + 0.0065918 = 31.0065918
 

[ Option C ]

Register renaming is a technique used in modern superscalar and pipelined processors to eliminate a specific type of data hazard called WAR (Write-After-Read) and WAW (Write-After-Write) hazards. These are also known as "Name Dependencies" because they arise not from a true data dependency, but from the reuse of a limited number of architectural registers.

• WAR Hazard: A later instruction tries to read an old value from a register that a previous instruction is about to overwrite.
• WAW Hazard: A later instruction tries to write to a register before an earlier instruction that also writes to the same register has completed.

[ Option D ]

[ Option D ]

Java does not support multiple inheritance with classes, i.e., a class cannot extend more than one class. However, Java allows a class to implement multiple interfaces. This provides a way to achieve multiple inheritance in Java.

When a class implements an interface, it must provide concrete definitions of all abstract methods defined in the interface. If the class does not implement all methods, it must be declared as abstract.

A class can implement multiple interfaces by separating them with a comma in the implements clause.

class Demo implements MyInterfaceP, MyInterfaceQ {
    // Implementation of methods from both interfaces
}

interface MyInterfaceP {
    void methodOne();
}
interface MyInterfaceQ {
    void methodTwo();
}
class MyClass implements MyInterfaceP, MyInterfaceQ {
    public void methodOne() {
        System.out.println("Method One from MyInterfaceP implemented.");
    }
    public void methodTwo() {
        System.out.println("Method Two from MyInterfaceQ implemented.");
    }
}
public class Driver {
    public static void main(String args[]) {
        MyClass obj = new MyClass();
        obj.methodOne();
        obj.methodTwo();
    }
}

[ Option C ]

The Software Requirements Specification (SRS) document is also known as the black box specification. It describes the what of the system, i.e., the functionality and requirements without detailing the internal workings or implementation (hence, "black box").

[ Option D ]

Physical Layer of the OSI model deals with the transmission of raw bitstreams over a physical medium. Network devices operating at the physical layer are responsible for transmitting and regenerating signals without interpreting the data.
Repeaters regenerate and amplify signals to extend the range of a network without any processing of the data.
Hubs serve as basic central connection points in Ethernet networks, forwarding signals to all ports and operating purely at the physical layer.

[ Option C ]

In a chained hash table (external hashing), each slot in the hash table holds a linked list of all elements that hash to the same index. This makes deletion easier because elements can be removed from the linked list without affecting other entries in the main hash table array.
Unlike in open addressing, stores all elements directly in the array itself, which makes deletion more complex.
Another advantage of external hashing is it handles collisions efficiently, multiple elements can exist at the same slot without affecting other slots.

[ Option D ]

The correct and standard sequence of HTML tags to start a web page is:

• <html> - The root element that wraps the entire HTML document.
• <head> - Contains meta-information about the document like the title, scripts, and styles.
• <title> - Specifies the title of the web page shown in the browser tab.
• <body> - Contains the visible content that is displayed on the web page.

This sequence ensures proper structure and rendering of the web page in browsers.

<html>
  <head>
    <title>Page Title</title>
  </head>
  <body>
    <!-- Displayable Content -->
  </body>
</html>

[ Option D ]

Reverse Polish Notation (RPN), also known as Postfix Notation, is a way of writing arithmetic expressions where the operator placed after the operands. For example, the infix expression A+B is written as AB+in RPN.

Besides RPN, there are two other common notations, Infix Notation and Prefix (Polish) Notation. In infix notation, operators are placed between operands like A+B and prefix notation (Polish Notation), operators precede the operands like +AB. In Polish Notation and Reverse Polish Notation (RPN), there is no need of parentheses.

[ Option C ]

Binary Coded Decimal (BCD) is a method of representing each decimal digit (0 to 9) using a fixed number of binary bits. Each decimal digit is encoded using 4 bits, which is exactly half a byte and commonly called a nibble.

