# 2nd PUC Computer Science Previous Year Question Paper March 2015

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## Karnataka 2nd PUC Computer Science Previous Year Question Paper March 2015

Time: 3 Hrs 15 Min
Max. Marks: 100

PART – A

Answer all the following questions. Each question carries one mark. (10 × 1 = 10)

Question 1.
What is data bus?
A set of wire connected between the control unit and other units like memory, Input/Output device.

Question 2.
Which basic gate is also called as inverter?
The NOT gate is named as Inverter.

Question 3.
What is meant by primitive data structure?
The data structures that are directly operated upon by machine-level instructions are called as primitive data structure.

Question 4.
What is a member function?
The member functions are behaviour of a class and can access or manipulate data members without passing them as parameters.

Question 5.
Write the declaration syntax for a pointer.
Syntax:
data-type * pointer-variable-name;

Question 6.
Define primary key.
Primary key uniquely identifies each record in a database.

Question 7.
Expand FTP.
File Transfer Protocol

Question 8.
What is network topology?
It is the geometric arrangement of computer system in network. Common topologies include a Linear bus, star, ring and ring.

Question 9.
What is freeware?
A software available free of cost to use and distribute, but not for modification and without source code.

Question 10.
Mention the use of HTML.
The HTML is used to create web pages.

PART – B

Answer any five questions. Each question carries two marks. (5 × 2 = 10)

Question 11.
Prove that x + xy = x
Prove that X + XY = X.

Question 12.
Define minterm and maxterm.
A minterm is a special product of literals, in which each input variable appears exactly once. A. maxterm is a sum of literals, in which each input variable appears exactly once.

Question 13.
Briefly discuss the classes in OOP.
The Class allow to group functions and data variables. The class is a way to grouping objects having similar characteristics. The objects can be made user defined data type with the help of a class.

Question 14.
What is a destructor? Write its syntax.
It is a special function used to release the memory space allocated by the object.
General Syntax of Destructors

~ classname();

The above is the general syntax of a destructor. In the above, the symbol tilde ~ represents a destructor which precedes the name of the class.

Question 15.
Differentiate between ifstream and ofstream.
This ifstream class supports input operations on files and ofstream class supports output operations on files.

Question 16.
What is data independence? Mention the types of data independence.
Database systems are designed in multi-layers. A major objective for layer architecture is to provide data independence, which means that upper levels are unaffected by changes in lower levels.
There are two kinds of data independence:

• Logical data independence
• Physical data independence

Question 17.
Give the syntax and example for DELETE command in SQL.
It is used to delete/remove the tuples/rows from the table.
Syntax:
DELETE from tablename [WHERE Condition];
Example:
DELETE from student;

Question 18.
Explain half duplex communication mode.
In this mode, communication can take place between sending and receiving end in both directions, but only one direction at a time (not simultaneously). Example, walkie-talkie device.

PART – C

Answer any five questions. Each question carries three marks: (5 × 3 = 15)

Question 19.
What is a port? Explain serial port.
The ports are used to connect external devices like printers, keyboards or scanners and interface with the computer.
COM/Serial ports: [Component Object Model]
It is used for connecting communication devices like modems or mice. Serial ports provide the serial transmission of data of one bit at a time. There are two types namely, COM ports – 9 pin ports and 25- pin ports.

Question 20.
Write the logic diagram and truth table for NOR gate.
The logic diagram of NOR gate

Question 21.
Write an algorithm for PUSH operation in stack.
Algorithm for PUSH operation
PUSH(STACK, TOP, SIZE, ITEM)
Step 1: if TOP >= N-1 then
PRINT “stack is overflow”
Exit
End of if
Step 2: Top = TOP + 1
Step 3: STACK[TOP] = ITEM
Step 4: Return

Question 22.
What are the operations performed on pointers?
The various operations performed on pointers are:

1. Arithmetic operations can be performed.
2. Comparison of two pointers that belongs to same array.
3. Assign one pointer to another provided both pointers belongs similar type.
4. Increment and decrement operations etc.,

Question 23.
Give the function of put()> get() and getline() w.r.t. text files.
1. put() function
The put() function is used to write a single character to the associated stream.

