Computer Applications Specimen Paper 2020 Solved

Section A (40 Marks)

Question 1
a) Define encapsulation.
Encapsulation refers to wrapping up of the characteristics, state and behavior of an entity in a single unit.
b) Explain the purpose of using a ‘new’ keyword in a Java program.
The ‘new’ keyword instantiates a class by allocating memory for a new object.
c) What are literals?
Literals are data items that are fixed data values.
d) Mention the types of access specifiers.
public, private, protected and friendly.
e) What is constructor overloading?
The process of creating multiple constructors for a class that differ only on constructor signature is called constructor overloading.

Question 2
a) Differentiate between boxing and unboxing.
The process of converting a primitive data type value to its corresponding wrapper class is called boxing. For example, conversion from int to Integer.
The process of converting an object of wrapper class to its corresponding primitive data type value is called unboxing. For example, conversion from Integer to int.
b) Rewrite the following condition without using logical operators:

if(a > b || a > c)
    System.out.println(a);
if(a > b)
    System.out.println(a);
else if(a > c)
    System.out.println(a);

c) Rewrite the following loop using for loop:

while(true)
    System.out.print("*");
for(;;)
    System.out.print("*");

d) Write the prototype of a function search which takes two arguments (a string and a character) and returns an integer value.
int search(String s, char ch)
e) Differentiate between = and == operators.
The = operator is an assignment operator.
The == operator is a relational operator.

Question 3
a) State the number of bytes and bits occupied by a character array of 10 elements.
20 bytes or 160 bits.
b) Differentiate between binary search and linear search techniques.
Binary search can only work on sorted list of data.
Linear search can work on both sorted as well as unsorted list of data.
c) What is the output of the following:
String a = "Java is a programming language\ndeveloped by\t\'James Gosling\'";
System.out.println(a);

Java is a programming language
developed by    'James Gosling'

d) Differentiate between break and System.exit(0).
The break keyword is used to terminate a loop or a switch statement.
System.exit(0) is used to terminate a program.
e) Write a statement in Java for:

Math.sqrt((Math.pow(a + b), 3) / Math.abs(a - b))
f) What is the value of m after evaluating the following expression:
m -= 9 % ++n + ++n / 2; when int m = 10, n = 6;
m = m – (9 % ++n + ++n / 2)
= 10 – (9 % 7 + 8 / 2)
= 10 – (2 + 4)
= 10 – 6
= 4.
g) Predict the output of the following:
(i) Math.pow(25, 0.5) + Math.ceil(4.2)
= 5.0 + 5.0
= 10.0
(ii) Math.round(14.7) + Math.floor(7.9)
15.0 + 7.0
= 22.0
h) Give the output of the following Java statements:
(i) "TRANSPARENT".toLowerCase()
transparent
(ii) "TRANSPARENT".compareTo("TRANSITION")
7
i) Write a Java statement for each to perform the following tasks:
(i) Find and display the position of the last space in a string str.
System.out.println(str.lastIndexOf(' '));
(ii) Extract the second character of the string str.
char ch = str.charAt(1);
j) State the types of errors if any in the following statements:
(i) switch(n > 2)
Syntax error
(ii) System.out.println(100 / 0);
Run-time error

Section B (60 Marks)

Question 4
Anshul Transport Company charges for the parcels of its customers as per the following specifications given below:
Class name: ATransport
Member variables:
String name: to store the name of the customer.
int w: to store the weight of the parcel in kg.
int charge: to store the charge of the parcel.
Member functions:
void accept(): to accept the name of the customer, weight of the parcel from the user (using Scanner class)
void calculate(): to calculate the charge as per the weight of the parcel as per the following criteria:

Weight in Kg Charge per Kg
Up to 10 kg Rs. 25 per kg
Next 20 kg Rs. 20 per kg
Above 30 kg Rs. 10 per kg

A surcharge of 5% is charged on the bill.
void print(): to print the name of the customer, weight of the parcel, total bill inclusive of surcharge in a tabular form in the following format:

Name    Weight    Bill Amount
____    _____    ________

Define the class with the above mentioned specifications, create a main() method, create an object and invoke the member methods.

import java.util.*;
class ATransport{
    String name;
    int w;
    int charge;
    public void accept(){
        Scanner sc = new Scanner(System.in));
        System.out.print("Name: ");
        name = sc.nextLine();
        System.out.print("Weight of the parcel in kg: ");
        w = sc.nextInt();
    }
    public void calculate(){
        if(w <= 10)
            charge = w * 25;
        else if(w <= 30)
            charge = 250 + (w - 10) * 20;
        else
            charge = 450 + (w - 30) * 10;
        charge += (int)(5.0 / 100 * charge);
    }
    public void print(){
        System.out.println("Name\tWeight\tBill Amount");
        System.out.println(name + "\t" + w + "\t" + charge);
    }
    public static void main(String args[]){
        ATransport obj = new ATransport();
        obj.accept();
        obj.calculate();
        obj.print();
    }
}

Question 5
Write a program to input name and percentage of 35 students of class X in two separate one-dimensional arrays. Arrange students’ details according to their percentage in descending order using selection sort method. Display the names and percentages of first ten toppers of the class.

import java.io.*;
class Toppers{
    public static void main(String args[])throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int p[] = new int[35];
        String n[] = new String[35];
        for(int i = 0; i < p.length; i++){
            System.out.print("Name: ");
            n[i] = br.readLine();
            System.out.print("Percentage: ");
            p[i] = Integer.parseInt(br.readLine());
        }
        for(int i = 0; i < p.length; i++){
            int large = p[i];
            int pos = i;
            for(int j = i + 1; j < p.length; j++){ 
                if(p[j] > large){
                    large = p[j];
                    pos = j;
                }
            }
            int temp = p[i];
            p[i] = large;
            p[pos] = temp;
            String t = n[i];
            n[i] = n[pos];
            n[pos] = t;
        }
        System.out.println("Names and Percentages of First 10 Toppers:");
        for(int i = 0; i < 10; i++)
            System.out.println(n[i] + " - " + p[i]);
    }
}

