Class 12 computer model questions with solutions
MODEL QUESTIONS
Grade: XII
Subject: Computer
Full Marks: 50
Time: 2 hrs.
Group
A
Rewrite the correct options of each
question in your answer sheet. (9x1=9)
1. In which normal form of database,
atomicity is introduced?
A) First
B) Second
C) Third
D) Fourth
2. Which of the following techniques
is not implemented to protect a database?
A) Rollback
B) Backup
C) Recovery
D) Firewall
3. 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”;
4. 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
5. Which of the following is a
server-side scripting language?
A) JavaScript
B) MySql
C) PHP
D) Jquery
6. 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
7. 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
8. 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.
9. Which of the following feasibility
study is concerned with cost benefit analysis?
A) Technical feasibility
B) Economic feasibility
C) Operational feasibility
D) Schedule feasibility
Group B
Short Answer
Questions
10. Which type of
database system (centralized or distributed) is mostly preferred by financial
institution like a bank? Give any four suitable reasons.
Financial institutions like banks mostly prefer a
centralized database system due to the following reasons:
- Ø Security: Centralized database systems are easier to secure as they have a
single point of control, making it easier to implement access controls and
monitoring.
- Ø Consistency: With a centralized system, data is stored in one location,
ensuring consistency and reducing the possibility of data inconsistencies.
- Ø Easy maintenance: Maintenance is easier in a centralized system as there is
only one database to maintain and backup, making it easier to perform updates,
upgrades, and backups.
- Ø Cost-effective: Centralized systems can be more cost-effective as there are
no additional costs associated with distributing data across multiple locations
and servers.
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.
The relational model is the
most widely used database model in modern business organizations for various
reasons:
- Ø Simplicity: The relational model is easy to understand and use, which makes
it suitable for developers with different levels of experience to design and
maintain databases.
- Ø Flexibility: The relational model can store data in different formats and
structures, making it suitable for diverse data types and use cases.
- Ø Standardization: The relational model has become a de facto standard for
database design, which ensures consistency and compatibility across different
systems and organizations.
- Ø Scalability: The relational model can accommodate a growing amount of data
and user traffic, making it suitable for organizations of all sizes.
- Ø Security: The relational model provides built-in security features such as access control, data encryption, and data integrity checks, which ensure that sensitive data is protected.
11. Develop a
program in JavaScript to exchange/swap the values of any two variables.
// Define two variables
let a = 5;
let b = 10;
// Print the original values
document.write("Before swapping,
a = " + a + " and b = " + b + "<br>");
// Swap the values using a temporary
variable
let temp = a;
a = b;
b = temp;
// Print the new values
document.write("After swapping,
a = " + a + " and b = " + b);
OR
How can you connect
a database with PHP? Demonstrate with an example.
Solution:
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
$conn = new mysqli($servername,
$username, $password, $dbname);
if ($conn->connect_error)
{
die("Connection failed: " .
$conn->connect_error);
}
$conn->close();
?>
12. Describe the concept
of Object Oriented and Procedure Oriented Programming in brief.
Object Oriented Programming
(OOP) is a programming paradigm that focuses on objects and their interactions
with each other. It emphasizes data rather than procedures and supports
abstract data types, inheritance, and polymorphism.
Procedure Oriented Programming
(POP) is a programming paradigm where the program is written as a sequence of
procedures or functions that manipulate data. The focus is on procedures rather
than data, and the flow of execution is determined by function calls.
Following are the features
of OOP
- Ø Encapsulation
- Ø
Inheritance
- Ø
Polymorphism
- Ø Abstraction
- ØClasses and Objects
13. Write down any
five qualities of good software.
- Ø Functionality: Software must fulfill its intended purpose effectively and
efficiently.
- Ø Reliability: Software must operate consistently without any errors and
prevent data loss.
- Ø Maintainability: Software must be easily modifiable and supportable.
- Ø Usability: Software must have a user-friendly interface.
- Ø Efficiency: Software must be able to handle large data processing without
significant delays or system crashes.
14. Explain mobile
computing with its advantages and disadvantages.
Mobile computing
refers to the use of portable devices, such as smartphones, tablets, and
laptops, to access and process data and applications while on the move.
Advantages of mobile
computing:
- Ø Portability: Users can access information and applications from anywhere
and anytime.
- Ø Connectivity: Mobile devices can be connected to wireless networks,
cellular networks, or the internet.
- Ø Convenience: Mobile computing allows users to stay connected and productive
on the go.
- Ø Efficiency: Mobile devices can perform tasks quickly and easily, reducing
the need for paper-based processes.
- Ø Cost savings: Mobile devices are often cheaper than traditional desktops or
laptops.
Disadvantages of
mobile computing:
- Ø Security: Mobile devices can be more vulnerable to security threats such as
viruses and malware.
- Ø Battery life: Portable devices have limited battery life, which can be a
problem when using them for extended periods of time.
- Ø Compatibility: Some applications may not work properly on all devices,
leading to compatibility issues.
- Ø Limited processing power: Mobile devices have limited processing power and memory compared to desktops and laptops.
- Ø Small screen size: The small screen size of mobile devices can be a limitation when working with complex applications or large amounts of data.
Group C
Give
the long answers to the following questions.
15.
Why do most of the business organizations prefer setting their network with the
client-server architecture? Write its advantages and disadvantages.
Most business
organizations prefer setting their network with the client-server architecture
due to its various advantages. Some of the advantages are:
Advantages:
- Ø Centralized control: Client-server architecture allows centralized control,
making it easy to manage and maintain the network.
- Ø Improved security: The client-server architecture offers improved security
as all data and resources are stored on the server, which can be easily secured
and backed up.
- Ø Scalability: It is easy to scale the network in a client-server
architecture by adding more servers or clients.
- Ø High-performance: Client-server architecture offers high-performance as the
processing is done on the server, which is usually more powerful than clients.
However, there are
also some disadvantages to the client-server architecture, such as:
Disadvantages:
- Ø Cost: The cost of setting up and maintaining a client-server architecture
can be high.
- Ø Dependency: Client-server architecture is dependent on the server, and if
the server goes down, the clients cannot access the network.
- Ø Network congestion: Network congestion can occur in a client-server
architecture as all requests have to go through the server.
- Ø Complexity: Client-server architecture can be complex to set up and
maintain, requiring skilled IT professionals.
16.
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].
#include
<stdio.h>
struct
student {
int roll_number;
char name[50];
int sub1, sub2, sub3;
float total, percentage;
}s[12];
int
main()
{
int i;
for (i = 0; i < 12; i++)
{
printf("Enter the roll number of
student ");
scanf("%d", &s[i].roll_number);
printf("Enter the name of student");
scanf("%s", s[i].name);
printf("Enter the marks of subject
1 for student ");
scanf("%d", &s[i].sub1);
printf("Enter the marks of subject
2 for student ");
scanf("%d", &s[i].sub2);
printf("Enter the marks of subject
3 for student ");
scanf("%d", &s[i].sub3);
s[i].total = s[i].sub1 + s[i].sub2 + s[i].sub3;
s[i].percentage = (s[i].total / 300) *
100;
}
printf("Roll No. , Name ,Subject 1 ,
Subject 2 ,Subject 3 ,Total ,Percentage\n");
for (i = 0; i < 12; i++)
{
printf("%d %s %d %d %d %f %f
\n", s[i].roll_number, s[i].name, s[i].sub1, s[i].sub2, s[i].sub3,
s[i].total, s[i].percentage);
}
return 0;
}
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