Class 12 Computer Science

2. Which database system normally offers better performance for geographically dispersed users?

A) Centralized database system      B) Distributed database system   

  C) NoSQL database system            D) Relational database system

5. Which PHP function is commonly used to execute SQL queries on a database connection established using mysqli extension?

A) mysqli_query()   B) pdo_query()

C) mysql_query()    D) pgsql_query()

10. Evaluate the advantages of DBMS compared to traditional file-based data storage systems. 

                                                             OR

    How does Second Normal Form (2NF) differ from First Normal Form (1NF), and what are the key benefits of achieving 2NF in database design? Explain.

11. Write a JavaScript function that checks if a number is even or odd and print the result.

                                 OR

             What is purpose of the mysqli_connect( ) function in PHP? Describe its usage and parameters.

Which of the following is DML statement?

 (A) Create     (B) Select       (C) Create view Alter    (D) Drop

Which function is used to connect to mySQL database?

(A) mysqli_open ( )     (B) mysqli_connect ( )      (C) var mysqli_query ( )      (D) $mysqli_con ( )

Explain the Relational Data model with example. 

 OR

Write SQL DDL commands to execute the following task with reference to the schema given below:

student_info (regno as integer, name as character (25), class integer, gender character (1), address character (25).

Define a syntax for database connectivity. Write a server side scripting code to insert data into the table student having fields (first name, last name, mark and email:) Assume that server name="localhost", username="root", password="", database name="student DB".

OR

Write a JavaScript code to calculate the factorial of a given number

In which normal form of database, atomicity is introduced?

A) First      B) Second C) Third D) Fourth

Which of the following techniques is not implemented to protect a database?

 A) Rollback      B) Backup        C) Recovery       D) Firewall

Which one of the following SQL commands is executed to display all the records having a second letter in the LNAME (LAST NAME) as "A" from the customer table?

A) SELECT * FROM CUSTOMER WHERE LNAME LIKE "?A%";

B) SELECT * FROM CUSTOMER WHERE LNAME LIKE "_A%";

C) SELECT * FROM CUSTOMER WHERE LNAME LIKE "A%";

D) SELECT * FROM CUSTOMER WHERE LNAME LIKE "%A";     

Which type of database system (centralized or distributed) is mostly preferred by financial institution like a bank? Give any four suitable reasons. 

 OR

 Nowadays most of the business organizations prefer applying relational model for database design in comparison to other models. Justify the statement with your arguments. 5

Records in database are also known as
A) Data      B) Fields     C) Tuples        D) Keys

Which SQL statement displays the name and address of all students who live either in Kathmandu or Bhaktapur from students table ?
A) SELECT *FROM students WHERE address = "Kathmandu" or address = "Bhaktapur";
B) SELECT name, address FROM Students WHERE address = "Kathmandu" or "Bhaktapur";
C) SELECT *FROM students WHERE address = "Kathmandu" or "Bhaktapur";
D) SELECT name, address FROM students WHERE address = "Kathmandu" or address = "Bhaktapur";

Compare the hierarchical database model and the relational database model. Write two advantages of each model.

Which of the following is the purpose of using primary key in database?
A) To uniquely identify a record
B) To store duplicate record
C) To backup data
D) To enhance database size

A company needs to modify an existing table by adding a new column for employee email addresses. For this, which SQL command should be used?
A) CREATE      B) ALTER       C) SELECT              D) UPDATE

 Write any three differences between DDL and DML. Give examples of each. 

OR 

What is normalization? Explain 2NF and 3NF. 

Write JavaScript code to input any three numbers and find the smallest number among them. 

OR 

Write a PHP script to connect to a MySQL database. 

A collection of hyperlinked documents on the Internet is called:

(A) HTML     (B) webpage    (C) www    (D) email system

Which of following IPV4 address valid?

(A) 192.168.1.1     (B) EEE.000.33.000    (C) 257.2.5.1    (D) 202.70.71.262

What is network topology? Differentiate between guided (wire media) and unguided (wireless media) with example.

