ICSE Question Paper – 2012 (Solved)

ICSE Question Paper – 2012 (Solved)

Computer Applications

Class X

(Time: Two Hours)

SECTION A (40 Marks)

Answer all questions from this Section

Question 1.

(a)Give one example of a primitive data type and composite data type.                                          [2]

Ans.   Primitive type:  byte/short/int/long/float/double/char/boolean

Composite type: classes/interface/arrays

(b) Give one point of difference between unary and binary operators.                                            [2]

Ans.  Unary operators work on a single operand eg. ++a  while binary operators work on two operands eg. a+b

© Differentiate between call by value or pass by value and call by reference or pass by reference [2]

Ans. Call by value method creates a new copy of formal parameters and the changes made to them in the called function are not reflected on the actual arguments in the calling function. They work for primitive data types while call by reference method does not create a new copy rather works on the reference of actual arguments and changes made to them in the called function are reflected in the calling function. They work for reference data types.

(d) Write java expression for √2as+u²        [2]

Ans.   double  d= Math.sqrt((2*a*s + u*u));

(e) Name the type of error (syntax, runtime or logical error) in each case given below:       [2]

Ans.  (i) Division by a variable that contains a value of zero :  Runtime error

(ii) Multiplication operator used when the operation should be division : Logical error

(iii) Missing semicolon:  Syntax error

Question 2.

(a) Create a class with one integer instance variable. Initialize the variable using :

(i) Default constructor

(ii) parameterized constructor

Ans.

class Initialize

{

int x;  //instance variable

Initialize() //default constructor

{

x=0;

}

Initialize(int a) //parameterized constructor

{

x=a;

}

}

(b) Complete the code given below to create an object of Scanner class:                            [2]

Ans.     Scanner sc=new Scanner (System.in);

© What is an array? Write a statement to declare an integer array of 10 elements                           [2]

Ans.   An array is a structure created in memory to store multiple similar type of data under a single subscripted variable name.

int a[]=new int[10];

(d) Name the search or sort algorithm that :     [2]

(i) Makes several passes through the array, selecting the next smallest item in the array each time and placing it where it belongs in the array :  Selection sort

(ii) At each stage, compares the sought key value with the key value of the middle element of the array: Binary search

(e) Differentiate between public and private modifiers for members of a class       [2]

Ans. The scope of private members of a class is within the class itself whereas the the scope of the public members of a class is outside the class also ( outside the package also).

Question 3.

(a) What are the values of x and y when the following statements are executed?          [2]

int a=63, b=36;

boolean x = (a>b) ? true :  false ;

int y=(a<b) ? a : b;

Ans.

x=true

y=36

(b)  State the values of n and ch.      [2]

char c=’A’;

int n=c+1;

char ch=(char)n;

Ans.    n=66        ,      ch=B

© What will be the result stored in x after evaluating the following expression?     [2]

int x = 4;

x+= (x++)+(++x)+x;

Ans. 

x=4+4+6+6

=20

(d) Give output of the following program segment:                                                  [2]

double  x= 2.9 ,  y=2.5;

System.out.println(Math.min(Math.floor(x),y));

System.out.println(Math.max(Math.ceil(x),y));

Ans.

2.0

3.0

(e)  State the output of the following program segment:                                           [2]

String s=”Examination”;

int n=s.length();

System.out.println(s.startsWith(s.substring(5,n)));

System.out.println(s.charAt(2) == s.charAt(6));

Ans.

false

true

(f) State the method that:      [2]

(i)  Converts a string to a primitive float data type   :  parseFloat()

(ii) Determines if the specified character is an upper case character: isUpperCase()

(g)  State the data type and values of a and b after the following segment is executed:     [2]

String  s1= “Computer”,  s2=“Applications”;

a = (s1.compareTo(s2));

b = (s1.equals(s2));

Ans.  a=2  or  positive          data type :   int

b=  false          data type :    boolean

(h)  What will the following code output:       [2]

String s= “malayalam”;

System.out.println(s.indexOf(‘m’));

System.out.println(s.lastIndexOf(‘m’));

Ans.

0

8

(i) Rewrite the following program segment using while instead of for statement[2]

int f=1,I;

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

{

f*=i; System.out.println(f);}

Ans.

int f=1,  i=1;

while (i<=5)

{

f*=i

System.out.println(f);

i++;

}

(j)  In the program given below:        [2]

class MyClass{

static int x = 7;

int y = 2;

public static void main(String args[]){

MyClass obj = new MyClass();

System.out.println(x);

Obj.sampleMethod(5);

int a= 6;

System.out.println(a);

}

void sampleMethod(int n){

System.out.println(n);

System.out.println(y);

}

}

State the name and value of the :

(i) method argument or argument variable:      5

(ii)  class variable  :   x

(iii)  local  variable:    a

(iv)  instance variable :  y

SECTION B(60 Marks)

Answer any four questions

Also write the variable description/pneumonic codes

Question 4.

Define a class called Library with the following description:

Instance variables/data members:

Int acc_num         : stores the accession number of books

String title            : stores the title of book

String author        :  stores the name of author

Member methods:

Void input() :  to input and store the accession number, title and author

Void compute():  to accept the number of days late, calculate and display the fine charged t the rate of Rs. 2 per day

Void display():   to display the details in the following format:

Accession number             Title         Author

Write the main method to create an object of the class and call  the above member methods                    [15]

Ans

import java.util.*;

class Library  {

int  acc_num;

String title, author;

void input {

Scanner sn=new Scanner(System.in);

System.out.println(“enter the accession number, title and author”);

acc_num= sn.nextInt();

title= sn.nextLine();

author = sn.nextLine();

}

void compute() {

Scanner sn=new Scanner(System.in));

System.out.println(“enter the number of days late”);

int n= sn.nextInt();

int fine=n*2;

System.out.println(“fine :  “+fine);

}

void display()  {

System.out.println(“Accession Number \t\t Title \t\t Authpr”);

System.out.println(“acc_num+”\t\t”+title+”\t\t”+ author);

}

public static void main() throws IOException

{

Library ob=new Library();

ob.input();

ob. compute();

ob.display();

}

}

Question 5.

