SCIENCE ENTRANCE ACADEMY III PREPARATORY EXAMINATION SCHEME OF VALUATION

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Computer Science (4) Q.NO Expand SCSI Small computer system interface PART-A Name the gate which produces output 0, if there are even numbers of s in the input XOR What is complete tree?

1 Computer Science (4) Q.NO Expand SCSI Small computer system interface PART-A Name the gate which produces output 0, if there are even numbers of s in the input XOR What is complete tree? Tree in which each leaf is at the same distance from the root. i.e. all the nodes have maximum two subtrees. 4 Name the two types of members referenced in a class? Data members and meber functions. What is free store? Free store is a pool of unallocated memory heap given to a program that is used by the program for dynamic allocation during execution. 6 Define is data mining? Data mining is concerned with the analysis and picking out relevant information. It is the computer, which is responsible for finding the patterns by identifying the underling rules of the features in the data. 7 Expand OSI. Open system interconnect 8 What are cookies? Cookies are messages that a web server transmits to a web browser so that a web server can keep track of the user s activity on a specific web site 9 What is WC? WC is acronym for World Wide Web Consortium. WC is responsible for producing the software standards for World Wide Web 0 Define dedicated hosting. In this type of hosting, the company wishing to go online, rents an entire web server from the hosting company. This is suitable for companies hosting larger websites State and prove complementarity laws? a) X +X = Proof by perfect induction: If X = 0, LHS = X+ X = 0 + = = RHS If X =, LHS = X + X =+ 0 = = RHS Thus X+ X = SCIENCE ENTRANCE ACADEMY III PREPARATORY EXAMINATION SCHEME OF VALUATION PART-B b) X. X=0 Proof by perfect induction: If X= 0, LHS = X. X = 0. = 0 = RHS If X =, LHS = X. X =.0 = 0 = RHS Thus X. X = 0 MARKS

2 Prove X.(X+Y)=X L.H.S=X.(X+Y) =X.X+X.Y =X+X.Y =X(+Y)=X=RHS Explain any two applications of OOP s.. Computer graphic applications. CAD/ CAM Software. Object -Oriented Database 4. User Interface design such as Windows. Real-time systems 6. Simulation and Modeling 7. Artificial intelligence and expert systems 4 Mention the features of default constructor. A constructor which does not accept any arguments is called a zero argument constructor. Features of default constructor are For every object created, this constructor is automatically called. All objects of a class are initialized to same set of values by the default constructor. If different objects are to be initialized with different values, it cannot be done using default constructor. Which are the types of data file. Text file:it is a file that stores information in ASCII characters. Binary file:it is a file that contains information in the same format as it is held in memory. 6 What is DBMS? Give an example for DBMS software. DBMS-DATABASE MANAGEMENT SYSTEM: A DBMS is a software that allows creation, definition and manipulation of database. DBMS is actually a tool used to perform any kind of operation on data in database. 7 Differentiate between ORDER BY and GROUP BY clause used in SQL. Give example for each. ORDER BY clause is used to sort the data in ascending or descending order, based on one or more columns. Some database sorts query results in ascending order by default. e.g.: select id,name from emp ORDER BY salary GROUP BY clause is used in collaboration with the SELECT statement to arrange identical data into groups. The GROUP BY clause follows the WHERE clause in a SELECT statement and precedes the ORDER BY clause. SELECT column, column FROM table_name WHERE [ conditions ] GROUP BY column, column ORDER BY column, column 8 What is communication (transmission) mode? Explain any one communication mode The communication mode defines in which data can flow depending upon the type media used. They are Simplex, Half Duplex and Full Duplex. Simplex: On this panel there is only one interface that is a transmitter and all other interfaces is a receiver. Half Duplex: On this channel each interface works as transmitter and receiver, but only one interface can transmit at a time. Full Duplex: This channel has two ends, each serving as transmitter and receiver. Each interface can transmit and receive at the same time. The modern telephone system use Full Duplex channels.

