
	Trending ▼ ICSE CBSE 10th ISC CBSE 12th CTET GATE UGC NET Vestibulares ResFinder

ISC Class XII Sample / Model Paper 2026 : Computer Science : Pre Board Exam

14 pages, 62 questions, 0 questions with responses, 0 total responses,

	Ancy George	+Fave Message
	Profile Timeline Uploads

Home > ancyangamaly >

Formatting page ...

COMPUTER SCIENCE PAPER 1 (THEORY) Maximum Marks: 70 Time Allowed: Three Hours (Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.) 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 The intended marks for questions or parts of questions are given in brackets [ ]. PART I 20 MARKS Answer all questions. While answering questions in this Part, indicate briefly your working and reasoning, wherever required. Question 1 (i) (ii) The compliment of the Boolean expression A (B C + B C) (a) A (B+C+B +C) (b) A+ (B+C ) (B+C ) (c) A+(B +C) (B+C ) (d) A (B +C +B C) Given below are two statements marked Assertion and Reason. Read the two statements carefully and choose the correct option. Assertion: Recursion utilises more memory as compared to iteration. Reason: Time complexity of recursion is higher due to the overhead of maintaining the function call stack. (a) Both Assertion and Reason are true, and Reason is the correct explanation for Assertion. (b) Both Assertion and Reason are true, but Reason is not the correct explanation for Assertion. (c) Assertion is true and Reason is false. (d) Assertion is false and Reason is true. 1 [1] [1] 2 (iii) According to the Principle of duality, the Boolean equation (A + B) (1 + B) = A + B will be equivalent to: [1] (a) (A + B ) (0 + B) = A + B (b) (A B) + (0 B) = A B (c) (A B) + (0 B) = A + B (d) (A + B) (0 + B) = A + B (iv) In single inheritance, which one of the following keywords should NOT be used. (a) extends [1] (b) this (c) super (d) implements (v) __________ is called a Self-Referential Data structure. (a) Stack [1] (b) Circular queue (c) Linked List (d) Double ended queue - dequeue (vi) Assertion (A): The truth table for the XOR gate shows that the output is HIGH only when an odd number of inputs are HIGH. [1] Reason (R): The XOR gate performs addition modulo 2, thus producing a HIGH output when the number of HIGH inputs is odd. (a) Both Assertion and Reason are true, and Reason is the correct explanation for Assertion. (b) (c) (d) (vii) Both Assertion and Reason are true, but Reason is not the correct explanation for Assertion. Assertion is true and Reason is false. Assertion is false and Reason is true. The java statement to print the position of 2nd occurrence of the letter 'I' within the word "IMPLICIT". (viii) A full adder needs five gates and those are 3 AND gates, 1 OR gate and 1 XOR gate. When a full adder is constructed using 2 half adders, it also requires 5 gates. (ix) (x) State the names along with the quantity those gates. [1] [1] For Big O notation, state the difference between O(n) and O(n2). [1] Consider the following statement written in class Circle where pi is its data [1] 3 member. static final double pi = 3.142; Which of the following statements are valid for pi? I. It contains a common value for all objects class Circle. II. Its value is non-changeable. III. At a time two access modifiers, static and final, cannot be applied to a single data member pi. (a) I and II (b) II and III (c) I and III (d) Only III Question 2 (i) Convert the following infix notation to prefix form. (A B)/C*(D+E)+F (ii) A matrix M[-6 .10, 4 15] is stored in the memory with each element requiring 4 bytes of storage. If the base address is 2050, find the address of M[4][6] when the matrix is stored in column major wise. (iii) The following function getIt() is a part of some class. Assume x is a positive [2] [2] integer, f is the lower bound of arr[ ] and l is the upper bound of the arr[ ]. Answer the questions given below along with dry run/working. public int getIt(int x,intarr[],int f,int l){ if(f>l) return -1; int m=(f+l)/2; if(arr[m]<x) return getIt(x,m+1,l); else if(arr[m]>x) return getIt(x,f,m-1); else } return m; (a) What will the function getIt( ) return if arr[ ] = {30,40,50,60,70} and x=60? [2] (b) What is function getIt( ) performing apart from recursion? [1] 4 (iv) The following is a function of class Armstrong. This recursive function calculates and returns the sum of the cubes of all the digits of num, where num is an integer data member of the class Armstrong. [A number is said to be Armstrong if the sum of the cubes of all its digits is equal to the original number]. There are some places in the code marked by ?1?, ?2?,?3? which may be replaced by a statement/expression so, that the function works properly. public int sumOfPowers(int num) { if (num == 0) return ?1?; int digit = ?2?; return (int) Math.pow(digit, 3) + ?3?; } } (a) What is the expression or statement at ?1? (b) What is the expression or statement at ?2? (c) What is the expression or statement at ?3? 