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ST. XAVIER’S SENIOR SECONDARY SCHOOL, JAIPURClass - XII – PRELIMS 2013: Answer Key

Subject – Informatics Practices (065)Date: 23-01-2013 M.M:70

Instructions: (i) All questions are compulsory(ii) Answer the questions after carefully reading the text.

SECTION – A (10 Marks)QA Answer the following questions:

A.1 (i) OSS: Open Source Software (ii) ODF: Open Document Format 2A.2 Denial of Service attacks are those attacks that prevent the il-legitimate users of the system from

accessing or using the resources, information or capabilities of the system. 2A.3 The open source comes with the source code. Whereas proprietary software comes without the source

code.Open source software is low cost, where as proprietary software is costly.The advantage of proprietary software is professional support and training available and the disadvantage is having closed standards that obstruct further development. The advantage of open source software is no license fee and having open standards that facilitates integration with other systems. And the disadvantage is lack of professional support. 2

A.4 Identify the type of topology from the following: 1A.4.1 STAR Topology

A.4.2 BUS/LINEARA.5 SMTP: Simple Mail Transfer Protocol 1A.6 UNICODE and ISCII 1A.7 Which of the following is not a feature of Networking? 1

(iii) Uninterrupted Power Supply

Section B (25 Marks)

QB Answer the following questions:

B.1 if statement will be used as we will be checking for range of values. 1B.2 t1.setEditable(false) 1B.3 combo box or a group of radio buttons. 1B.4 Fall through is a concept associated with ‘switch’ statement where the control falls to all the following

cases after the first matching case statement is found in the absence of ‘break’ statement. While ‘dangling else’ occurs when number of ‘if’ statements are more than number of ‘else’ statement and the question arises as to which ‘if’ the ‘else’ will belong to. 1

B.5 What will be the output of the following program code: 210 410 4

B.6 State and define the different types of Inheritance with neat diagram? 2Types of Inheritance:

1. Single Inheritance: when a class is derived from one base class ONLY.

2. Multiple Inheritance: when a class is derived from more than one base class.

A B

C

A

B

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3. Hierarchical Inheritance: when more than one class is derived from ONE base class.

4. Multi-Level Inheritance: when a subclass is derived from a class that itself is derived from another class.

5. Hybrid Inheritance:

B.7 What is the difference between Method overloading and Method Overriding? 2Method Overloading is when there are two methods with the same name but are different with respect to number and/or type of parameters they will receive.Method Overriding is when a method with the same name and signature is there in the sub-class as well as in super-class. Here the objects of the sub-class will override the method of the super class when the overridden method is called by them.

B.8 What is the difference between Call by Value and Call by Reference? 1In Call By Value, the value of the actual parameter is copied to the formal parameter. In this any change made by the formal parameter is not reflected back in the actual parameter. While in Call By Reference, the address of the actual parameter is passed on to the formal parameter. In this, whatever change the formal parameter will make will be reflected back in the actual parameter also.

B.9 What is the use of ‘extends’ and ‘new’ keyword in java? 1The ‘extends’ keyword will create an inherited class, while ‘new’ keyword will create an object of a class.

B.10 Mention any two differences between XML and HTML. 2XML tags are case sensitive while HTML tags are not.XML tags need a closing tag while HTML need not.XML is designed to transport and store data while HTML is designed to display data.

B.11 What will be the value of P and Q after execution of the following code? 113133

B.12 Rewrite the following program code using a Switch statement: 2

switch(code){case 1: Month = “January”;

break; case 2: Month = “February”;

break;case 3: Month = “March”;

break;case 4: Month = “April”;

break;default: Month = “No Match”;

break;}

A

B C D

A

B

C

A

B C D

B C D

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B.13 What will be displayed in jTextField1 after executing the following code? 232

B.14 . A class Electbill contains consumer details and another class Bill calculates the monthly electricity bill of a consumer. Details of the two classes are given below: (6)

class ElecBill {int cno;String name;String add;

public ElecBill(int c, String n, String a){cno=c;name=n;add=a;

}public void display(){

System.out.println(“Customer Number: ” + cno);System.out.println(“Customer Name: ” + name);System.out.println(“Customer Address: ” + add);

}} // end class ElecBill

class Bill extends ElecBill {int n; // no. of units

public Bill(int c, String n,String a, int units){super(c,n,a); // calling super class constructorn=units;

}

void calculate(){int amt=0;

if(n<=100) amt=500;else if(n<=200) amt= (1*n) + 500;else if(n<=300) amt=(1.20*n) + 500;else if(n>300) amt=(1.50*n) + 500;

super.display(); // calling super class methodSystem.out.println(“Total Bill Amount: ”+ amt);

}} // end class Bill

SECTION - C (35 Marks)

QC Answer the following questions:C.1 USE contacts; 1C.2 3 Records because equi-join will look only for matching values from the related fields. 1C.3 Not null constraint. 1C.4 Rows=8 Columns=3 1C.5 In a Database School there are two tables Employee and Dept as shown below: 2

C.3.1 deptnoC.3.2 VISHAKHA LIGHTS

MANISH DANCEC.6 The Doc_Name Column of a table Hospital is given below: 2

Based on the information, find the output of the following queries:(i) Sanjeev

(ii) DeepakSanjeev

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C.7 What is the purpose of ALTER TABLE command in MySQL? How is it different from UPDATE command?Alter Table command is used to make changes to the structure of the table i.e. adding new columns or new constraints, renaming columns, changing the type and/or size of a column or removing a column.Update command iss used to make changes to the row or records of a table. 2

C.8 Distinguish between a Primary Key and Candidate Key with the help of suitable examples of each. 2Primary key is a field that uniquely identifies a record in a table. Candidate key is a field that is a candidate to become a primary key.Ex. Regno field is a primary key of a table, while a field called mobileno is also a candidate to become a primary key of the table as it contains unique values for a record.