2. get() function
The get() function is used to read a single character from the associated stream.

3. getline() function
The use of getline() function is to read a whole line of text.

Question 24.
Briefly explain one-tier database architecture.
The design of DBMS depends on its architecture. The DBMS architecture can be single tier or multi-tier. The dividing the system helps to modify, alter, change or replace on independent ‘n’ modules.

Logical one-tier architecture:
Here, DBMS is the only entity where DBMS user directly access database and uses it. Any changes made by the user directly done on DBMS itself. The database designers and programmers use 1-tier architecture.

Question 25.
What is a web browser? Mention any two web browsers.
It is a software application used to locate and display Web pages. A web browser is an interface between user computer and a remote web site. The two types of web browsers are Mozilla Firefox, Google Chrome, Internet Explorer, etc.,

Question 26.
Explain any three text formatting tags in HTML.
1. Bold Text:
You can bold text to emphasize information on your web page. Bold text is useful for introducing new terms and highlighting important phrases on a Web page.
Tag:
<B> SOME TEXT </B>
EXAMPLE:
<BODY> <B> THIS IS A Bold TEXT </B> </BODY>

2. Underline Text:
Tag:
<U> Some text </U>
Example:
<BODY> <U> You can underline this text </U> </BODY>

3. Italicise Text
Tag:
<I> SOME TEXT </I>
EXAMPLE:
<BODY> <I> THIS IS A ltilicize TEXT </I> </BODY>

PART – D

Answer any Seven of the following questions. Each question carries Five marks: (7 × 5 = 35)

Question 27.
Given the Boolean functionΣ(W,X,Y,Z) = (0,4,8,9,10,11,12,13,15). Reduce it by using Karnaugh map.

Quad 1: $$\overline{\mathrm{Y}}\overline{\mathrm{Z}}$$
Quad 3: $$\mathrm{W} \overline{\mathrm{X}}$$
Simplified expression: F(W, X, Y, Z) = $$\overline{\mathrm{Y}}\overline{\mathrm{Z}}$$ + WZ + $$\mathrm{W} \overline{\mathrm{X}}$$

Question 28.
Explain the General structure of C++ program with ah example.
The basic operation performed on arrays are
1. Traversing:
Accessing each element of the array exactly once.

2. Searching:
Finding the location of an element in the array.

3. Sorting:
Arranging the elements of the arrays in either ascending or in descending order.

4. Insertion:
Inserting an element in a given position of the array.

5. Deletion:
Deleting an element from the location in an array.

6. Merging:
Combing two more arrays to form a single array.

Question 29.
Write an algorithm to delete a data element from the queue.
Step 1: ifFRONT = -1 then
Print “Queue is Underflow”
Exit
End of if
Step 2: ITEM QUEUE [FRONT]
Step 3: if FRONT = REAR then
FRONT = 0
REAR = 0
Else
FRONT = FRONT + 1
Step 4: return

Question 30.
Explain the advantages of object oriented programming.
1. OOP provides a clear modular structure for programs. Large problems can be reduced tr
smaller and more manageable problems.

2. In OOP, data can be made private to a class such that only member functions of the class can access the data. This principle of data hiding helps the programmer to build a secure program.

3. Implementation details are hidden from other modules and other modules has a clearly defined interface.

4. It is easy to maintain and modify existing code as new objects can be created with small differences to existing ones.

5. With the help of polymorphism, the same function or same operator can be used for different purposes. This helps to manage software complexity easily.

6. In OOP, programmer not only defines data types but also deals with operations applied for data structures.

Question 31.
What is class definition? Write its general syntax and examp.
A class definition is a process of naming a class and data variables and interface operations of the class. A class is a structured datatype in C++which is a collection variables and functions.
The syntax of a class definition:

Question 32.
What is an inline function? Write a simple program for it.
When a member function is defined inside a class, we do not require to place membership label along with the function name. We use only small functions inside the class definition and such functions are known as inline functions. In case of inline function, program execution is faster but memory penalty is there.
Inline function C++ program:

Question 33.
What is a constructor? Give the rules of writing a constructor function.
Constructor is a special member function that is used to initialize the data members of an object. The rules for writing a constructor functions are

• They should be declared in the public section
• They are invoked automatically when the objects are created
• They should not have return types, therefore they cannot return values
• They cannot be inherited
• They can have default arguments
• These cannot be static

An object of a class with a constructor cannot be used as a member of a union.