5 [1] [1] [1] [1] [1] PART II 50 MARKS 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 3 A shopping mall announces a special discount on all its products as a festival offer only to those who satisfy any one of the following conditions. If he/she is an employee of the mall and has a service of more than 10 years. OR A regular customer of the mall whose age is less than 65 years and should not be an employee of the mall. OR If he/she is a senior citizen but not a regular customer of the mall.. The inputs are: INPUTS E Employee of the mall R Regular customer of the mall S Service of the employee is more than 10 years C Senior citizen of 65 years or above (In all the above cases, 1 indicates yes and 0 indicates no.) Output: X - Denotes allowed to travel [1 indicates yes and 0 indicatesno in all cases] (i) Draw the truth table for the inputs and outputs given above and write the (ii) Draw the logic diagram for the reduced SOP expression X ( E, R, S, C ). SOP expression for X ( E, R, S, C ) [5] You may use gates with two or more inputs, assume the variables and their complements are available as inputs. 6 [5] Question 4 (i) (a) Reduce the Boolean function F(P,Q,R,S) = (P+Q+R+S) (P+Q+R+S ) (P+Q+R +S) (P+Q +R+S) (P+Q +R+S ) (P+Q +R +S) (P+Q +R +S ) [4] (P +Q+R+S) (P +Q+R+S ) by using 4-variable Karnaugh map, showing the (b) (ii) (a) various groups (i.e. octal, quads and pairs). Draw the logic gate diagram for the reduced expression. Assume that the variables and their complements are available as inputs. [1] [4] From the given logic diagram : (b) Derive Boolean expression and draw the truth table for the derived expression. (Application) (b) If A=1, B=0 and C=1 then find the value of X. Question 5 [1] [1] (i) Draw the logic circuit to decode the following binary number (0001, 0101, 0111, 1000, 1010, 1100, 1110,1111) to its hexadecimal equivalents. Also state the Hexadecimal equivalents of the given binary numbers. [5] (ii) Verify if the following proposition is valid using the truth table: (X Y) =>Z = (Y =>Z) (X =>Y) [3] (iii) Answer the following questions related to the below image (a) (b) What is the output of the above gate if input A=0, B=1? (Analysis) [1] What are the values of the inputs if output =1? 7 [2] 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 6 An Automorphic number is a number whose square ends with the given number itself. E.g. (5)2 = 25, (25)2 = 625, (76)2 = 5776. Design a class Automorphic to check if numbers in the given range are Automorphic numbers or not. The member functions and data members of the class are given below: Class Name : Automorphic : lower and upper limits of the range Data members/instance variables: l, u count : Member functions : frequency of the automorphic numbers in the range l and u Automorphic(int l, int u) : parameterised constructor to assign values to data boolean check(int n) : to check if n is an automorphic number. If yes it returns void list( ) : to check all the numbers between the range l and u, by members true otherwise returns false. calling check(int n) and to display only the automorphic numbers. Also to display the frequency of the automorphic numbers in the given range. Specify the class Automorphic giving details of the parameterised constructor, boolean check(int n) and void list( ). Create one object in the main( )method and call all the methods appropriately. Sample input Enter the lower limit of the range->1 Enter the upper limit of the range->1000 Sample output List of Automorphic numbers from 1 to 1000 : 8 Number Square 11 5 25 6 36 25 625 76 5776 376 141376 625 390625 Frequency of Automorphic numbers between 1 to 1000 : 7 Question 7 A class Mixarray contains an array of integer elements along with its capacity (More than or equal to 3). Using the following description, form a new array of integers which will contain only the first 3 elements of the two different arrays one after another. Example: Array1: { 78, 90, 100, 45, 67 } [10] Array2: {10, 67, 200, 90 } Resultant Array: { 78, 90, 100, 10, 67, 200} The details of the members of the class are given below: Class name : arr[] : Mixarray Data members/instance variables: cap : integer array integer to store the capacity of the array Member functions/methods: Mixarray (int mm ) void input( ) : to initialize the capacity of the array cap=mm : to accept the elements of the array Mixarray mix(Mixarray P, Mixarray Q) : returns the resultant array having the first 3 elements of the array of objects P and Q void display( ) : to display the array with an appropriate message. Specify the class Mixarraygiving details of the constructor(int), void input( ), 9 Mixarray mix(Mixarray,Mixarray) and void display( ). Define a main( ) function to create objects and call all the functions accordingly to enable