 ## Rotate a matrix program

Answer all questions in Part I (compulsory) and six questions from Part-II, choosing two questions from Section-A, two from Section-B and two from Section-C.All working, including rough work, should be done on the same sheet as the rest of the answer.The intended marks for questions or parts of questions are given in brackets[ ]

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PART I (20 Marks)

While answering questions in this Part, indicate briefly your working and reasoning, wherever required.

Question 1

(a)    Draw the truth table to represent a two input NAND gate.

(b)    construct the truth table for the following ~[(~A).B]

(c)    State the two idempotent laws of Boolean algebra. Verify any one.

(d)    Minimize: F = ABC+AB’C+AC’ using Boolean laws.

(e)    If A denotes “Today is sunday ” and B denotes “I will not go to school”, then express the following    statements in symbolic form:

(i)   If today is not sunday  then I will go to school

(ii)   If I go to school  then today is not sunday.

Question 2

(a)Name any two packages of java. Name the package which is imported by default.

(b)    Convert the following arithmetic expression into Java statement

x = √(M2 + N3)+ M*N

(c)    Define the term truth table.

(d)    Name the File Stream Class to perform the following operations:

(i)    to write data into a binary file

(ii)   to read data from a text file

(e)    Differentiate between constructor and function.

Question 3

The  following  function  magicfun(  ) is  a part  of some  class. What will  the function magicfun()  return when  the  value  of  n=7  and  n=10  respectively?  Show  the  dry run/working:                                                                                                                                                                                                                                                              ISC class XI sample paper 2021

int  magicfun( int n)

{

if (  n= = 0)  .

return  0;

else

return  magicfun(n/2)* 10 + (n % 2);

}

PART – II(50 Marks) ISC class xi sample paper 2021

Answer six questions in this part, choosing two questions from

Section A, two from Section B and two from Section C.

SECTION – A

Question 4 Perform the following conversions / operations:

(i)    (110011.101)2    =(?)8                            

(ii)    (521)8 = ( ? )2                                           

(iii)(101010.10)2    =(?)16                            

(iv)    (422)10=( )2                                         

(v)    1001  x  101                                

Question 5

(a)       A passenger is allotted a window seat in an aircraft, if he/she satisfies the criteria given below

·                  The passenger is below 10 years and is accompanied by an adult

OR

·                  The passenger is a lady and is not accompanied by an adult

OR

·                  The passenger is not below 10 years, but is travelling the first time

The inputs are

A: The passenger is below 10 years

C: The passenger is accompanied by an adult.

L: The passenger is a lady.

F:  the passenger is travelling for  the first time.

(in all cases 1 indicates yes and 0 indicates no)

Output: W- Denotes the passenger is allotted a window seat (1 indicates yes and 0 indicates no)

Draw the truth table for the inputs and outputs. Also, write the Boolean expression with conjunctive operators for each of the true values (1’s) from the output column of the truth table.   

(b)   Prove the following Boolean expression with the help of a truth table:    

(A+ B)’= A’. B’

(c)   What are Universal gates? Draw the AND gate using a universal gate.    

Question 6

(a)    Write the expression and draw the logic circuit for a half Adder.                                          

(b)    Verify if: (a => b) V ( b => a) = 1                                                                                        

(c)    Draw the logic circuit for the following Boolean expression:                                        

X=(P+Q’) .(P’+M).(M’+Q)

ISC class XI sample paper 2021

SECTION – B

Each program should be written in such a way that it clearly depicts the logic of the problem.

This can be achieved by using mnemonic names and comments in the program.

(Flowcharts and Algorithms are not required.)

The programs must be written in Java.

Question 7

A class Revstr defines a recursive function to reverse a string and check whether it is a palindrome. The details of the class are given below:

Class name   :  Revstr

Data members Str    :  stores the string.

Revst    :  stores the reverse of the string.

Member functions void getStr()   :  to accept the string.

void recReverse(int)  :  to reverse the string using recursive technique.

void check()   :  to display the original string, its reverse and whether  the string is a palindrome or not.

Specify the class Revstr  giving details of the functions void getStr(), void recReverse(int) and void check(). The main function need not be written.

ISC class XI sample paper 2021

Question 8                                                        

Design a class PrimePalinGen to generate prime palindrome numbers. [ A number is said

to be prime palindrome if the number is a prime as well as a palindrome number ]

[ Prime number: A number having only two factors i.e. 1 and itself ]

[ Palindrome number: A number which is same as its reverse ]

Example: 11(where 11 is a prime number and a palindrome number)

Some of the members of the class are given below:

Class name    :    PrimePalinGen

Data members/instance variables:

start    :   to store the start of range

end    :   to store the end of range

Methods/Member functions:

PrimePalinGen (int a, int b):   parameterized constructor to initialize the data members start=a and end=b

int isPrime(int i)    :   returns 1 if the number is prime otherwise    returns 0

int isPalin(int i)    :   returns  1  if  the  number  is  a  palindrome otherwise returns 0

void generate( )    :    generates  all  prime  palindrome  numbers between  start  and  end  by  invoking  the functions isPrime() and isPalin().

Specify the class PrimePalinGen giving details of the constructor( ),int isPrime(int), int isPalin(int) and void generate( ). Define a main( ) function to create an object and call the functions accordingly to enable the task.
ISC class xi sample paper 2021

Question 9

A class ArrayMin contains a square matrix which finds the smallest element in each column.    

Some of the members of the class are given below:

Class name    :   ArrayMin

Data member/instance variable:

arr[ ][ ]    :   array to store integer elements

m    :   to store the order of the matrix

Member functions/methods:

ArrayMax( int mm):   parameterized constructor to initialize the data member m=mm and to declare the array

void readarray()    :   to accept the array elements

void small( )    :   finds and displays the smallest element in each column with an appropriate message

void display()    :   displays the array elements in matrix form

Specify the class ArrayMax, giving the details of the constructor( ), void readarray( ), void large( ) and void display( ). Define the main( ) function to create an object and call the functions accordingly to enable the task.

ISC class xi sample paper 2021

SECTION – C

Each method should be written in such a way that it clearly depicts the logic of the problem stepwise.

This can be achieved by using mnemonic names and comments in the program.

(Flowcharts and Algorithms are not required.)

The methods must be written in Java.

Question 10

Write a Method to calculate and return the factorial of a number ‘n’ using recursive technique.

The method declaration is as follows:

int factorial( int n )                                                                                                          

Question 11

(a)    A text file named STUDENT.TXT” contains the student name (sn),  age(ag) and         

marks(mk) for number of students.

Write a Method to display all the records in the file and display with an appropriate message.

The method declaration is as follows:

void display( )

(b)    State any one difference between binary file and text file.                                              

Question 12

Answer the following questions given below:                                                                [5X1=5]

(i)    What is the difference between virtual and augmented reality?

(ii)    Explain phishing.

(iii) Explain IOT.

(iv)    Define cyber crime.

(v)    Write any two points to be followed by a good netizen.