[ Option C ]

The hexadecimal number system is a base-16 positional numeral system used widely in computing and digital electronics. It uses 16 distinct symbols to represent values from 0 to 15:

• The first 10 symbols are the decimal digits 0 to 9.
• The next 6 symbols are the letters A to F, where value of A is 10 and F is 15.

[ Option B ]

Polymorphism in C++ means "one name, many forms", where the same function or operator can behave differently depending on the context (data types or implementations). C++ primarily supports two main types of polymorphism:

Compile-Time Polymorphism: Also called static or early binding, this is resolved during compilation and includes function overloading (same function name with different parameter lists) and operator overloading (redefining operators for user-defined data types).

class Demo
{
    public:
        void show(int a) { cout <<"Value: " << a; }
        void show(double b) { cout <<"Value: " << b; }
};

Run-Time Polymorphism: Also called dynamic or late binding, this is resolved during program execution and is achieved through inheritance and the use of virtual functions (function overriding).

class Base
{
    public:
        virtual void display() { cout <<"Base Class Version."; }
};
class Derived : public Base
{
    public:
        void display() { cout << "Derived Class Version."; }
};

[ Option A ]

An IPv4 address is a 32-bit number used to uniquely identify a device on a network. It is usually represented in dotted decimal notation as four decimal numbers separated by dots, e.g., 192.248.0.1, where each number represents 8 bits.

[ Option D ]

Fabrication refers to creating fake messages or data, so authentication mechanisms are used to detect and prevent this.
Modification means altering messages during transmission. Ensuring message integrity detects such tampering.
Interception refers to unauthorized access or eavesdropping. Confidentiality (encryption) protects the message content.

[ Option D ]

The document that contains the user system requirements is the SRS (Software Requirements Specification) document. The SRS document details the functional and non-functional requirements of the system from the user's perspective. It serves as a contract between the client and the developers, outlining what the software should do and how it should perform.
DDD (Detailed Design Document), contains detailed design of modules, algorithms, and data structures.
SDD (Software Design Document), Provides high-level and low-level design details.

[ Option C ]

Referential integrity constraint ensures that a Foreign Key in one relation (R2) must always refer to an existing Primary Key in another relation (R1).
If we insert a tuple in R2 with a foreign key value that does not exist as a primary key in R1, it violates referential integrity.
If a tuple in R1 is deleted but there are still tuples in R2 that reference it, the relationship becomes invalid, causing a referential integrity violation.

[ Option C ]

The first statement is incorrect because the simple reflex agents act only on the current percept using condition-action rules. They do not consider past history.
The second statement is correct because in a deterministic environment, the next state is completely determined by the current state and action.
The third statement is correct because in AI terminology, a semi-dynamic environment means the environment state is static, but the agent’s performance score can change, reflecting the passage of time or other external evaluation factors.

[ Option A ]

[ Option C ]

A Circular Queue is also commonly known as a Ring Buffer. It is a data structure that connects the last position back to the first, forming a circle, which allows efficient reuse of buffer space.

Same as queue the circular queue data structure follows the FIFO (First In, First Out) principle and is widely used in scenarios where fixed size buffer management is needed.
The circular queue is empty (underflow) when front == -1 and full (overflow) when (rear + 1) % capacity == front.

[ Option B ]

[ Option D ]

When a process is in the Blocked State, it is waiting for some I/O service or resource to become available. Once the I/O operation or the required event is completed, the process cannot immediately start executing because the CPU may currently be busy with other processes. Therefore, it transitions to the Ready State.

[ Option A ]

Secure Hash Algorithm-1 (SHA-1) produces a message digest of 160 bits (20 bytes). SHA-1 takes an input of any length (less than 264 bits) and outputs a fixed-length hash value of 160 bits. This hash value, called the message digest, is used for data integrity verification, digital signatures, and other cryptographic applications.

[ Option C ]

Artificial Intelligence (AI) is the branch of computer science that deals with creating systems capable of performing tasks that typically require human intelligence, such as reasoning, learning, and problem-solving.