3 9 Explain different components of motherboard? Components of Motherboard Processor (CPU) BIOS CMOS Slots Disk Controllers I/O Ports and Interfaces BUS 0 Construct OR and NOT operation PART-C a) Using only NOR gate b) Using only NAND gate NOT using NOR logic A A A NOR A = A + A =A OR using NOR logic A B A + B (A NOR B) NOR (A NOR B) A+ = A + B NOR A + B = (A + B) + (A + B) = A + B [X+X=X] = A+B [X=X] Similarly using NAND Write an algorithm to delete an element from the array. Algorithm: A is the array with N elements. ITEM is the element to be deleted in the position P and it is stored into the variable Item. Step : Item = A[P] Step : for I = P to N- A[I] = A[I+] End of for Step : N = N- Step 4: Exit

4 4 Explain the operations performed on pointer We can add an integer value to a pointer. We can subtract an integer value from a pointer We can compare two pointers, if they point the elements of the same array We can subtract one pointer from another pointer if both point to the same array. We can assign one pointer to another pointer provided both are of same type. Discuss the file mode parameters in C++. File mode parameter Meaning Stream Type ios::app Append to end of file ofstream ios::in Open file for reading only ifstream ios::out Open file for writing only ofstream ios::ate Open file for updation and move ifstream,ofstream the file pointer to the end of file ios::binary Opening a binary file ifstream,ofstream 4 What are the advantages of random/direct access file organization? Random/Direct Access File Organization: Direct access file organization allow immediate direct access to individual records on the file. The record are stored and retrieved using a relative record number, which gives the position of the record in the file. This type of organization also allows the file to accessed sequentially. The primary storage in a CPU truly provides for direct access. There are some devices outside the CPU which can provide the direct feature; the direct access storage devices have the capability of directly reaching any location. Although there are several types of storage devices including discs and other mass storage. What are the services of E-commerce? Electronic Funds transfer(eft) Electronic Benefits transfer(ebt), Electronic forms(online admissions forms for college and other registrations) Digital cash(dc) Interoperable database access Bulletin Boards(BBs) Electronic Banking(EB) 6 Explain features of DHTML DHTML refers to web content that changes each time it is viewed. For example, the same URL could result in a different page depending on any number of parameters. Features in Dynamic HTML An object-oriented view of a Web page and its elements Cascading style sheets and the layering of content Programming that can address all or most page elements Dynamic fonts

5 PART-D 7 Given the Boolean function F W, X, Y, Z = π(0,4,8,9,0,,,,), reduce using K-map REDUCED FORM Y Z W X W Y W Y Z 8 Write an algorithm for insertion sort method. Algorithm: Let A be an array with N unsorted elements. The following algorithm sorts the elements in order. Step : for I = to N- Step : J = I While ( J >= ) If( A[J] < A[J-]) temp = A[J] A[J] = A[J-] A[J-] = temp If end J = J- While end for end Step :Exit 9 What is linear data structure? Explain the operations performed on linear data structure Linear data structures are a kind of data structure that has homogenous elements. Each element is referred to by an index. The linear data structures are Stack, Queues and Linked Lists. Traversal: The process of accessing each data item exactly once to perform some operation is called traversing. Insertion: The process of adding a new data item into the given collection of data items is called insertion. Deletion: The process of removing an existing data item from the given collection of data items is called deletion.

6 6 Searching: The process of finding the location of a data item in the given collection of data items is called as searching. Sorting: The process of arrangement of data items in ascending or descending order is called sorting. Merging: The process of combining the data items of two structures to form a single structure is called merging. 0 Give the difference between Procedural oriented programming and Object oriented programming ANY DIFFERENCE Write the general syntax for defining and declaring classes and objects. Explain the terms and give example. Syntax : class class_name { private: Variable declaration; Function declaration; public: Variable declaration; Function declaration; protected: Variable declaration; Function declaration; }; The keyword class is used to declare a class. The class_name is a User-defined name. The class body is enclosed within a pair of flower brackets followed by semicolon. The class body contains the declaration of data variables and functions. The Data variables are known as data members of a class. The Function declarations in a class are called Member functions. There may be zero or more member functions in a class. This is also known as interface. The private, protected, public are the access control specifiers. For Example : class item { private: int itemcode; public: void display(); }; Declaring object of a class (Declaration of a class): The declaration of objects is same as declaration of variables of basic data types. An object is an instance of a class template. When objects are created only during that moment the memory is allocated to them. Syntax: class classname { private: //members and methods public: }; classname object,object,. ;