Which of the following is an incorrect IP address?

A) 192.168.0.1         B) 192.168.1      C) 172.255.0.0    D) 202.10.79.4

Explain mobile computing with its advantages and disadvantages.

Why do most of the business organizations prefer setting their network with the client-server architecture? Write its advantages and disadvantages.

The full form of OSI is
A) Open Service Implementation
B) Open System Internet
C) Open Service Interconnection
D) Open System Interconnection

A device automatically adjusts room temperature based on real time sensor data and internet connectivity. Which technology does this represent ?
A) Desktop computing                      B) Cloud storage
C) IoT (Internet of Things)                D) Traditional Embedded System

Explain the basic concept of cloud computing with any three advantages.

Explain twisted pair cable, coaxial cable and optical fibre cable.

Which protocol is used for secure communication over a computer network?
A) HTTP
B) FTP
C) HTTPS
D) Telnet

Which of the following is NOT a type of cloud computing service?
A) Infrastructure as a Service (IaaS)         B) Platform as a Service (PaaS)
C) Software as a Service (SaaS)               D) Hardware as a Service (HaaS)

 What is transmission medium? Explain its major types with advantages and disadvantages.

4. What is the correct syntax for a 'for-loop' in JavaScript?

 A) for (var i = 0; i < 5; i++) {}    B) for (i = 0; i < 5; i++) {}

C) for (var i = 0; i < 5) {}      D) for (var i < 5; i++) {}

14. Give five examples of AI applications in the education.

1. Which of the given sign is used as a shortcut for JQuery?

 (A) the % sign

(B) the & sign

(C) the $ sign

 (D) the @ sign

Which jQuery method is used to hide selected elements?

 (A) hide ( ) (B) hide (on) (C) invisible ( ) (D) display (none)

Which of the following is a server-side scripting language?

 A) JavaScript     B) MySql     C) PHP     D) Jquery

Which of the following keywords are used to declare a variable in JavaScript?

A) int or var     B) float or let     C) var or let    D) char or var

Which of the following commands is executed in PHP to concatenate the variables $x with $y?

 A) $x + $y        B) $x=$y     C) concat ($x,$y)      D) $x.$y

Develop a program in JavaScript to exchange/swap the values of any two variables. 

 OR

 How can you connect a database with PHP? Demonstrate with an example. 

Which JavaScript method is used to write HTML output ?
A) document.write ( )      B) document.output ( )     C) console.log ( )      D) document.write HTML ( )

What will be the output of the following PHP code ?
<?php $a = 10; $b = 5;
echo $a%$b; ?>
A) 0                            B) 1                            C) 2                            D) 5

What does ++X do in a C program ?
A) Returns value then increments
B) Increments then return value
C) Decrement value
D) Returns original value

Write a JavaScript program that accepts three numbers as input and find smallest among them.

 Which control structure in JS (Java Script) is used to execute a block of code repeatedly based on a given condition?
A) For loop         B) if-else           C) switch – case              D) function

Select the invalid variable name in PHP.
A) $name      B) $_name        C) $1name            D) $name123

What is AI? Explain application areas of AI in education.

6. What is the correct syntax to declare a structure in C?

A) struct { }   B) define struct { } 

C) struct [ ]  D) struct <name> { }

7. In C, which operator is used to get the address of a variable?

A) *         B) &  

C) ->          D) .

16. Write a C program that uses structures to represent details of five books (title, author, publisher and price) and prints them out. 

                                   OR

       Discuss the concept of binary file handling in C programming and explain how putw( ) and getw( ) functions facilitate binary input/output operations. Give examples.

 Which of the following is true about FILE fpt?

 (A) FILE is a keyword in c for representing files and fpt is a variable of FILE type

(B) FILE is a buffered Stream.

(C) FILE is a Stream.

(D) FILE is a structure and fpt is a pointer to the structure of FILE type.

Write the advantage of pointer. Write a C-program to enter the radius of a football and find the area of football by using user defined function. 