Question 6
Design a class to overload a function sum() as follows:
(i) int sum(int a, int b) to calculate and return the sum of all the even numbers in the range a to b.
Sample Input:
a = 14
b = 16
Sample Output:
Sum = 70
(ii) double sum(double n) to calculate and return the product of the following series:
Product = 1.0 × 1.2 × 1.4 × … × N
(iii) int sum(int n) to calculate and return the sum of only odd digits of the number N.
Sample Input:
N = 43961
Sample Output:
Sum = 13
Write the main() method to create an object and invoke the above methods.

import java.io.*;
class Overload{
    public int sum(int a, int b){
        int s = 0;
        for(int i = a; i <= b; i++){
            if(i % 2 == 0)
                s += i;
        }
        return s;
    }
    public double sum(double n){
        double p = 1.0;
        for(double i = 1.0; i <= n; i += 0.2)
            p *= i;
        return p;
    }
    public int sum(int n){
        int s = 0;
        for(int i = n; i != 0; i /= 10){
            if((i % 10) % 2 == 1)
                s += i % 10;
        }
        return s;
    }
    public static void main(String args[])throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        Overload obj = new Overload();
        System.out.print("a = ");
        int a = Integer.parseInt(br.readLine());
        System.out.print("b = ");
        int b = Integer.parseInt(br.readLine());
        int result = obj.sum(a, b);
        System.out.println("Sum of the range: " + result);
        System.out.print("n = ");
        double n = Double.parseDouble(br.readLine());
        double product = obj.sum(n);
        System.out.println("Product: " + product);
        System.out.print("n = ");
        int num = Integer.parseInt(br.readLine());
        result = obj.sum(num);
        System.out.println("Sum of odd digits: " + result);        
    }
}

Question 7
Using the switch statement, write a menu-driven program to perform the following operations:
(i) To print the value of z where z = (x3 + 0.5x) / y where x ranges from -10 to 10 with an increment of 2 and y remains constant as 5.5.
(ii) To print the Floyd’s Triangle with N rows.
Example:
If N = 5
OUTPUT:

1
2    3
4    5    6
7    8    9    10
11   12   13   14   15
import java.io.*;
class Menu{
    public static void main(String args[])throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("1. Print the value of z");
        System.out.println("2. Floyd's Triangle with N rows");
        System.out.print("Enter your choice: ");
        int choice = Integer.parseInt(br.readLine());
        switch(choice){
            case 1:
            System.out.print("y = ");
            double y = Double.parseDouble(br.readLine());
            for(int x = -10; x <= 10; x += 2){
                double z = (Math.pow(x, 3) + 0.5 * x) / y;
                System.out.print(z + "\t");
            }
            System.out.println();
            break;
            case 2:
            int num = 1;
            System.out.print("N = ");
            int n = Integer.parseInt(br.readLine());
            for(int i = 1; i <= n; i++){
                for(int j = 1; j <= i; j++){
                    System.out.print(num + "\t");
                    num++;
                }
                System.out.println();
            }
            break;
            default:
            System.out.println("Invalid choice!");
        }
    }
}

Question 8
Write a program to input and store integer elements in a double-dimensional array of size 4 × 4 and find the sum of all the elements.

7 3 4 5
5 4 6 1
6 9 4 2
3 2 7 5

Sum = 73
import java.io.*;
class Sum{
    public static void main(String args[])throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int a[][] = new int[4][4];
        int sum = 0;
        System.out.println("Enter 16 integers:");
        for(int i = 0; i < 4; i++){
            for(int j = 0; j < 4; j++){
                a[i][j] = Integer.parseInt(br.readLine());
                sum += a[i][j];
            }
        }
        System.out.println("Sum = " + sum);
    }
}

Question 9
Write a program to input a string and convert it into uppercase and print the pair of vowels and number of pair of vowels occurring in the string.
Example:
INPUT:
“BEAUTIFUL BEAUTIES”
OUTPUT:
Pair of vowels: EA, AU, EA, AU, IE
No. of pair of vowels: 5

import java.io.*;
class Pairs{
    public static void main(String args[])throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Enter the string:");
        String s = br.readLine().toUpperCase();
        int count = 0;
        System.out.print("Pair of vowels: ");
        for(int i = 0; i < s.length() - 1; i++){
            if(s.length() < 2)
                break;
            char ch1 = s.charAt(i);
            char ch2 = s.charAt(i + 1);
            if(isVowel(ch1) && isVowel(ch2)){
                System.out.print(ch1 + "" + ch2 + " ");
                count++;
            }
        }
        System.out.println("\nNo. of pair of vowels: " + count);
    }
    public static boolean isVowel(char ch){
        switch(ch){
            case 'A':
            case 'E':
            case 'I':
            case 'O':
            case 'U':
            return true;
            default:
            return false;
        }
    }
}

7 thoughts on “Computer Applications Specimen Paper 2020 Solved”

  1. Sir,a program is given which states that:
    A sphenic number is a positive number which has exactly 3 prime factors.
    Eg: 30,42,66,70,78,etc
    WAP in JAVA to accept a number and check whether it is a sphenic number or not.
    Sample Input:30
    Sample output:30 is a sphenic number.
    Hint:2 x 3 x 5
    It is the product of 3 prime numbers.

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