Given below is a hypothetical table showing rates of income tax for male citizens below the age of 65 yrs:

Does not exceed Rs. 1,60,000        -nil

TI > Rs. 1,60,000 & <=Rs. 50,000   –

(TI- 1,60,000)*10%

 TI >Rs.5,00,000  & <=Rs. 8,00,000  -  [(TI-5,00,000)*20%]+34,000

TI >Rs. 8,00,000 – [(TI-8,00,000)*30%]+94,000

Write a program to input the age, gender(male or female) and taxable income(TI) of a person.

If the age is more than 65 yrs or the gender is female, display “wrong category”.

If the age is less than or equal to 65 yrs and the gender is male, compute and display the income tax payable as  per the table given above.        [15]

Ans.

import java.util.*;

class IncomeTax {

public static void main(){

Scanner sn=new Scanner(System.in);

System.out.println(“enter age,  gender and taxable income”);

int age=sn.nextInt();

String gender= sn.next();

int TI=  sn.nextInt();

double tax=0.0;

if((age>65) || (gender.equals(“female”)))

System.out.println(“wrong category”);

else if((age<=65) && (gender.equals(“male”)))

{

if(TI<160000)

tax=0;

else if(TI>160000 && ti<=500000)

tax=(TI-160000)*(double)10/100*TI;

else if(TI>500000 && TI<=800000)

tax=(TI-500000)*((double)20/100*TI)+34000;

else

tax=(TI-800000)*((double)30/100*TI)+94000;

}

else

System.out.println(“wrong category”);

}//main  ends

} //class ends

Question 6.

Write a program to accept a string. Convert it to uppercase. Count and output the number of double letter sentences that exist in the string.    [15]

Sample Input: “SHE WAS FEEDING THE LITTLE RABBIT WITH AN APPLE”

Sample Output:   4

Ans.

class DoubleLetter  {

void count(String s1) {

s=s1.toUpperCase();

int l=s.length();

int c=0;

for( int p=0; p<l-1;  p++)

{

if(s.charAt(p) == s.charAt(p+1))

c++;

}//for ends

System.out.println( c  );

}//method ends

}//class ends

Question 7.

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

(i) void polygon(int n, char ch)  :   with one integer argument and one character type argument that draws a filled square of side n using the character stored in ch.

(ii) void polygon(int x, int y) :  with two integer arguments that draws a filled rectangle of length x and breadth y, using the symbol ‘@’

(iii) void polygon() :  with no argument that draws a filled triangle shown below:

*

* *

* * *

Ans.

class Overload  {

void polygon(int n , char ch)   {

for (int  p= 1;  p<=n;  p++)

{

for(int q=1; q<=n; q++)

System.out.print(ch);

System.out.println();

}

}//method ends

void  polygon(int x, int y)  {

for(int p = 1;   p<=x;  p++)

{

for ( int q=1;  q<=y; q++)

System.out.print(“@”);

System.out.println();

}

}//method ends

void polygon()  {

for(int p= 1; p<=3; p++)

{

for( int q=1; q<=p; q++)

System.out.print(“*”);

System.out.println();

}

}//method ends

}//class ends

Question 8.

Using the switch statement, write a menu-driven program to:

(i) Generate and display the first 10 terms of the Fibonacci series 0,1,1,2,3,5,….

(ii) find the sum of the digits of an integer that is input. Eg 15390=18

For an incorrect choice, appropriate error message should be displayed.  [15]

Ans.

import java.io.*;

class Menudriven    {

public static void main()

{

Scanner sn=new Scanner(System.in);

System.out.print(“Enter 1 for Fibonacci numbers/ 2 for sum of digits”);

int ch=sn.next();

switch( ch)

{

case 1:

int a=0, b=1, c;

System.out.print(a+  “    “+ b);

for(int p=3; p<=10; p++)

{

c=a+b;

System.out.print(“   “+c);

a=b;

b=c;

}//for ends

break;

case 2:

System.out.println”\nenter an integer”);

int n = sn.nextInt();

int quo=0,rem=0, sum=0;

while(quo!=0)

{

rem%=10;

quo/=10;

sum+=rem;

}//while ends

System.out.println(“\nsum of digits  “+sum);

break;

default:

System.out.println(“ Incorrect choice. Enter 1 or 2 only”);

}//switch ends

}//main ends

}//class ends

Question 9.

Write a program to accept the names of 10 cities in a single dimension string array and their STD codes in another single dimension integer array. Search for a name of a city input by the user in the list. If found, display “search successful” and print the name of the city along with its STD code, or else display the message” search unsuccessful, no such city in the list”.    [15]

Ans.

import java.io.*;

class LinearSearch {

 public static void main()

{

Scanner sn=new Scanner(System.in);

String city[]  =new String[10];

int std[]=new int[10];

for(int i=0;i<10;i++)

{

System.out.println(“enter city and std code”);

city[i]=sn.next();

std[i]=sn.nextInt();

}

System.out.print(“Enter the city to be searched”);

String ele = sn.next();

int c=0;

for(int p=0;  p<10; p++)

{

if(city[p] . equals(ele))

{

c=1;

break;

} //end if

}//end for

if(c==1)

{

System.out.print(“Search Successful”);

System.out.print(“City:   “+city[p]+”\tSTD  :”+std[p]);

}

else

System.out.print(“Search Unsuccessful. No such city in the list”);

}//end method

}//end class