NEB Preparation Examination - 2081
Subject: Computer Science
Grade 12
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 x 1 = 9 ]
1) Which of the following is not an example of DBMS?
a. MySQL b. Google c. IBM DB2
d. MS- Access
2) Correct code to display “Scripting Language”?
a. System.out.println
b. println
c. response.write d.
document.write
3) What will be the output of following JavaScript code?
var A= "ABC";
var B="College";
document.write(A+B);
a. ABC b. ABCCollege c.
ABC Collegee d. CollegeABC
4) What is the output of given C program?
int a = 9 , b = 42;
printf("%d",a>b);
printf("%d",a<b);
a. 0 0 b. 0 1 c. 1 0 d. 1 1
5) IoT stands for...
a. Internet of Thumb b. Internal of things
c. Internet of though d. Internet
of things
6) What identifies a row in a table as unique?
a. Main Key b. Regular Key
c. Primary Key
d. Foreign Key
7) Hardware component without which a computer cannot be connected over a
network.
a. Modem b.
Router
c. NIC d. Bridge
8) ..................is a process where you show only
"relevant" data and "hide" unnecessary details of an object
from the user.
a. Abstraction b. Polymorphism
c. Inheritance d. Encapsulation
9) ... ... ... is the use of various services, such as
software development platforms, servers, storage, and software, over the
Internet.
a. SDLC b.
e-commerce
c. e-business d. Cloud Computing
Group B - Short answer Questions
Short answer questions. [5×5=25]
10. What is data security? How it can be implemented? [2+3]
Ans: Data security refers to the protection of data from unauthorized
access, use, disclosure, disruption, modification, or destruction. It aims to
ensure the confidentiality, integrity, and availability of information.
Data security can be implemented through various measures as:
- Access
Control: Using
passwords, biometrics, and permissions to restrict who can access data.
- Encryption: Converting data into an
unreadable format to protect it during storage and transmission.
- Firewalls: Creating a barrier between
trusted and untrusted networks to block malicious traffic.
- Intrusion
Detection and Prevention Systems: Monitoring network activity for suspicious behavior and
taking action to prevent attacks.
- Regular
Backups:
Creating copies of data to allow for recovery in case of data loss.
- Security
Audits:
Regularly assessing security measures to identify vulnerabilities and
ensure effectiveness.
- Employee
Training:
Educating users about security best practices and potential threats.
OR
Differentiate
between client-server and peer-to-peer architecture.
Ans:
|
Client-Server
Network |
Peer-to-Peer
Network |
|
Data is typically
stored in a centralized server. |
Every peer holds its
own data. |
|
In a Client-Server
network, the server responds to the service requests made by the client. |
In a Peer-to-Peer
network, each node can both request and provide services. |
|
A Client-Server
network is more expensive than a Peer-to-Peer network. |
A Peer-to-Peer network
is more cost-effective than a Client-Server network. |
|
They provide a more
stable network configuration. |
They offer less
stability in comparison. |
|
They can be employed
in both small and large networks. |
They are mainly used
for smaller networks. |
11. What is JavaScript? Write a function to multiply any two numbers in JavaScript.
Ans: JavaScript is a dynamic, interpreted, and high-level programming
language primarily used to add interactivity to web pages. It allows us to
create dynamically updating content, control multimedia, animate images, and
much more, enhancing the user experience.
<html>
<head>
<title>javascript</title>
<script>
function multiply(a,b){
const m=a*b;
document.write("Mulitplication
of two number= "+m);
}
</script>
</head>
<body>
<script>
var a=
parseInt(prompt("Enter first number"));
var b =
parseInt(prompt("Enter Second number"));
multiply(a,b);
</script>
</body>
</html>
OR
Write a
JavaScript program to check whether the given number is prime or composite. (5)
Solution:
<html>
<head>
<title>javascript</title>
<script>
var c=0;
function
primecomposite(n){
for(var i=1;
i<=n;i++){
if (n%i ==0){
c++;
}}
if (c<=1){
document.write("Neither
prime or composite");
}else if (c==2){
document.write("Number
is prime");
}else{
document.write("Number
is composite");
}}
</script>
</head>
<body>
<script>
var n=
parseInt(prompt("Enter a number"));
primecomposite(n);
</script>
</body>
</html>
12. Explain the last two stages of system development life cycle.
Ans: The last two stages of SDLC are:
1. Implementation (Deployment)
o The developed system is installed and
made operational.
o Data migration from old to new system
occurs.
o User training is provided.
o Types: Direct, Parallel,
Phased, Pilot cutover.
2. Maintenance & Support
o Fixing bugs and improving performance.
o Regular updates and security patches.
o User feedback is incorporated for
enhancements.
o Continues until the system is
replaced or retired.
13. Explain the different characteristics of Object-oriented Programming
(OOP)?
Ans: The different characteristics of Object-oriented programming are:
1. Objects: Objects are the fundamental building blocks of OOP. They are
instances of classes and represent real-world entities or abstract concepts. An
object encapsulates both data (attributes) and the methods (behavior) that
operate on that data.
2. Classes: A class is a blueprint or a template that defines the
structure and behavior of objects of that type. It specifies the attributes
(data members) that an object will have and the methods (member functions) that
an object can perform.
3. Encapsulation: This principle bundles data (attributes) and methods
(functions) that operate on that data into a single unit called a class or
object. This bundling hides the internal implementation details from the
outside world, protecting the data and promoting modularity.
4. Inheritance: This principle allows classes to inherit properties and
methods from other classes (parent or superclass). This promotes code
reusability and reduces redundancy.
5. Polymorphism: This principle enables objects of different classes to
respond to the same method call in their own specific ways. This allows
for flexibility and adaptability in code.