Question 34.
What is inheritance? Explain any two types of inheritance.
In object-oriented programming, inheritance is a way to form new classes using classes that have already been defined.
1. Single inheritance:
A derived class with only one base class is called single inheritance. For example, If A is base class then class B derive from base class A.

2. Multilevel inheritance:
A class can be derived from another derived class which is known as multilevel inheritance. For example, The derived class C inherit B class whereas B is derived from class A.

Question 35.
What is data warehouse? Briefly explain its components.
A data warehouse (DW) is a database used for reporting. The data is offloaded from the operational systems for reporting. The components of data warehouse are data sources, data transformation, reporting, metadata, operations, and operational components.

In short, data is moved from databases used in operational systems into a data warehouse staging area, then into a data warehouse and finally into a set of conformed data marts. Data is copied from one database to another using a technology called ETL (Extract, Transform, Load).

Sourcing, Acquisition, Cleanup and Transformation Tools:
The functionality includes:

• Removing unwanted data from operational databases
• Converting to common data names and definitions
• Establishing defaults for missing data
• Accommodating source data definition changes

Meta data:
Meta data is data about data that describes the data warehouse. It is used for building, maintaining, managing and using the data warehouse.

Question 36.
Explain the various group functions in SQL.
The built-in functions associated with GROUP functions in SQL are

1. COUNT function:
returns the count of records that satisfies the condition for each group of records.
Example:
SELECT department, COUNT(*)FROM employees WHERE salary > 25000 GROUP BY department;

2. MAX function:
returns the maximum values from the column for each group of records.
Example:
SELECT department, MAX(salary) FROM employees GROUP BY department;

3. MIN function:
returns the lowest values from the column for each group of records.
Example:
SELECT department, MIN(salary) FROM employees GROUP BY department;

4. AVG function:
returns the average values from the column for each group of records.
Example:
SELECT AVG(cost) FROM products WHERE category = ‘Clothing’;

5. SUM function:
returns the total values from the column for each group of records.
Example:
SELECT department, SUM(sales)FROM order_details GROUP BY department;

6. DISTINCT function:
returns the once occurrence of many repeated values from the column for each group of records.
Example:
SELECT DISTINCT department from Employees;

Question 37.
Explain any five network devices.
1. Network Interface Cards:
The network interface card (NIC) provides the physical connection between the network and the computer workstation. Network interface cards are a major factor in determining the speed and performance of a network. The most common network interface connections are Ethernet cards.

2. Switches:
A switch is a hardware device that provides a central connection point for cables from workstations, servers, and peripherals. Switch forwards data only to the port on which the destination system is connected.

3. Repeaters:
Since a signal loses strength as it passes along a cable, it is often necessary to boost the signal with a device called a repeater. The repeater electrically amplifies the signal it receives and rebroadcasts it.

4. Routers:
Routers are network devices that route data around the network. By examining data as it arrives, the router can determine the destination address for the data; then, by using tables of defined routes, the router decides the best way for the data to reach destination. The router can direct traffic to prevent crash.

5. Hubs:
A network hub contains multiple ports. When a packet arrives at one port, it is copied to all ports of the hub for transmission.

The two types of hubs are active or passive hubs. Active hubs regenerate signal before forwarding it to all the ports and requires a power supply. Passive hubs, do not need power and they don’t regenerate the data signal.

6. Gateways:
It is a device that connects dissimilar networks. The term gateway is applied to any device, system, or software application that can perform the function of translating data from one format to another. The key feature of a gateway is that it converts the format of the data, not the data itself.

The conversion from one data format to another takes time, and so the flow of data through a gateway is always slower than the flow of data without one.

7. Modems:
Modem is a short form of the terms modulator and demodulator. Modems translate digital signals from a computer into analog signals that can travel across phone lines. The modem modulates the signal at the sending end and demodulates at the receiving end.

Modems provide a relatively slow method of communication. Modems are available as internal devices that plug into expansion slots in a system; external devices that plug into serial or USB ports;