John McCarthy, an American computer scientist, is recognized as the “Father of Artificial Intelligence” because he both coined the term "Artificial Intelligence" in 1955 and organized the Dartmouth Conference in 1956, which is widely considered the birth of AI as an academic field.

• John McCarthy also created the LISP programming language, which became fundamental to early AI research.

[ Option A ]

Ethernet networks use MAC (Media Access Control) addresses as their physical addresses, which are permanently imprinted on the Network Interface Card (NIC) by the manufacturer. A MAC address is 48 bits long, equivalent to 6 bytes, and is usually represented in hexadecimal notation. 
This unique identifier ensures that devices within the same local network can correctly recognize and communicate with each other.

[ Option B ]

[ Option C ]

[ Option C ]

A Useless Channel is a communication channel where there is no correlation between input and output symbols. This means the output is completely independent of the input, the received symbol gives no information about what was sent. In this, the channel capacity is zero because the output does not carry any meaningful information about the input.
A noiseless channel, output is exactly the same as input, so there is a perfect correlation between input and output.
A lossless channel, input can be uniquely determined from the output, so correlation still exists.
A deterministic channel, each input symbol corresponds to exactly one output symbol, hence strong correlation.

[ Option B ]

Software design plays a crucial role in ensuring the Quality of software systems. A good design makes software more understandable, maintainable, reliable, and reusable. It reduces development time and effort by providing a clear blueprint before coding begins.

Software design is the foundation of software quality. It influences not only the immediate development but also the long-term success of the system by affecting maintainability, usability, performance, reliability, scalability, and reusability.

[ Option C ]

ARP (Address Resolution Protocol) is a network protocol used to map an IP Address (Logical Address) to a physical MAC Address (Physical Address) in a network.
For example, when a computer wants to send data to another device on the same network, it first uses ARP to find out the MAC address corresponding to the known IP address. This ensures that the data packets are delivered to the correct device.

[ Option B ]

In XSLT, the match attribute of the <xsl:template> element uses an XPath expression to specify which XML elements the template applies to.

<xsl:template match="XPath">
  <!-- Template content -->
</xsl:template>

To match a specific child element (like NAME) of a parent element (like PLANET), the syntax is "PARENT/CHILD", i.e., "PLANET/NAME".

<xsl:template match="PLANET/NAME">

[ Option D ]

Operating systems handle a variety of errors that may arise during process execution or hardware interaction.
Lack of paper in printer, the OS detects and handles this by notifying the user or pausing the printing process until paper is available.
Connection failure in the network, the OS manages network errors by detecting connection failures, reporting issues, and attempting reconnections or switching to backup networks.
Power failure, the OS can handle power failures by initiating safe shutdown procedures, saving unsaved data, and preserving system integrity through battery backups or power management features.

[ Option D ]

SRTF (Shortest Remaining Time First) is a Preemptive Scheduling algorithm where the process with the shortest remaining execution time is given the CPU. A long-running process might never get to execute if there is a continuous stream of new, short-burst processes arriving in the ready queue. The long-running process would always have a longer remaining time and would be repeatedly preempted, leading to starvation.

Preemptive scheduling may cause starvation, this is a general statement that is true. Starvation is a common problem in any Preemptive Scheduling algorithm that uses a priority or time-based approach, like SRTF or a Priority-Based Scheduler where low-priority processes might never get to run if there is a constant flow of high-priority processes.

Round Robin (RR) scheduling allocates CPU time in small time slices (quantum) to each process fairly, leading to better responsiveness compared to FCFS (First-Come, First-Serve), where a process waits (even short-burst ones) until the previous one completes because its Non-Preemptive Scheduling algorithm.

[ Option C ]

GSM (Global System for Mobile Communications) was developed by ETSI (European Telecommunications Standards Institute) in the late 1980s. It originated in Europe to standardize mobile communication systems.