6. Abstraction: This principle simplifies complex reality by focusing on
essential features and hiding unnecessary implementation details. This
makes the code easier to understand and use.
14. Define IOT and Big data with its advantage.
Ans: The Internet of Things (IoT) describes a network
of physical objects ("things") embedded with sensors, software, and
other technologies that enable them to collect and exchange data over the
internet.
Advantages of IoT are:
1. It increases the efficiency and
productivity of work.
2. It helps to automate our daily life
work.
3. It can be used as entertainment
enhancing user experience.
4. It helps to communicate and exchange
data and information in real-time.
Big
data
refers to massive, diverse datasets that are difficult to manage using
traditional database tools. It's characterized by volume, variety,
velocity, and variability. The main advantage of big data is the
ability to gain insights and improve decision-making across various
industries.
Advantages
of Big Data are:
1. Enables
predictive analytics and trend analysis.
2. Helps businesses
tailor products/services to customer preferences.
3. Identifies
unusual patterns and behaviors in real-time.
4. Optimizes supply
chains, inventory, and processes.
5. Supports new
product development and strategic planning.
Group C - Long answer Questions
Long answer questions. [8×2=16]
15. What do you mean by topology? Explain Bus, Star and Ring Topology
with their diagrams. (2+6)
Ans: Topology refers to the physical or logical arrangement of
nodes and the connections between them in a network. It defines the structure
of how data is transferred within the network. The choice of topology can
significantly impact the network's performance, reliability, and cost.
1. Bus Topology: In a bus topology, all devices in the network are connected
to a single cable, called the bus or backbone. Data is transmitted along this
bus, and all devices on the network receive the signal. However, only the
device with the intended address will process the data. A terminator is placed
at each end of the bus to prevent signal reflection.
Advantages:
· Easy to set up and cost-effective.
· Requires less cabling.
Disadvantages:
· If the main cable fails, the entire network
goes down.
· Performance degrades with heavy
traffic.
2. Star Topology: In a star topology, all devices in the network are connected
to a central hub or switch. All communication between devices passes through
this central point. A device wanting to communicate with another device sends
the data to the hub/switch, which then forwards it to the intended destination.
Advantages:
· If one cable or device fails, the
rest of the network remains unaffected.
· New devices can be easily added by
connecting them to the central hub/switch.
Disadvantages:
· If the central hub or switch fails,
the entire network goes down.
· Requires more cable and a central
connecting device (hub or switch), which can be expensive.
3. Ring Topology: In a ring topology, each device is connected to exactly two
other devices, forming a closed loop or ring. Data travels around the ring in
one direction, from one device to the next, until it reaches the intended
destination. Each device acts as a repeater, forwarding the signal to the next
device in the ring.
Advantages:
· No data collisions (orderly
transmission).
· Works well under heavy traffic.
Disadvantages:
· A single node failure can break the
entire loop.
· Adding/removing nodes disrupts the
network.
16. Write a C program to store registration number, name and marks of 3 subjects
using structure and display them in ascending order on the basis of
registration number. (8)
Solution:
#include <stdio.h>
#include<conio.h>
#include <string.h>
struct Student {
int regNo;
char name[50];
float marks[3];
};
void main() {
int n, i, j;
printf("Enter the number
of students: ");
scanf("%d", &n);
struct Student stu[n], temp;
for (i = 0; i < n; i++) {
printf("\nEnter
details for student %d:\n", i + 1);
printf("Registration
Number: ");
scanf("%d",
&stu[i].regNo);
printf("Name: ");
scanf("%s",
stu[i].name);
printf("Marks of 3
subjects: ");
scanf("%f %f %f",
&stu[i].marks[0], &stu[i].marks[1], &stu[i].marks[2]);
}
for (i = 0; i < n ; i++) {
for (j = 0; j < n; j++)
{
if (stu[j].regNo >
stu[j + 1].regNo) {
temp = stu[j];
stu[j] = stu[j +
1];
stu[j + 1] = temp;
}
}
}
printf("\nStudent Details
(Sorted by Registration Number):\n");
printf("Reg
No\tName\t\tMarks (Sub1, Sub2, Sub3)\n");
for (i = 0; i < n; i++) {
printf("%d\t%s\t\t%.2f,
%.2f, %.2f\n",
stu[i].regNo,
stu[i].name,
stu[i].marks[0],
stu[i].marks[1],
stu[i].marks[2]);
}
getch();
}
OR
Write a
program in C to create a data file “score.txt” which stores Student ID, Name,
marks of computer as per need of user. After that display all the records of
file “score.txt”. (8)
Solution:
#include <stdio.h>
#include<conio.h>
struct Student {
int id;
char name[50];
float
computerMarks;
};
int main() {
FILE *ptr;
int n, i;
ptr =
fopen("score.txt", "w");
printf("Enter
the number of students: ");
scanf("%d", &n);
struct Student s;
for (i = 0; i <
n; i++) {
printf("\nEnter details for student %d:\n", i + 1);
printf("Student ID: ");
scanf("%d", &s.id);
printf("Name: ");
scanf("%s", s.name);
printf("Computer Marks: ");
scanf("%f", &s.computerMarks);
fprintf(ptr,
"%d %s %.2f\n", s.id, s.name, s.computerMarks);
}
fclose(ptr);
printf("\nDisplaying records from score.txt:\n");
printf("ID\tName\tComputer Marks\n");
ptr =
fopen("score.txt", "r");
while (fscanf(ptr,
"%d %s %f", &s.id, s.name, &s.computerMarks) != EOF) {
printf("%d\t%s\t%f\n", s.id, s.name, s.computerMarks);
}
fclose(ptr);
return 0;
}
The End