[SOLUTION] SET D1 HISSAN CENTRAL EXAMINATION-2081 (2025)

 

HISSAN CENTRAL EXAMINATION-2081 (2025)

Grade: XII                Time: 2 Hrs                FM: 50

Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.

GROUP A

Multiple Choice Questions.

Tick / Select the best alternative.                                                                                   [9×1=9]

1. The key that identifies each record uniquely, is called
   a) Primary Key
   b) Record Key
   c) Unique Key
   d) Keyword
2. Which SQL statement is used to modify data in an existing table?
   a) CREATE
   b) ALTER
   c) UPDATE
   d) DELETE
3. Which of the following is used to display the output in PHP?
   a) echo
   b) print
   c) ? write
   d) both (a) and (b)
4. What is the correct way to write “if” statement in JavaScript?
   a) if i=7 then.
   b) if (i == 7)
   c) if i==7
   d) if i = 7
5. A function which calls itself is called a ………
   a) Self-Function
   b) Auto Function
   c) Recursive Function
   d) Static Function
6. Which device provides path for the packets for data transmission?
   a) Hub
   b) Router
   c) Switch
   d) Repeater
7. PaaS stands for…..
   a) Public as a service
   b) Platform as a Service
   c) Protocol of a Service
   d) Policy as a Service

8. Which feature of OOP indicates code reusability?
   a) Abstraction
   b) Polymorphism
   c) Encapsulation
   d) Inheritance
9. Which SDLC model is best suited for projects where requirements change frequently?
   a) Waterfall model
   b) Spiral model
   c) Agile model
   d) V-shaped model

 

GROUP B

Short Answer Questions                                                [5×5=25]                                                                                                    

10. What is Database? Explain centralized and distributed database. [2+3]

Ans:

Databases can be categorized based on their storage and management into Centralized Databases and Distributed Databases.

1. Centralized Database

A centralized database is a database system where all the data is stored and managed in a single location, typically on a single server or mainframe. Users from different locations access this database through a network.

Characteristics of Centralized Database:

a)       Stored in a single location.

b)      Managed and controlled by a central database management system (DBMS).

c)       Users access data through client applications over a network.

Example of Centralized Database:

a)       Banking systems (core banking databases)

b)      University student record systems

c)       Government databases 

2. Distributed Database

A distributed database is a database system where data is stored across multiple locations (servers or sites), connected through a network. Each site maintains its own database and communicates with others.

Types of Distributed Databases:

1)      Homogeneous Distributed Database: All sites use the same DBMS and structure.

2)      Heterogeneous Distributed Database: Different sites may have different DBMSs and structures.

Characteristics of Distributed Database:

a)       Data is spread across multiple locations.

b)      Can be replicated or fragmented across different sites.

c)       Sites communicate via a network.

Example of Distributed Database:

a)       Cloud storage services (Google Drive, Amazon S3)

b)      Online e-commerce platforms (Amazon, eBay)

c)       Social media platforms (Facebook, Instagram)

OR
Explain any two types of database model.      [5]

Ans:

A database model is a logical design and structure that defines how data is stored, organized, and manipulated in a database. Any two types of database model are explained below:

Hierarchical Database Model:

Hierarchical database model is one of the old and simplest database models in which records are logically organized in the form of an inverted tree. It starts with the root node (parent) at the top and the branch (child) formed below.

Ø                         In this model, each record (node) has a single parent, but it can have multiple children, creating                a hierarchy of data and one-to-one and one-to-many parent-child relationships.

Ø                         Example: A diagram representing a network database model is as follows:  Draw from Note

Network Database Model:

The network database model is a modified version of the hierarchical database model in which records are logically organized in the form of a graph-like structure, where one record can have multiple parents and also multiple children, creating a network of data.

Ø                         It supports one-to-one, one-to-many, and many-to-many relationships.

Ø                         Example: A diagram representing a network database model is as follows:   Draw from Note

11. Write JavaScript code to find the factorial value of a number.    [5]

Ans:

<!DOCTYPE html>

<html>

<head>

    <title>Factorial of a Number</title>

</head>

<body>

    <script>

        function calculateFactorial() 

        {

            var n, fact = 1;

            n = parseInt(prompt("Enter a number:"));

            if (isNaN(n) || n < 0) 

            {

                document.write("Invalid input! Please enter a non-negative integer.");

                return;

            }

            for (var i = 1; i <= n; i++) {

                fact = fact * i;

            }

            document.write("The factorial of " + n + " is: " + fact);

        }

        calculateFactorial();

    </script>

</body>

</html>

Example Output:

Enter a number: 5

The factorial of 5 is: 120

OR
Differentiate between Client-Side Scripting and Server-Side Scripting.      [5]

Ans:

Scripting in web development is broadly categorized into server-side and client-side scripting. Both play crucial roles in building dynamic and interactive web applications. 

