#### This is a practice paper for class XII students. It covers almost all topics of class xii syllabus.

**For String programs click**

**https://java4school.com/string-programs-part-5**

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*Answer **all** questions in Part I (compulsory) and **four** questions from Part-II, choosing **two** questions from Section-A, **two** from Section-B *

*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**

*Answer **all** questions*

**Q 1. [5X1=5]**

- What is Tautology and contradiction in Boolean algebra?
- Name a Character function used to check if a character is an alphabet or digit
- State the Principle of Duality.
- Write the contra positive statement for the following conditional statement: If I see lightning then it is raining. .
- Draw the logic circuit of a NAND gate using NOR gates only.

Q 2. **[5X2=10]**

- What is coercion? Explain with example.
- Each element of an array ARR[-5… 2,-2 … 5] requires 1 byte of storage. If the array is stored in column major order beginning location 3500, find the location of ARR[0,0].
- Convert the following infix expression into postfix.

(A-B)/C +(E%F) /M - Given F(A, B, C)=AB+BC’ to its canonical SOP form.
- Show that the dual of A’BC’+AB’C+A’B’C is equal to the complement of AB’C+B. (A’C’+AC’)

Q 3. Given the following code. Show the dry run/ working. int fun(int a, int b)

{

if (b == 0)

return 0;

if (b % 2 == 0)

return fun(a+a, b/2);

return fun(a+a, b/2) + a;

}

What will be the output for the call fun(3,2)? [2]

What will be the output for the call fun(4,3) ? [2]

What is the function fun() doing? [1]

**Part II**

Answer six questions in this part, choosing two questions from Section A, two from Section B **Section A**

Answer any two questions

**Q 4. **Given the Boolean function: F (X,Y,Z,W) = Σ (0, 2, 4, 8, 9, 10,12,13)

- Reduce the above expression by using 4 – variable K-Map, showing the various groups. [4]
- Draw the Logic gate diagram of the reduced expression. Assume that the variable and their complements are available as inputs. [1]

**Q 5. **Given F(A,B,C,D)= (A+B+C+D).(A+B+C+D’).(A+B+C’+D’). (A+B+C’+D). (A+B’+C+D’). (A+B’+C’+D’).(A’+B+C+D).(A’+B+C’+ D)

- Reduce the above expression by using 4- variable K-Map, showing the various groups (i.e. octets, quads and pairs). [4]
- Draw the logic gate diagram of the reduced expression. [1]

**Q 6. **What is a Multiplexer? Draw the truth table and logic diagram of an 8:1 multiplexer. **[5]**

**Section B****Answer both 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. [2X5=10]**

**Q 7.**

A class Rearrange has been defined to insert an element and to delete an element from an array. The data members are

Arr[] : integer type array

N : size of array (integer)

**Member Functions/ Methods**

Rearrange( ) : Default Constructor to initialize the data members

void enter() : to enter size N followed by array elements to store in array Arr. void insert(int p, int item): to insert an item at the position p of the array Arr.

void display() : to display array elements.

void remove(int p) :to delete an element at the position p of the array Arr.

Specify the class Rearrange giving details of the constructor and other member functions. The main() function need not be written.

**Q 8.** Link is an entity which can hold a maximum of 100 integers. Link enables to add elements from the rear end and remove integers from the front end of the entity. Define a class Link with the following details:

**Class name Link** **Data members**

lnk[] : entity to hold the integer elements.

max : stores the maximum capacity of the entity.

begin : to point to the index of the front end.

end: to point to the index of the rear end.

**Member functions**

Link(int nn) : constructor to initialize max=mm, begin=0, end=0.

void addLink(int v) : to add an element from the rear index if possible otherwise display the message “OUT OF SIZE”.

int dellink() : to remove and return an element from the front index, if possible otherwise display the message “EMPTY…” and return -99.

void display() : displays the elements of the entity.

Specify the class Link giving details of all the functions.

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