[ Option B ]

DDoS stands for Distributed Denial-of-Service. It is a type of cyberattack where multiple compromised systems flood the bandwidth or resources of a targeted system, usually one or more web servers.
The goal of a DDoS attack is to make the targeted online service or resource unavailable to legitimate users by overwhelming it with a massive volume of traffic or requests. This attack originates from multiple sources, making it more difficult to defend against than a single-source DoS attack.

[ Option D ]

The statement (I) is true, CDMA spreads the signal over the entire available spectrum using spread-spectrum technology.
The statement (II) is true, every user has a unique pseudo-random code, which allows multiple users to share the same frequency simultaneously.
The statement (III) is false, CDMA technology offers more security compared to GSM because it uses spread spectrum technology and encryption, making signal interception and detection harder. 
The statement (IV) is false, A SIM card is not always required for CDMA devices. CDMA phones traditionally do not rely on SIM cards, unlike GSM phones.

[ Option A ]

Protocols such as SMTP (Simple Mail Transfer Protocol), HTTP (Hypertext Transfer Protocol), and FTP (File Transfer Protocol) operate at the Application Layer of the OSI and TCP/IP models. The application layer provides network services directly to end-user applications and manages communication between users and networks.
SMTP is responsible for email transmission, HTTP is used for accessing and transferring web pages, and FTP allows file transfers between systems.

[ Option D ]

A queue data structure has several important applications in the real world. It is commonly used when a resource is shared among multiple consumers, as it manages access by processing requests in a First-In-First-Out (FIFO) manner. This ensures fairness by servicing requests in the order they arrive.
Queues are also used when data is transferred asynchronously between two processes, acting as a buffer to hold data until the receiving process is ready, as seen in the producer-consumer problem with message queues.
Another significant use of queues is in load balancing, where tasks or workloads are distributed evenly across multiple servers or systems by holding tasks in a queue until resources are available to process them.
Overall, queues play a vital role in managing resource sharing, buffering asynchronous data transfer, and balancing workload efficiently in computing systems.

[ Option C ]

The Creeper virus, created in 1970s by Bob Thomas at BBN Technologies, is considered the first computer virus. It was an experimental self-replicating program that moved across ARPANET and displayed the message: "I'M THE CREEPER, CATCH ME IF YOU CAN!".

[ Option C ]

Symmetric key algorithms use the same key for encryption and decryption. RC4, Blowfish, and DES (Data Encryption Standard) are examples of symmetric key cryptography algorithms.
Diffie-Hellman is a key exchange algorithm and is part of asymmetric key cryptography, used to securely exchange cryptographic keys over a public channel. It is not an encryption algorithm itself.

[ Option A ]

Orphan Process:
In operating systems, when a parent process terminates before its child process completes, the child process is still running. Such a child process is called an orphan. Typically, the orphan process is adopted by the init process, ensuring proper cleanup when it finishes.
Zombie Process:
A zombie process is a process that has finished execution but still appears in the process table because its parent process has not yet collected its exit status via the wait() system call. Zombie processes do not consume CPU resources but occupy a slot in the process table until the parent collects the exit information.

[ Option A ]

A register in digital electronics is a group of flip-flops used together to store multiple bits of data. Each flip-flop typically stores one bit, so a register consisting of multiple flip-flops can hold multi-bit binary data. Registers are used for temporary data storage.

[ Option D ]

In ADO.NET, the DataTable object represents an in-memory table of data. One of its powerful features is that it exposes events which allow you to monitor and respond to changes in its data. The main events include:

[ Option D ]

A Proxy Firewall filter works at the Application Layer of the OSI model. It acts as an intermediary between a client and a server, intercepting all requests and responses.

[ Option D ]

Machine Learning (ML) is a subfield of Artificial Intelligence (AI) that focuses on developing algorithms and systems which can learn from data and improve their performance automatically without explicit programming.

• Machine learning algorithms improve their performance by using learned patterns and adjusting themselves based on feedback or additional data.
• They are designed to execute specific tasks, such as image recognition, translation, or prediction, with increasing accuracy.
• The key feature is that their performance improves over time with experience, meaning the more data or iterations they receive, the better they typically become at solving the given task.

