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MOCK PRE-BOARD EXAMINATION: 2018-19

MARKING SCHEME

CLASS – XII

INFORMATICS PRACTICES ANSWER KEY

Time allowed :3hours Maximum marks : 70

General Instructions:

a) This question paper contains 6 Parts / Sections

b) All parts of questions should be attempted at one place.

c) Marks are given at the end of each question.

1.

(a) Name one Open Source Indian Operating System. 1

BOSS –Bharat Operating Systems Solutions

(b) What is Domain Name Resolution? 1

Domain Name Resolution is the process of getting corresponding IP address from

a domain name.

(c) Name two Indian Scripts included in UNICODE. 1

Assamese, Bengali, Devanagari, Gujarati, Gurumukhi, Kannada, Malayalam, Oriya,

Tamil and TeluguOR any 2 Indian Scripts

(d) An IT Help Desk executive needs to remotely login a customer‟s PC to provide him

technical support. Suggest a remote access software to him. 1

Teamviewer or Telnet

(e) Deepak wants to download/upload files from/to a remote internet server. Which

communication protocol will let him do the same. 1

FTP – File Tranfer Protocol

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(f) What was the objective behind developing UNICODE? 1

UNICODE was developed with the objective to conceive a single standard code to

represent most of the languages of the world.

(g) What is the name of the network topology in which each node is connected

independently using a switch? 1

Star or tree topology.

(h) Identify the type of network (out of LAN/PAN/MAN/WAN) formed in the given

diagram. 1

PAN

(i) How a Phonetic text entry is different from Keymap based text entry? 1

Phonetic text entry is different from keymap based text entry as in the keymap

based text entry keyboard keys are mapped to specific characters using a keymap

whereas in phonetic text entry text translation is done by some software based on

probable pronunciation of the entered text.

(j) What is denial of services? Explain briefly. 2

Denial-of-services attacks: are those attacks that prevent the legal users of a system from

accessing or using the resources, information or capabilities of a system. This term

is also used to refer to any outwardly induced condition that renders a computer

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unusable. It may be of following types:

a) Denial of Access to Information: Such attacks cause deletion or changing of impor

tant information to non-readable format.

b) Denial of Access to Applications: Such attacks make the applications unusable or

unavailablefor legal user of the system.

c) Denial of Access to Communications: Such attacks includes cutting of communication

wire, jamming radio communications, flooding a system with junk mail.

d) SYN flooding: It is a denial of service attack. It takes advantage of a loop hole in the way

TCP connection are created.

e) Pentium F00F Bug: It is a series of assembly language code sent to genuine Intel Pentium

processor that reboots a machine.

(k) Explain following terms. 2

(1) Apache Server (2) Linux

Apache Server : It is an open source web server for many platforms such as Linux, Unix,

MicrosoftWindows and other platforms.

Linux: It is a popular open source computer operating system. Freely available, freely used

it, modify it andredistribute it.

(l) List out any four advantages of Open Standards. 2

1) Making the data accessible to all.

2) Application and Platform independence

3) Diversity and inter operatibility in the industry

4) Offers diverse choices for users.

2.

(a) Give the code in HTML to display a Radio Button in an HTML form? Give example? 1

Ans:

<INPUT> tag is used.

e.g: <INPUT type = "Radio" name = "uname" />

(b) Give the code in HTMLto provide the hyperlink to a website www.tafssp.com.

Ans: <A HREF= “www.tafssp.com”> TAFS Website</A>

(c) Give the value of variable „a‟ after the execution of the following code: 1

int a;

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int s;

s=19;

a = (8 *(++s) % 3;

value of a will be1

(d) Identify the incorrect variable name and justify 1

i. unit$price; ii. fee; iii. userid; iv. 1avgmarks;

i. unit$price; // Special symbols like “$” not allowed in variable name

iv. 1avgmarks;// variable name cannot start with a number.

