ICSE Solved Paper, 2017 ~ A2Z Computer

ICSE Examination 2017 – 18 (Solution)

COMPUTER APPLICATION
Class – X
SECTION – A (40 MARKS)
Attempt all questions

Question 1:

(a) What is Inheritance? [2]

Ans: - Inheritance is the process by which one class extends another class to inherit the variables and functions and add any additional variables and methods.

(b) Name the operators listed below: [2]

i) <

ii) ++

iii) &&

iv)? :

Ans: - i) < – Less than relational operator

ii) ++ – increment operator

iii) && – Logical AND operator

iv) ? : – Ternary operator

(c) State the number of bytes occupied by char and int data types. [2]

Ans: - char occupies two bytes and int occupies 4 bytes.

(d) Writ one difference between / and % operator. [2]

Ans: - / division operator which gives quotient while % is modules operator which gives the remainder on dividing two numbers.

(e) String x[] = {“SAMSUNG”, “NOKIA”, “SONY”, “MICROMAX”, “BLAKBERRY”}; [2]

Give the output of the following statements:

i) System.out.println(x[1]);

ii) System.out.println(x[3].length());

Ans: - i) NOKIA

ii) “MICROMAX”.length()

= 8

Question 2:

(a) Name of the following:

i) A keyword used to call a package in the program.

ii) Any one reference data types.

Ans: - i) import

ii) String

(b) What are the two ways of invoking functions? [2]

Ans: - Call by value and Call by reference

(c) State the data type and value of res after the following is executed:

char ch = 't';

res = Character.toUpperCase(ch); [2]

Ans: - Data type of res is char and value is T

(d) Give the output of the following program segment and also mention the number of times the loop is executed: [2]

int a,b;

for(a=6,b=4;a<=24;a=a+6)

{

if(a%b==0)

break;

}

System.out.println(a);

Ans: - The output is 12 and loop is executed 2 times.

(e) Write the output: [2]

char ch= 'F';

int m=ch;

m=m+5;

System.out.println(m+ " " +ch);

Ans: - 75 F

Question 3:

(a) Write a Java expression for the following: [2]

Ans: - a * Math.pow(x, 5) + b *b Math.pow(x, 3) + c

(b) What is the value of x1 if x = 5? [2]

x1 = ++x – x++ + – –x

Ans: x1 = ++x – x++ + – –x

x1 = 6 – 6 + 6

x1 = 6

(c) Why is an object called an instance of a class? [2]

Ans: - An object is called an instance of a class as every object created from a class gets its own instances of the variables defined in the class. Multiple objects can be created from the same class.

(d) Convert following do-while loop into for loop. [2]

int i=1;

int d=5;

do{

d=d*2;

System.out.println(d);

i++;

}while(i<=5);

Ans: for(int i=1, d=5; i<=5; i++)

{

d = d * 2;

System.out.println(d);

}

(e) Differentiate between constructor and function. [2]

Ans: - (i) The constructor of a class is invoked automatically during object creation while a function is invoked manually after object creation.

(ii)A constructor is invoked only once while a function can be invoked multiple times.

(iii) A constructor has the same name as the class in which it is defined while a function can have any time.

(f) Write the output of the following: [2]

String s= "Today is Test";

System.out.println(s.indexOf('T'));

System.out.println(s.substring(0,7)+ " "+ "Holiday");

Ans: - 0

Today i Holiday

(g) What are the values stored in variables r1 and r2: [2]

i) double r1 = Math.abs(Math.min(–2.83, –5.83));

ii) double r2 = Math.sqrt(Math.floor(16.3));

Ans: - i) 5.83

ii) 4.0

(h) Give the output of the following code: [2]

String A= "26", B= "100" ;

String D=A+B+ "200";

int x= Integer.parseInt(A);

int y=Integer.parseInt(B);

int d=x+y;

System.out.println("Result 1=" +D);

System.out.println("Result 2="+d);

Ans: - Result 1 = 26100200

Result 2 = 126

(i) Analyze the given program segment and answer the following questions: [2]

for(int i=3;i<=4;i++){

for(int j=2;j<i;j++){

System.out.print(" ");

}

System.out.println("WIN");

}

(i) How many times does the inner loop execute?

(ii) Write the output of the program segment.

Ans: - i) 3 times

ii) WIN

WIN

(j) What is the difference between the Scanner class functions next() and nextLine()? [2]

Ans: - next() read a single token i.e. all characters from the current position till a whitespace

or tab or new line is encountered.

nextLine() reads an entire line i.e. all characters from the current position till a new

line is encountered.