C.9 What is the purpose of DROP TABLE command? How is it different from DELETE command? 2Drop Table will delete the entire Table while Delete command will only remove the record/row from the table.

C.10 SELECT * FROM BOOK WHERE PRICE IS NULL; 2

C.11 Write MySQL command for creating a table “BANK” whose structure is given below: 2

CREATE TABLE BANK(ACCT_NAME INTEGER(4) PRIMARY KEY,NAME VARCHAR(3),BIRTHDATE DATE,BALANCE INTEGER(8) NOT NULL

);

C.12 Consider the table Doctor given below, write command in MySQL for (1) to (4) and output for (5) to (8).

C.12.1 SELECT NAME FROM DOCTOR WHERE EXPERIENCE>10 AND DEPT=’MEDICINE’ 1

C.12.2 SELECT DISTINCT DEPT FROM DOCTOR 1

C.12.3 SELECT MIN(CONSTfEE) FROM DOCTOR WHERE GENDER=’F’ 1

C.12.4 SELECT NAME,DEPT FROM DOCTOR WHERE GENDER=’M’ AND EXPERIENCE IS NULL 1

C.12.5 SELECT AVG(ConstFee) FROM Doctor WHERE NOT Gender=’F’; ½

362.5

C.12.6 SELECT Count(Experience) FROM Doctor; ½

4

C.12.7 SELECT Name, Experience FROM Doctor WHERE ID BETWEEN 100 AND 200; ½

J.P. PANDEY 9

S.P. SINHA NULL

C.12.8 SELECT SUM(ConstFee),MAX( Experience) FROM Doctor; ½

1900 12

C.13 Answer the following questions:

C.13.1 SELECT 1000 + SQRT (100) ; - 1010 1

C.13.2 SELECT SUBSTR ( ‘ST. XAVIER’S SCHOOL‘, 5 , 3 ) ; XAV 1

C.13.3 Difference between CHAR and VARCHAR data type. 1

CHAR IS FIXED SIZE WHIE VARCHAR IS VARIABLE SIZE

C.13.4 Differentiate between COMMIT and ROLLBACK. 1

COMMIT WIL SAVE ALL THE TRANSACTIONS MADE WHILE ROLLOBACK WILL UNDO ALL

THE TRANSACTIONS MADE

C.13.5 What is NULL value in MySQL database? Can you use nulls in arithmetic expression? 1

NULL IS AN EMTY VALUE AND IT CANNOT BE USE WITH ARITHMETIC EXPRESSIONS.

C.13.6 What is table alias? 1

IT IS ANOTHER NAME GIVEN TO A TABLE FOR DISPLAY PURPOSE ONLY

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QD Answer the following questions:D.1 Give one social impact of e-Business. 1

Compared with traditional commerce, e-commerce is a fundamentally different way of doing business. It is 24/7; global; anonymous; hugely competitive with quality, price and delivery easy to compare; it is cheaper to operate because telecoms is cheaper than transportation; it is very transparent with more info, less selling and more telling; payment is faster; it is more flexible and responsive for changes to offerings such as price and specification; business is place independent; methods of selling can be changed relatively easily.

D.2 Write three important features of e-Governance. Give URL of one of the commonly used e-Governance portals. 2

1. Speed – Technology makes communication speedier. Internet, Phones, Cell Phones have reduced the time taken in normal communication.

2. Cost Reduction – Most of the Government expenditure is appropriated towards the cost of stationary. Paper-based communication needs lots of stationary, printers, computers, etc. which calls for continuous heavy expenditure. Internet and Phones makes communication cheaper saving valuable money for the Government.

3. Transparency – Use of ICT makes governing profess transparent. All the information of the Government would be made available on the internet. The citizens can see the information whenever they want to see. But this is only possible when every piece of information of the Government is uploaded on the internet and is available for the public to peruse. Current governing process leaves many ways to conceal the information from all the people. ICT helps make the information available online eliminating all the possibilities of concealing of information.

4. Accountability – Once the governing process is made transparent the Government is automatically made accountable. Accountability is answerability of the Government to the people. It is the answerability for the deeds of the Government. An accountable Government is a responsible Government.

Examples: india.gov.in web.guidelines.gov.in www.nic.in indiaimage.nic.inD.3 Anuja is creating a form for her practical file. Help her to choose most appropriate controls from List

Box, Combo Box, TextField, TextArea, Radio Button, Check Box, Label and Command Buttonfor the following entries from user. 2(i) A message “Enter Marks” in front of a TextField. : LABEL(ii) An input to choose more than one subjects from a set of given choices.: CHECK BOXES(iii) An input for entering remarks. TEXTAREA(iv) An input for accepting Gender. RADIO BUTTONS/COMBOBOX