7 7 For Example - : class student { private: int rollno; public: void getdata( ); }; student obj, obj; / / obj, obj are objects of class student When function overloading is needed? Write advantages and restrictions of function overloading. 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. Function overloading therefore is the process of defining same function name to carry out similar types of activities with various data items. The advantages of function overloading are: When different functions are created for different operations, then user has to call respective function depending on the situation. Instead, for different situations if the same function is called with different arguments using function overloading, then the compiler automatically decides about the appropriate function by comparing the argument types used in the call to the function 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 Restrictions on overloaded functions Each function in a set of overloaded functions must have different argument list. If typedef is used for naming functions, then the function is not considered as different type What is constructor? Give the rules for writing a constructor function A constructor is a special member function that is used in classes to initialize the objects of a class automatically. A constructor is a member function of a class with the same name as that of the class. A constructor is defined like other member functions of a class. It can be defined either inside the class definition or outside the class definition. It is called constructor because it constructs the values of data members of the class. The following rules are used for writing a constructor function: A Constructor always has name that is same as the class name of which they are the members. This will help the compiler to identify that they are the constructors. There is no return type for constructors (not even void). Since, the constructor is called automatically by the system, there is no program for it to return anything to; a return value would not make sense. A constructor should be declared in public section. A constructor is invoked automatically when objects are created. Constructors can have default arguments. It is not possible to refer to the address of the constructors. The constructors make implicit calls to the operators new and delete when memory allocation is required. 4 What is inheritance? Mention its types. Explain the advantages of inheritance Inheritance is the capability of one class to inherit properties from another class. Single inheritance Multilevel inheritance Multiple inheritance Hierarchical inheritance. Hybrid inheritance

8 8 Inheritance has following advantages: Reusing existing code Faster development time Easy to maintain Easy to extend Memory utilization Differentiate between hierarchical data model and network data model. Hierarchical model: This model was developed by IBM. Network Model: The network data model is that a parent node can This data model organizes the data in a tree-like have many child nodes and a child node can also structure, in which each child node can have have many parent nodes. This model was presented only one parent node. by CODASYL (conference on data systems languages). In this model, the data is also This data model comprises a set of records represented by a collection of records. The connected to one another through links. relationships among the data represented by links. The link is an association between two or more All the nodes are linked to each other without any records. hierarchy. In network model the data is organized is Advantage: both the retrieval and updates can in the form of graphs. be highly optimized by the DBMS. Disadvantage: the link is permanently established and cannot be modified. Advantage: It permits the modelling of many-tomany relationships in data. Disadvantage: it is complicated to maintain all the links. 6. Explain various group functions available in SQL Group Functions:- These functions group the rows of data based on the values returned by the query. These functions are used to calculate aggregate values like total or average, which return just one total or average value after processing a group of rows. Aggregate Functions in SQL are COUNT(), MAX(), MIN(), AVG(), SUM(), DISTINCT() 7. What is network security? Mention and explain protection methods. Network Security: To define the mechanism of providing security over network to the clients and servers. Network security is to make sure that only legal or authorized user and programs gain access to information resources like databases. Under this type of security, mechanisms like authorization, authentication, encrypted smart cards, biometrics and firewalls, etc are implemented. PROTECTION METHODS. Authorization: It determines whether the service provider has granted access to the web service to the requestor. Authorization confirms the service requestor s certificate.. Authentication: Authentication also termed as password protection as the authorized user is asked to provide a valid password and if he or she is able to do this, he or she considered to be an authentic user.. Encrypted Smart Cards: An encrypted smart card is a hand held smart card that can generate a token that a Computer system can recognize. Every time a new and different token is generated, which even though cracked or hacked, cannot be used later. 4. Bio Metric Systems: They form the most secure level of authorization. The Biometric systems involve some unique aspects of a person s body such as finger prints retinal patterns, etc. to establish his/ her identity. Firewall: A system designed to prevent unauthorized access to or from a private network is called firewall. There are several types of firewall techniques. i. Packet Filter ii. Application gateway iii.circuit Level Gateway iv. Proxy Server

Answer key SUBJECT : COMPUTER SCIENCE Time : 3 hour 15 min Max. marks : 70

Answer key SUBJECT : COMPUTER SCIENCE Time : 3 hour 15 min Max. marks : 70 I. Answer ALL the questions 10 x 1= 10 1. What is DHTML? Dynamic HTML is a term used to describe the combination of HTML, style