the task. Question 8 Design a class Spy to check if a number is a Spy number or not. A spy number is a number where the sum of its digits equals the product of its digits. For example, 1124 is a spy number, the sum of its digits is 1+1+2+4=8 and the product of its digits is 1*1*2*4=8. Class name Data Members: num Member methods: Spy(int nn) : Spy : to store the number : initialize the data member num=nn int sumOfDigits(int i) : returns the sum of digits of num using recursive technique int prodOfDigits( int i) : returns the product of digits of num using recursive void check( ) technique : checks whether the given number is a Spy number or not by invoking the functions sumOfDigits( ) and prodOfDigits( ) and displays appropriate message Specify the class Spy giving details of the functions int sumOfDigits(int ), void check( ), int prodOfDigits(int). Assume that the data member and constructor are already defined. Define a main method to create an object and call the functions accordingly to enable the task. 10 SECTION C Answer any two questions. Each program should be written in such a way that it clearly depicts the logic of the problem stepwise. This can be achieved by using comments in the program and mnemonic names or pseudo codes for algorithms. The programs must be written in Java and the algorithms must be written in general / standard form, wherever required / specified. (Flowcharts are not required.) Question 9 Recycle is an entity which can hold at the most 100 integers. The chain enables the user to add and remove integers from both the ends i.e. front and rear. Define a class ReCycle with the following details: Class name : ReCycle Data members/instance variables: ele[ ] : the array to hold the integer elements cap : stores the maximum capacity of the array front : to point the index of the front rear : to point the index of the rear Methods / Member functions: ReCycle (int max) : constructor to initialize the data cap = max, front = rear = 0 and to create the integer array. void pushfront(int v) : to add integers from the front index if possible else display the message( full from front ). int popfront( ) : to remove the return elements from front. If array is empty then return-999. void pushrear(int v) : to add integers from the front index if possible else display the message( full from rear ). int poprear( ) : to remove and return elements from rear. If the array is empty then return-999. Specify the class ReCycle giving details of the functions void pushfront(int) and int poprear( ). Assume that the other functions have been defined. (a) The main( ) function and algorithm need NOT be written. (b) Name the entity described above and state its principle. 11 Question 10 [5] A library issues books on rental basis at a 2% charge on the cost price of the book per day. As per the rules of the library, a book can be retained for 7 days without any fine. If the book is returned after 7 days, a fine will also be charged for the excess days as per the chart given below: Number of excess days 1 to 5 Fine per day (Rs.) 6 to 10 Above 10 2.00 3.00 5.00 A super class Library has been defined. Define a sub class Compute to calculate the fine and the total amount. The details of the members of both the classes are given below: : Library name : to store the name of the book author : to store the author of the book Class name Data members/instance variables: p Methods / Member functions: : to store the price of the book (in decimals) Library( ... ) : parameterized constructor to assign values to the void show( ) : displays the book details Class name data members Compute Data members/instance variables: d : number of days taken in returning the book f : to store the fine (in decimals) Compute( ... ) : parameterized constructor to assign values to the data members of both the classes void fine( ) : calculates the fine for the excess days as given in void show( ) : displays the book details along with the number Methods / Member functions: the table above of days, fine and the total amount to be paid. Total amount is (2% of price of book * total no of days) + fine 12 Assume that the super class Library has been defined. Using the concept of inheritance, specify the class Compute giving the details of the constructor(...), void fine( ) and void show( ). The super class, main function and algorithm need NOT be written. Question 11 (i) With the help of an example, briefly explain the constant factor in time complexity. (ii) Answer the following questions from the diagram of a Binary Tree given below: [2] (a) Name the internal nodes of the right sub tree. [1] (b) State the size and depth of the tree. [1] (c) Write the in-order traversal of the above tree structure. [1] 13 14

Formatting page ...

ancyangamaly chat

Horizontal lines at:
Guest Horizontal lines at:
AutoRM Data:
Box geometries: