2nd puc computer science model 1 question papers with answers

2nd puc computer science model question papers with answers,2nd puc computer science solved model question papers

PU-II COMPUTER SCIENCE

SOLVED MODEL QUESTION PAPER 1

Answer ALL the questions.
Each question carries 1 mark. (10 X 1 = 10)

     1. Expand PCI.

Ans: Periphercal Compenent Interconnect

     2. Draw OR gate.

Ans: 

 

     

    

      3. What is data structure?

Ans: a data structure is a specialized format for organizing and storing data.

     4. Name any two member access specifiers.

Ans: private, public, protected.

     5. Define pointer.

Ans: pointer is a special variable that holds the address of another variable.

     6. What is database?

Ans: a data base is a collection of logically related data organized in a way that data can be easily accessed, managed and updated.

     7. Define network.

Ans: a network is an inter-connection of autonomous computers.

     8. What is interspace?

Ans: it is a client/server software program that allows multiple users to communicate online with real-time audio, video and text chat in dynamic 3D environments.

     9. Define telnet.

Ans: telnet is an older internet utility that allows you to log on to remote computer systems. It is used to connect thousands of catalogs at libraries around the world.

     10. Name the tag used for creating link in HTML.

Ans: anchor tag, <a href=”path”>text here</a>

Answer any FIVE of the following.
Each question carries 2 marks. (5 X 2 = 10)

      11. What is minterm and max term?

Ans: : “The sum of all the literals with or without bar in the logic system is called minterms”.

“The product of all the literals with or without bar in the logic system is called maxterms”.

      12. Prove X + YZ = (X+Y)(X+Z).

Ans: RHS=(X+Y)(X+Z)

 =XX+XZ+YX+YZ     | distributive law

         =X+XZ+XY+YZ     | indempotence law

         =X(1+Z+Y)+YZ     | properties of 0 and 1

         =X.1+YZ

         =X+YZ

         =LHS

      13. What is polymorphism?

Ans:it is an ability of the message to process in more than one form.

      14. Write disadvantages of default constructor.

Ans: - when many objects of the same class are created, all objects are initialized to same set of values by default constructor.

-          It is not possible to initialize different objects with different initial values using default constructor.

      15. Name the methods to open a file.

Ans: - opening file using constructor.

-          Opening file using open() member function.

      16. List the names of RDBMS software.

Ans: oracle, cybase, ingres, Informix,db2,ms access MySQL etc.

      17. Write the syntax of SELECT with an example.

Ans: syntax: select column1,column2…column from table name [where condition];

Example: select rollno,name from student;

      18. List any two networking goals.

Ans: - resource sharing

-          Reliability

-          Cost factor

-          Communication medium

Answer any FIVE of the following.
Each question carries 3 marks. (5 X 3 = 15)

      19. Explain the characteristics of mother board.

Ans: following are the characteristics of the motherboard,
- Form factor: it refers to the motherboard’s geometry, dimensions, arrangement and electrical requirements. Advanced Technology Extended (ATX) is the most common design of motherboard for desktop computers
- Chipset: this controls most of the computer resources. It coordinates data transfer between the various components.
- The processor socket: it may be rectangular connector into which the processor is mounted vertically, or a square shaped connector with many small connectors into which the processor is directly inserted

      20. How to covert NAND-to-AND logic.
      Ans:

      

   
      21. Explain memory representation of one-dimensional array.

Ans: elements of linear array are stored in consecutive memory locations. Let P be the location of the element. Address of first element of linear array A is given by base (A) called base address of A. using this we can calculate the address of any element of A by the formula
LOC (A [P]) =base (A) +W (P-LB)
Where W is the number of words per memory cell
Example: suppose if a string S is used to store a string ABCDE in it with starting address at 1000, one can find the address of fourth element as follows

Now the address of element S[3] can be calculated as follows:

Address(S[3])=Base(S)+W(P-LB) where W=1 for characters

                  =1000+1(3-0)

                  =1003

       22. Explain array of pointers.

Ans: An array of pointers means that it is a collection of addresses.
Example: int *iptr[5];

int i=10,j=20,k=30,l=40,m=50;

iptr[0]=&i;       *iptr[0]=10;

iptr[0]=&j;       *iptr[0]=20;

iptr[0]=&k;      *iptr[0]=30;

iptr[0]=&l;       *iptr[0]=40;

iptr[0]=&m;     *iptr[0]=50;

     23. Differentiate between text file and binary file.

Ans: 1. Binary form: - The information stored is in the form of Bits
- No delimiters are used for a line
- No translation required
2.      Text form: - The information stored is in the form of ASCII characters
- Each line of text is terminated with a special character known as EOL (End Of Line) character.
- Internal translation occurs

24. List the applications of database. 
Ans: Following are the list of database applications
- Banking: used in banks for customer, accounts, loans and banking transaction information
- Water meter billing: meter number and all the details of the customer is stored in the database
- Rail and airlines: for reservations and schedule information
- Colleges: used to store students information, course registrations and grades
- Human resources: used to store information about employees, salaries, payroll taxes and benefits etc.

25. What is proprietary software? Mention its limitations. 
Ans: proprietary software is software that is neither open nor freely available. Its use is regulated and further distribution and modification is either forbidden or requires special permission by the supplier or vendor. Source code of proprietary software in normally not available.

26. Explain the structure of HTML. 
Ans: <HTML> marks the beginning of HTML
<HEAD> begins the heading section
<TITLE>…</TITLE> gives title to the HTML document that appears on the title bar of the browser window. The text must appear between <HEAD>…</HEAD> tags; should be straight text, no other tags are to be used
</HEAD> defines the end of the heading
<BODY> defines the body of an HTML document; text written within the <BODY>…</BODY> tags appear on the canvas of the window
</BODY>
</HTML> defines the end of HTML document

Answer any SEVEN of the following. Each carries 5 marks           (7 X 5 = 35)

27. Using K-map, simplify the following expressions in four variables W,X,Y and Z.

      m₁,m₃,m₅,m₆,m₇,m₉,m₁₁,m₁₃.

Ans:

28. Write an algorithm to demonstrate binary search. 
Ans: Step 1: set B=LB, E=UB LOC=-1

   Step 2: while(B<=E)

               M=(B+E)/2

               If(ELE=A[M])

               LOC=M

               goto step 4

               else

               if(ELE<A[M])

               E=M-1

               else

               B=M+1

               end of while

   Step 3: if(LOC>=0)

                        PRINT LOC

              else

                        PRINT “Search is unsuccessful”

    Step 4: exit.

29. Demonstrate an algorithm to insert an element in a stack. 
Ans: An algorithm for PUSH() Operation
Step 1: if TOP=N then
            PRINT “stack is full”
            Exit
            End of if
Step 2: TOP=TOP+1
Step 3: STACK[TOP]=ITEM

30. Describe the advantages of OOP over earlier programming methods. 
Ans: Following are the advantages of OOP over earlier programming methods
- Using class and objects, programs are modularized
- Linking code and object allows related objects to share common code. This reduces code duplication and code reusability
- As the data is encapsulated along with functions, the non-member functions cannot access or modify data. Thus, providing data security
- Complexity of the program development is reduced through the use of inheritance
- Reduces time, as creation and implementation of OOP code is easy
- Through message passing OOP communicates to the outside system

31. Write the difference between procedural programming and object oriented programming. 
Ans:

procedural programming	object oriented programming
Variables	Objects
User defined data types	Classes
Structure members	Instance variables
Functions	Methods
Function class	Message passing

32. Define function overloading. Explain the need for function overloading. 
Ans: function overloading means two or more functions have same name, but differ in the number of arguments or data type of arguments. Therefore, it is said that function name is overloaded. The need for function overloading:
- When functions are overloaded, then the compiler automatically decides and executes appropriate function based on type of arguments and calls the required function. Thus the code is executed faster
- It is easier to understand the flow of information and debug
- Code maintenance is easy
- Easier interface between programs and real world objects

33. Write the rules for declaring constructor. 
Ans: Rules for writing a constructor function are as follows
- A constructor name is always same as that of the class name.
- There is no return type for the constructors not even void.
- A constructor should be declared in public section.
- A constructor is invoked automatically when objects are created.
- It is not possible to refer to the address of constructors.
- The constructors make implicit calls to the operators new and delete when memory allocation is required.

34. List the advantages of inheritance. 
Ans: inheritance has the following advantages
- Reusing existing code
- Faster development time
- Easy to maintain
- Easy to extend
- Memory utilization

35. Explain data processing cycle. 
Ans: the information processing cycle consists of five specific steps
- Input: any kind of data- letters, numbers, symbols, shapes, images or whatever raw material put into the computer system that needs processing. Input data is put into the computer using a keyboard, mouse or other devices such as the scanner, microphone and the digital camera. In general data must be converted to computer understandable form

- Processing: the processing is a series of actions or operations from the input data to generate outputs. Some of the operations are classification based on some condition, calculation, sorting, indexing, accessing data, extracting part of file/attribute, substring etc. conversion of data into information by the central processing unit. For example, when the computer adds 4+2=6 that is an act of processing

- Storage: data and information not currently being used must be stored so it can be accessed later. There are two types of storage, primary and secondary storage. Primary storage is the computer circuitry that temporarily holds data waiting to be processed (RAM) and it is inside the computer, secondary storage is where data is held permanently. A floppy disk, hard disk or CD. ROM is example of this kind of storage

- Output: the result or information obtained after processing the data must be presented to the user in user understandable form. The result may in the form of reports (hard copy or soft copy). Some of the output can be animated with sound and video/picture

- Communication: With wired and wireless communication connections, data may be input from a far , processed in a remote area and stored in several different places and then be transmitted by modem as an e-mail or posted to the website where the online services are rendered

36. Describe any five group functions with an example.

Ans: i) count(): this function returns the number of rows that satisfies a condition written in WHERE clause.

Ex: a) select count(*) from employee;

b)   select count(*) from employee where dept=’computer science’;

i)     max(): this function returns the maximum value from the column.

Ex: select max(salary) from employee;

ii)      min(): this function returns the minimum value from the column.

Ex: select min(salary) from employee;

iii) avg():  this function returns the average value of a numeric column.

Ex: select avg(salary) from employee;

iv) sum(): this function returns the sum of a numeric column.

Ex: select sum(salary) from employee;

37. Explain OSI reference model.

Ans:

- The physical layer: it is concern with transmitting raw bits over a communication channel.

It also deals with mechanical, electrical and timing interfaces

- The data link layer: it transform a raw transmission into a line that forms frame

- The network layer: it determines how packets are routed from source to destination

- The transport layer: it splits up packets into smaller units if needed, and pass these to the network layer and ensure that the pieces all arrive  correctly at the other end

- The session layer: it allows users on different machines to establish sessions between them. It includes dialog control, token management and synchronization

- The presentation layer: it is concerned with the syntax and semantics of the information transmitted

- The application layer: it contains a variety of protocols that are commonly needed by the user. For example, HTTP (HyperText Transfer Protocol) which is the bases for the World Wide Web (WWW) to access web pages.