(e) What will be displayed in jTextField1 after the execution of the following loop? 1

double Number = 382.452;

jTextField1.setText( (Math.round(Number*10)) / 10.0 +”” );

382.5

(f) Write the output that will be generated by the code given below: 1

int A = 100, B ;

for (B=10; B<=12; B++)

A+=B;

JOptionPane.showMessageDialog(this,"A:"+A+" B:"+B+"");

a:133 B:13

(g) Give any two features of XML. Explain with the help of an example that we can create our

own tags in XML. 2

FEATURES OF XML

1. XML is designed to carry data not to display data.

2. XML was created to structure, store and to send information.

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3. XML is self-descriptive. Tags are not pre-

defned; rather they are created to describe the content in appropriate manner.

4. XML is free and extensible.

5. XML is platform independent.

XML tags are created by the user as there are no standard tags.

For example :

To store address , the tag <address> may be used as :

<address> Punjabi Bagh</ address >

(h) What will be displayed in jTextArea1 after the execution of the following loop? 2

for (int I=5;I<=20;I+=3)

jTextArea1.setText((jTextArea1.getText()+" "+Integer.toString(2*I))) ;

10 16 22 28 34 40

3.

(a) Give any two examples of common Database Management System. 1

MySQL, Ingres, Postgres, Oracle etc.

(b) Howis NULL value different from0(zero)value. 1

NULL means Unknown/No value/Empty while 0 is a numeric value.

(c) A table FOOD has 10 rows and 15 columns and table CUSTOMER has 12 rows and 8

columns. What is the cardinality and degree of the Cartesian product of the tables? 1

Cardinality 120

Degree 23

(d) WritethefollowingstatementusingIn clause which will result in the same output. 1

SELECT first_name, last_name, stream FROM details WHERE subject !=‟Commerce” or

subject!=” Science” or subject !=” Arts”;

SELECT first_name, last_name, stream FROM details

WHERE subject NOT IN („Commerce‟, „Science‟,‟Arts‟);

(e) What do you understand by ACID properties of database transaction? 2

Ans. -To ensure the data-ntegrity, the database system maintains the ACID properties of

a transaction. ACID properties-an acronym derived from the first letter of each

of the properties - Atomicity Consistency Isolation Durability.

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(f) Write the command to display last four characters of the text India . Also give the

command to find the first occurrence of character „n‟ in „Indian‟. 2

Select right(„India‟,4);

Selectinstr(„Indian‟,‟n‟);

(g) Consider the following table stud 2

admno Name

1 Abhimanyu

2 Akash

The following SQL queries are executed on the above table

INSERT INTO Stu VALUES(5,'Gagan');

COMMIT;

UPDATE Stu

SET name='Abhi' WHERE Admno = 1;

SAVEPOINT A;

INSERT INTO Stu VALUES(6,'Chris');

SAVEPOINT B;

INSERT INTO Stu VALUES(7,'Babita');

SAVEPOINT C;

ROLLBACK TO B;

What will be the output of the following SQL query now: SELECT * FROM Stu;

1 Abhi

2 Akash

5Gagan

6 Chris

4.

(a) How many times the following while loop gets executed? 1

int Product=1, i = 4;

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do

Product *= i ;

i--;

while( i== 4 );

1 time

(b) Define Object Oriented Programming. Is a class same as an object. Clarify. 2

OOP (Object Oriented Programming) CONCEPT The basic idea of OOP language is

to combine data and the functions that operate on this data into a single unit.

Class It is a collection of characteristics and behaviors of an entity. In java, class is a

collection of data members and member functions which operates on those members

into one unit. EgJTextField.

Object It is an instance of a class which uses the common behaviors and

characteristics of that class. JTextField1, JTextField2 are examples of object.

(c) The following code has some errors. Rewrite the correct code, Underlining all the

corrections made. 2

int y=10;

x == y + 5;

if( x = y);

jTextField1.getText( x + “ is equal to “ + y ); break;

jTextField2.setText( x + “ is not equal to “ + y);

int y=10;

int x = y + 5;

if( x == y)

jTextField1.setText( x + “ is equal to “ + y );

else

jTextField2.setText( x + “ is not equal to “ + y);

(d) What will be displayed in jTextField1 , jTextField2, jTextField3 and jTextField4 after the

execution of the following code: 2

String sms =”Picnic#Tomorrow”; //# represents a space

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int L= sms.length();

jTextField1.setText(Integer.toString(L));

jTextField2.setText(sms.toLowerCase());

jTextField3.setText(sms.substring(2,3));

jTextField4.setText(L.toLowerCase());

jTextField4.setText(Math.pow(L,2)+"");

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picnic#tomorrow

c

225

or

Explain the purpose of max() method with the help of suitable java code. Also mention that

max() method belongs to which class?

max() is a mathematical method, helps in calculating the maximum of any 2

numbers.

