ISC class XI sample paper 2021
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)
Answer all questions.
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
Answer any two questions.
Question 4 Perform the following conversions / operations:
(i) (110011.101)2 =(?)8 [2]
(ii) (521)8 = ( ? )2 [2]
(iii)(101010.10)2 =(?)16 [2]
(iv) (422)10=( )2 [2]
(v) 1001 x 101 [2]
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. [5]
(b) Prove the following Boolean expression with the help of a truth table: [3]
(A+ B)’= A’. B’
(c) What are Universal gates? Draw the AND gate using a universal gate. [2]
Question 6
(a) Write the expression and draw the logic circuit for a half Adder. [5]
(b) Verify if: (a => b) V ( b => a) = 1 [3]
(c) Draw the logic circuit for the following Boolean expression: [2]
X=(P+Q’) .(P’+M).(M’+Q)
ISC class XI sample paper 2021
SECTION – B
Answer any two questions.
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 [10]
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. [10]
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
Answer any two questions.
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 ) [5]
Question 11
(a) A text file named STUDENT.TXT” contains the student name (sn), age(ag) and [4]
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. [1]
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.
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