SECTION – B (60 MARKS)

Attempt any four questions

Question 4:

Define a class ElectricBill with the following specifications:

class : ElectricBill

Instance variable / data members

String n – to store the name of the customer

int units – to store the number of units consumed

double bill – to store the amount to be paid

Methods

void accept(): to accept the name of the customer and number of units consumed.

void calculate(): to calculate the bill as per the following tariff:

Number of units Rate per unit

First 100 units ₹ 2.00

Next 200 units ₹ 3.00

Above 300 units ₹ 5.00

A surcharged of 2.5% charged if the number of units consumed is above 300 units.

void print(): to print the details as follows:

Name of the customer: ___________

Number of units consumed: ________

Bill amount: __________

Write a main() method to create an object of the class and call the above member functions. [15]

Ans: -

import java.util.*;

class ElectricBill

{

private String n;

private int units;

private double bill;

void accept()

{

Scanner sc = new Scanner(System.in);

System.out.print("Enter name: ");

n = sc.next();

System.out.print("Enter units: ");

units = sc.nextInt();

}

void calculate()

{

if (units <= 100)

bill = units * 2;

else if (units <= 300)

bill = 100 * 2 + (units - 100) * 3;

else

{

bill = 100 * 2 + 200 * 3 + (units - 300) * 5;

double surcharge = bill * 2.5 / 100;

bill = bill + surcharge;

}

public void print()

{

System.out.println("Name of the customer: " + n);

System.out.println("Number of units consumed: " + units);

System.out.println("Bill amount: " + bill);

}

public static void main()

{

ElectricBill ob= new ElectricBill();

ob.accept();

ob.calculate();

ob.print();

}

Question 5:

Write a program to accept a number and check and display whether it is a spy number or not. [15]

A number is spy if the sum of its digits equals the product of its digits.

Example: Consider the number 1124

Sum of the digits = 1 + 1 + 2 + 4 = 8

Product of the digits = 1 × 1 × 2 × 4 = 8

Ans: -

class SpyNumber

{

public static void main(int n)

{

int sumOfDigits = 0;

int productOfDigits = 1;

while (n > 0)

{

int remainder = n % 10;

sumOfDigits = sumOfDigits + remainder;

productOfDigits = productOfDigits * remainder;

n = n / 10;

}

if (sumOfDigits == productOfDigits)

System.out.println("Spy number");

else

System.out.println("Not a spy number");

}

Question 6:

Using switch statement, write a menu driven program for the following: [15]

i) To find and display the sum of the series given below:

ii) To display the following series:

1 11 111 1111 11111

For an incorrect option, an appropriate error message should displayed.

Ans: -

import java.util.*;

class Menu

{

public static void main()

{

System.out.println("1. Sum of series");

System.out.println("2. Display Series");

System.out.print("Enter your choice: ");

Scanner sc = new Scanner(System.in);

int choice = sc.nextInt();

switch (choice)

{

case 1:

double sum = 0;

for (int i = 1; i <= 20; i++)

{

if (i % 2 == 1)

sum = sum + Math.pow(2, i);

else

sum = sum - Math.pow(2, i);

}

System.out.println("Sum = " + sum);

break;

case 2:

for (int i = 1; i <= 5; i++)

{

for (int j = 1; j <= i; j++)

System.out.print("1");

System.out.print(" ");

}

break;

default:

System.out.println("Invalid choice");

}

Question 7:

Write a program to input integer elements into an array of size 20 and perform the following operations: [15]

i) Display largest number from the array

ii) Display smallest number from the array

iii) Display sum of all the elements of the array

Ans: -

import java.util.*;

class ArrayOperations

{

public static void main()

{

Scanner sc = new Scanner(System.in);

int[] numbers = new int[20];

System.out.print("Enter 20 numbers: ");

for (int i = 0; i < 20; i++)

numbers[i] = sc.nextInt();

int smallest = numbers[0];

int largest = numbers[0];

int sum = 0;

for (int i = 0; i < 20; i++)

{

if (numbers[i] < smallest)

smallest = numbers[i];

if (numbers[i] > largest)

largest = numbers[i];

sum = sum + numbers[i];

}

System.out.println("Smallest = " + smallest);

System.out.println("Largest = " + largest);

System.out.println("Sum = " + sum);

}

Question 8:

Design a class to overload a function check() as follows: [15]

i) void check(String str, char ch) – to find and print the frequency of a character in a String.

Example:

str = “success”;

ch = 's';

Output: Number of s present is = 3

ii) void check(String s1) – to display only the vowels from string s1, after converting it to lower case.

Example:

s1 = “computer”;

Output – o u e

Ans: -

class Overload

{

public void check(String str, char ch)

{

int result = 0;

for (int i = 0; i < str.length(); i++)

{

char currentChar = str.charAt(i);

if (ch == currentChar)

result++;

}

System.out.println("number of s present is = " + result);

}

public void check(String s1)

{

s1 = s1.toLowerCase();

for (int i = 0; i < s1.length(); i++)

{

char currentChar = s1.charAt(i);

if (currentChar == 'a' || currentChar == 'e' || currentChar == 'i' || currentChar == 'o' || currentChar == 'u')

System.out.print(currentChar + " " );

}

Question 9:

Write a program to input forty words in an array. Arrange these words in descending order of alphabets, using selection sort technique. Print the sorted array. [15]

Ans: -

import java.util.*;

class SelectionSort

{

public static void main()

{

Scanner sc = new Scanner(System.in);

String[] words = new String[40];

System.out.println("Enter 40 words: ");

for (int i = 0; i < 40; i++)

words[i] = sc.nextLine();

for (int i = 0; i < words.length - 1; i++)

{

int largestWordIndex = i;

for (int j = i + 1; j < words.length; j++)

{

if (words[j].compareTo(words[largestWordIndex]) > 0)

largestWordIndex = j;

}

String temp = words[largestWordIndex];

words[largestWordIndex] = words[i];

words[i] = temp;

}

for (int i = 0; i < 40; i++)

System.out.println(words[i]);

}

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