For example:

int num1=12,num2=44;

int ans=Math.max(num1,num2);

t1.setText(""+ans);

The above code will calculate the maximum of the two numbers and will give answer 44. max()

method belongs to Math class.

(e) Rewrite the following program code using switch case statement: 2

int day=Integer.parseInt(jTextField1.getText());

if(day>=1 && day<=6)

jOptionPane.showMessageDialog(this, "It is a working Day");

else if(day==7)

jOptionPane.showMessageDialog(this, "It is an off Day");

else

jOptionPane.showMessageDialog(this, "Invalid Day number");

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int day=Integer.parseInt(jTextField1.getText());

switch(day)

case 1:

case 2:

case 3:

case 4:

case 5:

case 6: jOptionPane.showMessageDialog(this, " It is a working Day ");

break;

case 7:

jOptionPane.showMessageDialog(this, " It is an off Day ");

break;

default:

jOptionPane.showMessageDialog(this, " Invalid Day number ");

(f) NDPL generates computerized bills for its customers on every month the bill is generated

fortwo consumption sections asfollows.

Consumption Section

1st 200 Units (Rs./Unit)

Next 200 Units (Rs./Unit)

Above 400 Units (Rs./Unit)

Domestic Light 2.45

3.95

4.65

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Create a Java Desktop application to read the number of units consumed and print out the charges.

Write the code for the following:

(a) The bill is to be displayed using JOptionPane, based on the table given above. 3

(b) When the user clicks on Non Domestic Light button, both JCheckBox control to be enabled

and set the checkbox Upto 10KW as selected. Write the code for Exit button to exit the application. 2

(c) When the user clicks Domestic Light button, disable the Up to 10KW and Above 10KW

buttons. 1

or

Write java statement if we want to add a new option “Commercial” in a combo box(cb1) at

run time. 2

(a)

private void jButton1ActionPerformed(java.awt.event.ActionEventevt)

int unit = Integer.parseInt(t1.getText());

double charge = 0 ;

if(drb.isSelected())

if(unit<=200)

charge = unit * 2.45 ;

Non Domestic Light Up to 10KW

5.40

5.40

5.40

Non Domestic Light Above 10KW

4.92

4.92

4.92

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else if(unit <= 400 && unit >200)

charge = (unit - 200) * 3.95 + (200 * 2.45) ;

else if(unit >400)

charge = (unit - 400) * 4.65 + (200 * 2.45) + (200 * 3.95) ;

else if(nrb.isSelected() &&upcb.isSelected())

charge = unit * 5.40 ;

else if(nrb.isSelected() &&abovecb.isSelected())

charge = unit * 4.92 ;

JOptionPane.showMessageDialog(rootPane, "Electricity charge = " + charge);

(b) if(nrb.isSelected())

upcb.setSelected(true);

upcb.setEnabled(true);

abovecb.setEnabled(true);

System.exit(0);

(c) if(drb.isSelected())

upcb.setEnabled(false);

abovecb.setEnabled(false);

or

cb1.addItem(“Commercial”);

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5.

(a) State difference between date functionsNOW()andSYSDATE()of MySQL. 2

NOW() returns the date and time at which the statement began to execute.

SYSDATE() returns the exact time at which the function executes.

Sleep argument pauses for the number of seconds given in the argument

(b) Consider the table Projects given below. Write commands in SQL for i to vi and output for vii

and viii. 8

PROJECTS

i. To display all information about projects of Medium ProjSize arranged in descending order of

cost.