[ Option C ]

Object-Oriented Programming (OOP) is built on PIE principles, Polymorphism, Inheritance and Encapsulation. Among these, inheritance is the key feature that significantly boosts code reusability.

Inheritance allows a new class (subclass or derived or child class) to acquire the properties and behavior (data and methods) of an existing class (superclass or base or parent class). This means that the subclass reuses the code already written in the parent class without needing to rewrite it.

• This code reusability minimizes redundancy, enhances programming efficiency, and makes maintenance easier by keeping common code centralized within the base class.

[ Option C ]

Expression: ( A + B ) * ( C * D - E ) * F / G

[ Option C ]

When a process fails, most operating systems record the error information in a log file. This log file serves as a permanent record to help system administrators, developers, and support personnel diagnose and troubleshoot problems.

By recording details such as the time of failure, type of error, and sometimes even a memory dump, log files help developers and administrators trace the cause of the failure. This approach provides a reliable and centralized way to analyze problems and ensure system stability.

[ Option C ]

To solve this base arithmetic problem, we first understand that numbers in different bases can be converted to decimal (base 10) to simplify calculations. By converting each term to decimal, we can form an algebraic equation in terms of the unknown base x and then solve for it using standard algebraic methods.

Alternatively, since the bases involved are small integers, a trial-and-error method can be used to test reasonable values of x until the sum matches the decimal equivalent of the right-hand side.

Method 1: Algebraic / Decimal Conversion Method:
Convert each number to decimal:

• (146)_x = 1⋅x²+4⋅x+6 = x² + 4x + 6
• (313)_x−2 = 3⋅(x−2)²+1⋅(x−2)+3 = 3x² − 11x + 13
• (246)₈=2⋅8² + 4⋅8 + 6 = 166

Form the equation in decimal:

(x² + 4x + 6) + (3x² − 11x + 13) = 166
4x² − 7x + 19 = 166
4x² − 7x − 147 = 0
When solving this quadratic equation, we found value of x is 7.
Method 2: Trial-and-Error
Understand the Base Involved:

• The base x must be greater than or equal to 7 because the digit '6' appears in (146)_x, so x>6.
• x−2 must be greater than or equal to 4 since the digit '3' appears in (313)_x−2. Hence, x−2>3 : x>5.

Check possible integer values for x:
From the given option 5,6,7,9, try only x=7,9 (because x must be >6), by converting each term to decimal and verify if the sum equals the decimal value of (246)₈ (which is 166).
 

[ Option B ]

[ Option A ]

An entity in a database or data modeling context is a real-world object or concept that can be uniquely identified and about which data can be stored.
Entities are represented by a set of attributes, which describe the characteristics or properties of that entity. For example, a Student entity may have attributes like Rollno, Name, Class, Age, and Address. These attributes provide information about the entity and are used to uniquely distinguish one entity instance from another.

[ Option B ]

In Object-Oriented Programming System (OOPS), a constructor is a special member function that automatically gets called when an object of a class is created. Its main purpose is to initialize newly created objects. There are several types of constructors, each serving a distinct purpose in object initialization.

Default Constructor: This is a constructor that takes no arguments and initializes objects with default values.

class Demo {
    int x;
public:
    Demo() { x = 0; } // Default Constructor.
};

Parameterized Constructor: It takes one or more parameters, allowing the object’s data members to be initialized with user-defined values at the time of object creation.

class Demo {
    int x;
public:
    Demo(int a) { x = a; } // Parameterized Constructor.
};

Copy Constructor: The constructor which takes object as an argument of its own types, called copy constructor. It creates a new object as a copy of an existing object.

class Demo {
    int x;
public:
    Demo(int a) { x = a; } // Parameterized Constructor.
    Demo(Demo &obj) { x = obj.x; } // Copy Constructor.
};

There is no such thing as a 'friend constructor' in mainstream object-oriented programming languages like C++, Java. We can have friend functions or friend classes in C++, but constructors cannot be declared as friend.

