#### This is a ISC class XI practice test for computer students. The topics covered in this paper are Boolean Algebra, Logic gates, Number conversions

**Matrix programs**

**ISC class XI practice test****Part I (20 marks)****Q 1. **Perform the following conversions (Step by step working has to be written in the answer paper)

- (1537)
_{8}+ (2356)_{8} - (EA9C)
_{16}– (ABCD)_{16} - (110110)
_{2}-(101011)2=( )_{2} - (110011)
_{2}x (100)_{2} - (345.33)
_{8}=( )_{2} - (1440)10==( )
_{8}= ( )_{2}= ( )_{16} - (1101011.1100)
_{2}=( )_{16}=( )_{8} - (1010110)
_{2}=( )_{8}= ( )_{10} - (ADCE)
_{16}= ( )_{8}= ( )_{2} - (165.35)
_{10}=( )_{2}

**isc class xi practice test****Part II (20 marks) Section A (10 marks)****Q 2.**

- Prove the following using truth table

A.(A+B)=A - Draw truth table of (a+b+c).(a’+b’).
- Show that (p → q) ∧ (q → p) is logically equivalent to p ↔ q.
- Prove any one commutative law with truth table.
- Explain the NAND gate with logic gate diagram and truth table

**Q 3.**

- Define tautology with example.
- Write the contra positive statement of the following.

If you don’t study then you will not pass your exam.

- Prove any one absorption law with truth table.
- Explain XOR gate with truth table and logical circuit.
- Find the dual of the following. (A+B’)(A.B)+1=0

** isc class xi practice test****Section B (10 marks)** **(Attempt any one program)**

**Q4** Design a class Count to perform the given task. Some of the data members are given.

**Class name**** ****: Count**

str: to store the string

value: to store the sum of ASCII count of all the characters

**Member functions:**

Count() | : constructor to initialize member data |

void accept() | : to accept the string from the user |

int chkSum(String a, int i) | : to calculate and return the sum of the ASCII of the characters at the i th location in the string |

void display() | to display the original string, to call function chkSum() and then display the sum of the ASCII values of all the characters. |

Specify the class as instructed giving details of the constructor and the member functions. Define the main() function and call the methods accordingly to enable the task.

**Q 5**. A Special number is a number in which the sum of the factorial of its digits is equal to the number. Example 1445 ( 1! + 4! + 5!= 145). Thus, 145 is a special number. Design a class Special to check if the given number is a Special number or not. Some of the members of the class are given below:

**Class name : Special**

**Data members**

n : integer to store the number

**Member functions**

Special() : default constructor

void read() : to accept the number

int factorial(int x) : return the factorial of a number

boolean isSpecial() : checks for the special number by invoking the function factorial() and returns true if Special, otherwise returns false.

void display() : to show the result with an appropriate message

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