1. Server-Side Scripting: Server-side scripting is executed on the web server before the page is sent to the user’s browser. It is used to handle database operations, authentication, and business logic.

2. Client-Side Scripting: Client-side scripting is executed on the user’s browser, allowing web pages to be interactive and dynamic without constant communication with the server.

Key Differences:

Feature (Aspect)	Server-Side Scripting	Client-Side Scripting
Execution	On the web server	On the user’s browser
Performance	Slower due to server processing	Faster as it runs locally
Security	More secure (hidden from users)	Less secure (visible to users)
Use Cases	Authentication, database handling, API requests	UI interactions, animations, form validation
Examples	PHP, Node.js, Python, Java	JavaScript, HTML, CSS

 

12. Why are polymorphism and inheritance important?             [5]

Ans:

Inheritance and polymorphism are two fundamental features of Object-Oriented Programming (OOP) that provide significant benefits to programmers. Here's how they help:

1. Inheritance (Code Reusability & Hierarchy):

Inheritance allows programmers to create new classes based on existing ones, reducing redundancy and improving maintainability. This provides several advantages(importances):

a) Code Reusability: Common functionalities are defined in a base class and reused in derived classes.

b) Faster Development: New classes can inherit existing logic instead of writing from scratch.

c) Scalability: Easy to extend existing code with additional features.

d) Better Organization: Establishes a clear relationship between general and specific classes.

2. Polymorphism (Flexibility & Dynamic Behaviour):

Polymorphism enables objects to take multiple forms, allowing programmers to write more flexible and scalable code. This provides several advantages(importances):

a) Method Overriding: Subclasses can modify inherited methods for specific behaviour.

b) Method Overloading: Allows multiple functions with the same name but different parameters, improving readability.

c) Dynamic Binding (Runtime Polymorphism)

d) Simplifies Code Maintenance: Reduces complexity by allowing generic function calls.

 

13. What is e-learning? Write any three advantages of e-learning.  [2 + 3]

Ans:

E-Learning refers to the use of electronic media, such as the internet, computers, and digital platforms, to deliver educational content and facilitate learning. It enables students to access courses, training, and resources remotely, without the need for traditional classroom settings.

Types of E-Learning:

1. Synchronous: Real-time classes with instructors and students interacting (e.g., live webinars).

2. Asynchronous: Pre-recorded lessons and materials that learners can access at any time (e.g., MOOCs, video tutorials).

3. Blended Learning: Combines online learning with traditional face-to-face education. 

Advantages of E-Learning:

a)       Flexibility to learn anytime, anywhere. Example: A working professional, can take online courses whenever it fits her schedule, whether day or night.

b)      Cost-effective, as it reduces the need for physical infrastructure. Example: A company saves money by offering online employee training instead of organizing physical classes with travel and room costs.

c)       Access to a wide variety of resources and expert instructors. Example: A person can take an online graphic design course with top instructors from Skillshare, using video tutorials and project files.

 

14. Explain about waterfall model of SDLC.        [5]

Ans:

The Waterfall Model is a linear and sequential approach to software development, where each phase of the development process 1 must be completed before moving on to the next 2 one. It's like a waterfall, where the water flows steadily downwards through different stages.  

Phases of the Waterfall Model:

1. Requirements Gathering and Analysis: The project's goals, scope, and requirements are defined.

2. Design: The system's architecture, components, and interfaces are designed.

3. Implementation (Coding): The software is developed based on the design.

4. Testing: The software is rigorously tested to identify and fix bugs.

5. Deployment: The software is released to the end-users.

6. Maintenance: Ongoing support and maintenance of the software.

Advantages (Pros):

a) Simple and easy to understand.

b) Provides a structured approach to development.

c) Well-suited for projects with well-defined requirements.

Disadvantages (Cons):

a) Inflexible: Difficult to accommodate changes once development begins.

b) Time-consuming: Delays in one phase can significantly impact the project timeline.

c) Limited customer involvement: Customer feedback is primarily seen at the end of the project.