 OR

Define the structure. Write a C-program using structure to input staff id, name and the salary of 50 staffs. Display staff id, name and salary of those staff whose salary range from 25 thousand to 40 thousand. 

a) Write a C program to input a number and check whether it is positive or negative or zero using user-defined function. 

b) Write a C program to generate the Fibonacci series of the first two numbers, 7 and 14, up to 10 terms using a user-defined function. 

 The statement int number ( int a); is a …
A) function call      B) function definition     C) function declaration      D) function execution

Write a C program that reads the account_number, name and address of ten customers from users and displays the account_number, name and address of these customers using Array and structure. 

OR 

What are the components of a function of C?
Describe the Call – by – value and Call – by – reference and passing the function parameters. 

 1) Which one of the followings given statement correct?

A) Select * from enp where eopid = 103;        B) Select from enp where eopid = 103;

C) Select eopid where enp = 103 from emp;           D) Select eopid where eopid = 103 and table = emp;

8. Which OOP feature allows a class to inherit properties and behavior from another class?

A) Inheritance       B) Encapsulation

 C) Polymorphism  D) Abstraction

12. Write short note on class and object in OOPs with a real-word example.

How is even-driven program (or OOP) differing from procedural-oriented programming? Explain.

Which statement is incorrect about the object-oriented approach?

 A) Emphasis is on data rather than procedure.

B) Data is hidden and cannot be accessed.

C) Objects communicate through functions.

D) It supports abstract data but not the class.

Describe the concept of Object Oriented and Procedure Oriented Programming in brief.

Develop a program in C using structure to ask the information of any 12 students with roll_number, name and marks scored in sub1, sub2, and sub3. Also, display them in proper format along with the calculation of total and percentage. [Note: the full marks of each subject is 100].

 OR

Demonstrate a program in C to create a data file named score.dat to store students' information with Reg_no, name, gender, and address. The program should ask the user to continue or not. When finished, the program should also display all the records in the proper format.

Which of the following feature to allow the same method name to be used for different types/number of parameters in OOPs, concept ?
A) Abstraction                                  B) Encapsulation
C) Polymorphism                               D) Inheritance

What is OOP (Object Oriented Programming) ? Describe any four features of OOP.

 In which of the following programming, the emphasis is given on data rather than on procedures?
A) Procedural programming       B) Structural programming     C) Object-oriented programming    D) Declarative programming

Write short notes on class and inheritance in oops with example.

9. Which model of SDLC is characterized by a linear progression of phases from requirements gathering to maintenance?

 A) Waterfall model    B) Agile model   

C) Spiral model     D) RAD model

13. How do various requirement gathering techniques help in achieving a careful grasp of user needs and system requirements during SDLC's analysis phase? 

Which a SDLC phase is used to ensure quality software?

 (A) implementation (B) maintenance (C) testing (D) system study

Explain the importance of the system testing of the system development life cycle (SDLC).

Which of the following feasibility study is concerned with cost benefit analysis?

 A) Technical feasibility   

B) Economic feasibility

C) Operational feasibility

D) Schedule feasibility

Write down any five qualities of good software.

Which model follows a strict linear sequential phase order ?
A) Agile                                           B) Waterfall
C) Prototype                                     D) Scrum

Explain about technical and economic feasibility.

Which type of feasibility study evaluates whether a system can be developed with the available technology?
A) Operational feasibility     B) Social feasibility
C) Technical feasibility        D) Economic feasibility

What is Requirement Gathering? Explain different Requirement Gathering methods.

3. Which of the following is an example of a public IPv4 address?

 A) 192.168.1.1      B) 172.16.10.1

C) 10.10.10.10      D) 203.0.113.10

15. How does the star network topology differ from the bus network topology in terms of its architectural layout and data transmission methodology in modern computing environments? [

Coaxial cable is an example of...

 A) Communication software

B) Guided Transmission media

C) Unguided Transmission media

D) All of them

What is cloud computing? Point out the advantage and disadvantage of cloud computing.