Select * from projects where projsize=‟Medium‟ order by cost desc;

ID ProjName Projsize StartDate EndDate Cost

1 Payroll-MMS Medium 2016-03-17 2016-09-16 60000

2 Payroll-ITC Large 2018-02-12 2018-01-11 500000

3 IDMgmt-LITL Large 2018-06-13 2019-05-21 300000

4 Recruit-LITL Medium 2018-03-18 2018-06-01 50000

5 IDMgmt-MTC 2017-01-15 2017-01-29 20000

6 Recruit-ITC Medium 2017-03-01 2017-06-28 50000

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ii. To list the ProjSize of projects whose ProjName ends with LITL.

Select projsize from projects where projname=‟%LITL‟ order by cost desc;

iii. To list ID, name, size and cost of all the projects where projsize is not given.

Select id, projsize, name, cost from projects where projsize is NULL;

iv. To count the number of projects according to their size.

SELECT COUNT(*) FROM projects group by ProjSize.

v. To change the Cost of each project by applying 25% discount reduction.

Update project set cost = 0.75 * cost ;

Or

Update project set cost = cost - cost * 0.25 ;

vi. To add a new row for Project with the details as 7 for ID , "Recruit-MMTC" for projname.

Insert into Projects (id,Projname)values (7,‟ Recruit-MMTC‟);

vii. SELECT COUNT(DISTINCT(Projsize)) FROM projects;

2

viii. SELECTsum(Cost) FROM projects where projname=‟%ITC‟;

550000

6.

(a) Write a MySql command for creating a table “PAYMENT” whose structure is given below. 2

Table : PAYMENT

Field Name DateType Size Constraint

Loan_num Integer 4 Primary key

Payment_num Varchar 5

Payment_date Date

Payment_amt decimal 10,2 Not NULL

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CREATE TABLE PAYMENT

(Loan_numInteger(4)PRIMARY KEY,

Payment_numVARCHAR(5) NOT NULL,

Payment_datedate,

Payment_amtdecimal(10,2) Not NULL);

or

Help Aditya in identifying any four columns for a table named Flight along with their suitable data

types.

flightno char,

fname char

destination char

flight_date date

(b) Consider the following tables Product and Client. Write SQL commands for the statements

iand ii and answer the question iii.

Table : Product

P_ID PName Manufacturer Price

TP01 Talcom Powder LAK 40

FW05 FaceWash ABC 45

BS01 Bath Soap ABC 55

SH06 Shampoo XYZ 220

FW12 FaceWash XYZ 110

Table : Client

C_ID ClientName City P_ID

01 Cosmetic Shop Delhi FW05

06 Total Health Mumbai BS01

12 Live Life Delhi SH06

15 Pretty Woman Delhi FW12

16 Dreams Banglore TP01

i. To display the details of those products whose client‟s city is not Delhi . 2

Select P_id,Pname, Manufacturer, price From Product , Client where Client.P_ID =

Product.P_ID and city not like „Delhi‟;

or

Give the output of the following commands

Update Product set price = price –price*0.10 where price>100;

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select pname,price from product where price>90;

PName Price

Shampoo 198

FaceWash 99

ii. To display the Client name, City , Product Name and Manufacturer with their corresponding

matching P_ID. 2

Select ClientName,City,pname Manufacturer

From Product , Client Where Client.P_ID = Product.P_ID;

or

Discuss the significance of having clause with group by statement with suitable example.

Sometimes we do not want to see the whole output produced by a statement with Group

By clause. We want to see the output only for those groups which satisfy some condition.

It means we want to put some condition on individual groups (and not on individual

records). A condition on groups is applied by Having clause.

iii. Name the primary key and foreign key from both the tables. Can we enter TP02 in table Client?

if not why? 2

Product - P_ID primary key

Client - C_ID primary key, P_ID foreign key

No we cannot as it violates the Refrential Integrity rule.

or

Briefly explain the concept of Primary key and Candidate keys.

Primary Key: It is a field or collection of fields through which a record can be uniquely

identified in a table.

Primarykeysmayconsistofasingleattributeormultipleattributesincombination.

All the columns having capability to become Primary Key are known as Candidate Keys.

c. Give the MySql command - 2

i. To make Item_Noas the primary key in table Item, which the user forgot to make at creation time.

Alter Table Item

Add constraint primary key(Item_no);

ii. To change the width of column Item_Name to char(30)

Alter Table ITEM

Modify(Item_name char(30));