 

 

GROUP C

Long Answer Questions                                                        [2×8=16]                                                                                                  

15. What is computer network? Explain simplex, half duplex and full duplex mode of communication.    [2+6]

Feature	Simplex	Half Duplex	Full Duplex
Direction of Data	One-way only.	Two-way, but not at the same time.	Two-way simultaneously.
Example	TV broadcasting.	Walkie-talkies.	Telephone calls.
Advantages	Simple and cost-effective.	Allows two-way communication.	Fast and efficient.
Disadvantages	No two-way communication.	Slower than full duplex.	Requires more complex hardware.

Ans:

Computer network is a group of two or more computers and devices connected to each other through wired or wireless media to exchange data and information and share hardware, software and other resources. Computer networks are classified as follows:

1) LAN (Local Area Network)

2) MAN (Metropolitan Area Network)

3) WAN (Wide Area Network)

Advantages of computer network are as follows:

a)       Resource Sharing

b)      Data and File Sharing

c)       Communication and Collaboration

d)      Centralized Data Storage and Management

e)      Cost Efficiency

Mode of communication refers to the way data is transmitted between devices in a network or communication system. It determines the direction and timing of data flow. There are three primary modes of communication as follows:

1) Simplex: One-way communication where one device sends and the other receives. Example: Radio broadcasting, where stations transmit to receivers without direct communication.

2) Half duplex: Two-way communication where devices can send and receive, but not simultaneously. Example: Walkie-talkies, where users can talk and listen, but not at the same time.

3) Full duplex: Two-way communication where devices can send and receive simultaneously. Example: Telephone calls, where both parties can speak and listen simultaneously.

Comparison of Simplex, Half Duplex, and Full Duplex:

 

16. Write a C program to enter roll, name, school name and district of 15 students and display the information in proper format using structure.

Ans:

#include <stdio.h>

#include <conio.h>

struct student

{

    int roll;

    char name[50];

    char school[50];

    char district[50];

};

void main()

{

        struct student s[15]; 

        int i;

        clrscr();

                     for (i = 0; i < 15; i++)

                     {

        printf("\nEnter details for student %d:\n", i + 1);

        printf("Enter Roll Number: ");

        scanf("%d", &s[i].roll);

        printf("Enter Name: ");

        scanf("%s", s[i].name);

        printf("Enter School Name: ");

        scanf("%s", s[i].school);

        printf("Enter District: ");

        scanf("%s", s[i].district);

        }

        printf("\nStudent Information:\n");

        printf("ROLL\tNAME\tSCHOOL\tDISTRICT\n");

        for (i = 0; i < 15; i++)

        {

        printf("%d\t%s\t%s\t%s\n", s[i].roll, s[i].name, s[i].school, s[i].district);

        }

    getch(); 

}

Example Output:

Enter details for student 1:

Enter Roll Number: 101

Enter Name: Madhav

Enter School Name: Usha

Enter District: Surkhet

 

Enter details for student 2:

Enter Roll Number: 102

Enter Name: Suman

Enter School Name: Sasa

Enter District: Pokhara

.........

 

Student Information:

ROLL    NAME       SCHOOL      DISTRICT

101      Madhav    Usha            Surkhet

102      Suman       Sasa             Pokhara

........
OR
Explain call by value and call by reference. Write a C program to swap two numbers using call by reference. [4+4]

Ans:

Call by Value:

Definition: A method of passing arguments to a function where the actual value of the argument is copied to the function's parameter.

Effect: Changes made to the parameter within the function do not affect the original variable.

Usage: Suitable for small or simple data types where modifying the original data is not required.

Call by Reference:

Definition: A method of passing arguments to a function where the reference (address) of the argument is passed to the function's parameter.

Effect: Changes made to the parameter within the function affect the original variable.

Usage: Suitable for large or complex data types where modifying the original data is required.

 

A C program to swap two numbers using call by reference is as follows:

#include <stdio.h>

#include <conio.h>

void swap(int *a, int *b);         // Function declaration

void main() 

{

    int a, b;  

    clrscr(); 

    printf("Enter 1st number:");

    scanf("%d", &a);

    printf("Enter 2nd number:");

    scanf("%d", &b);

    swap(&a, &b);             // Call by reference

    printf("\nValue of 1st number after swap: %d", a);

    printf("\nValue of 2nd number after swap: %d", b);

    getch(); 

}

void swap(int *a, int *b)         // Function definition

{

    int temp;

    temp = *a;

    *a = *b;

    *b = temp;

}

Example Output:

Enter 1st number: 5

Enter 2nd number: 10

Value of 1st number after swap: 10

Value of 2nd number after swap: 5