[ Option B ]

A queue is a linear data structure that follows the FIFO (First In, First Out) principle. This means the first added element to the queue will be the first one to be removed. There are mainly two operations enqueue (adding an element at the rear end) and dequeue (removing an element from the front end).

[ Option D ]

The 0/1 Knapsack problem is a classic combinatorial optimization problem where each item must be either included or excluded from the knapsack. In this version, the objective is to minimize the profit (or cost), rather than maximize it. Simple greedy methods are not suitable here because they do not always guarantee an optimal solution for 0/1 decisions.

To handle minimization effectively, the Branch & Bound (0/1) technique is used. This method systematically explores all possible combinations of items while using bounds to prune suboptimal branches, which reduces unnecessary computations. While dynamic programming or backtracking can also solve the problem.

[ Option D ]

Vint Cerf, along with Robert Kahn, is regarded as the “Father of the Internet.” He played a key role in designing the TCP/IP protocols, which are the foundation of modern internet communication.
Mark Zuckerberg co-founded Facebook in 2004 while studying at Harvard University. He later became the CEO of Facebook (Meta).
Larry Page, along with Sergey Brin, co-founders of Google, the search engine and technology company.

[ Option B ]

To compute the 8’s complement of a number, we use the (r−1)’s complement method, where r is the base. First, we find the (r−1)’s complement by subtracting each digit of the number from (r−1), and then we add 1 to the result to get the r’s complement.

For example, consider the octal number (7650)₈. Here, the base r=8, so r−1=7. To find the 7’s complement of 7650, we subtract each digit from 7 individually.

• 7 : 7 - 7 = 0
• 6 : 7 - 6 = 1
• 5 : 7 - 5 = 2
• 0 : 7 - 0 = 7

Thus, the 7’s complement of (7650)₈ is 0127. Next, to obtain the 8’s complement, we add 1 to the 7’s complement, 0127+1= 0130.

Note: The addition is performed according to the base. Here, since it is base 8 (octal), each digit is added modulo 8, and any carry is handled within octal arithmetic.

[ Option A ]

In the Software Development Life Cycle (SDLC), the actual programming or coding of the software is done during the development phase, which is often referred to as the "development and documentation" phase.

This phase follows the design and analysis phases and involves writing the source code based on detailed design specifications.

[ Option B ]

Single Parity Check, Checksum, and Cyclic Redundancy Check (CRC) are primarily error detection methods. They detect if an error has occurred in the transmitted data but do not necessarily correct the errors.
Hamming Distance refers to Hamming Code, which is a method used for both error detection and error correction. It can detect and correct single-bit errors by adding redundant bits to the data.

[ Option C ]

In HTML, a hyperlink is created using the <a> (anchor) tag. The href attribute specifies the URL of the page the link goes to. The text between the opening <a> and closing </a> tags is the clickable part that the user sees.

<a href="https://www.surakuacademy.com">Suraku Academy</a>

[ Option B ]

[ Option B ]

[ Option A ]

Quantizing noise occurs during the quantization process in Pulse Code Modulation (PCM). PCM converts an analog signal into a digital signal by sampling the amplitude of the analog signal at regular intervals and then quantizing these samples to the nearest value among a finite set of levels. The difference between the actual analog value and the quantized digital value is called quantization error or quantizing noise.

• PCM (Pulse Code Modulation): Quantization is a necessary step, hence quantizing noise appears.
• TDM (Time Division Multiplexing): No quantization; it only multiplexes signals in the time domain.
• FDM (Frequency Division Multiplexing): Signals are separated by frequency bands, no quantization noise.
• PPM (Pulse Position Modulation): The noise mainly comes from timing errors, not quantization.

[ Option C ]

A stack is a linear data structure that follows the LIFO (Last In, First Out) principle, where elements are added or removed only from one end called TOP of the stack. 
The process of adding or inserting new element at the top of stack is called Push Operation. The process of deleting or removing an existing element from top of stack is called Pop Operation.