CBSE Class 12 Informatics Practices Sure Shot Questions Worksheet

Topic: Networking and Open Source Software (OSS)

Question. Two doctors in the same room have connected their palm tops using Bluetooth for working on a group presentation. Out of the following, what kind of networks they have formed? LAN,MAN,PAN,WAN.
Answer : PAN

Question. Arrange the following communication channels in ascending order of their data transmission rates. ETHERNET CABLE, OPTICAL FIBER, TELEPHONE CABLE, COAXIAL CABLE.
Answer : Telephone Cable, Ethernet Cable, Coaxial Cable, Optical Fiber

Question. Which transmission medium should be used to transfer data across two continents at very high speed?
Answer : Satellite

Question. Which of the following software’s are open source software:
LINUX,MS WINDOWS 7,PHOTOSHOP,MYSQL
Answer : Linux, MySQL

Question. Explain the difference between domain name and URL with the help of appropriate example of each.
Answer : Domain Name: It is the unique name of any website. Ex cbse.nic.in URL: Uniform Resource Locator – It is complete address of any website which contain protocol, domain name and webpage name. Example : http://www.cbse.nic.in/welcome.htm

Question. Name any two Indian scripts included in Unicode.
Answer : Gujarati, Punjabi, Malayalam

Question. Differentiate star and bus topology of networks.
Answer : Bus Topology: It is linear in nature. Each computer or server is connected to the single bus cable through some kind of connector.
Advantage: The bus topology consists of only one wire, it is rather inexpensive to implement as compared to other topologies.
Disadvantage: Since only one cable is utilized, it can be the single point of failure. If the network cable breaks, the entire network will be down.
Star Topology: In local area networks with a star topology, each network host is connected to a central hub.
Advantage: An advantage of the star topology is the simplicity of adding additional nodes.
Disadvantage: The primary disadvantage of the star topology is that the hub represents a single point of failure.

Question. Navneet is using software, which has been downloaded from internet and is available for one month.
After one month he has to pay license fee for further use. What software Navneet is using?
Answer : Shareware

Question. Akhil is transferring songs from his mobile to his friend’s mobile via Bluetooth connection. Name the network used by Akhil.
Answer : PAN

Question. Which of the following is not a characteristic of open source software?
I) Its source code is available for modification
II) Its owned by a company or an individual
III) It can be downloaded by Internet
Answer : II

Question. Which protocol is used for transfer of hyper text documents on the internet?
Answer : HTTP – Hyper Text Transfer Protocol

Question. Mr. Ramesh is working in an Global Organisation. He wants to login in his office’s computer from his home. Suggest the technology for the same.
Answer : Telnet

Question. Which device is used for connecting multiple networks over different protocols?
Answer : Gateway

Question. Identify the following topologies
i) A signal/data packets transmit from one end to other end in linear way.
ii) Each node is connected to two and only two neighboring nodes in circular form.
Answer : i) BUS ii) Ring

Question. What is the difference between free software and freeware ?
Answer : Free Software: It means software is freely accessible, free to use, changed, improved, copied, and distributed without any payments.e.g. LINUX
Freeware
Available free of cost
Copying and further distribution but not modification.
Source code is not available
E.g. Microsoft Internet Explorer

Question. Bholu is confused as he is unable to find the name of a network of computers and other devices that is confined to a relatively small space - an office. Help him do that.
Answer : LAN

Question. Most common communication protocol on Internet that ensures end-to-end communication, is?
Answer : POP – Point to Point Protocol

Question. What type of address is the following ? Also define it. 20 : B9 : Fl : 63 : 2F : FB
Answer : It is MAC Address (Media Access Control). It is given to hardware part to enable networking

Question. What are DoS attacks ?
Answer : Denial of Service (DoS): are those attacks that prevent the legal users of System from accessing or using the resources, information or capabilities of the system. It may be of following types :
Denial of Access to Information
Denial of Access to Applications
Denial of Access to Communications

Question. Write examples of one Proprietary and one Open Source Software.
Answer : Proprietary s/w: Microsoft Windows, MS Sql, ASP etc
Open s/w: Linux, MySQL, PHP etc.

Question. Expand following terms (i) FLOSS (II) SDLC (iii) GNU
Answer : (i) Free Libre Open Source Software (ii) System Development Life Cycle. (iii) GNU’s not unix

Question. What do you understand by TTF and OTF ?
Answer : TTF(True Type Font): True type is the native Operating System font format for windows and Mac
OS. True Type fonts are normally 8 Bit fonts.
OTF (Open Type Font): format is an extension of the TrueType font format. Open Type fonts are 16 Bit fonts. Open Type fonts allow the handling of large glyph sets using Unicode enconding.

Question. What was the objective behind developing UNICODE?
Answer : Unicode provides a unique number for every character, no mater what the platforms, no matter what the program, no matter what the language. Unicode can represent 94140 characters. Unicode standard has incorporated Indian Scripts under the group named Asian scripts. Indian scripts included as Devnagari, Bengali, Gurumukhi, Gujarati, Oriya, Tamil, Telgu, kannada, and Malayalam.

Question. Which of the following standard are open standards and which are proprietary standards ?
AIFF            ASX
OGG            FLAC
RM              HTML
Plain           Text WMA
SVG            JPEG
PNG
Answer : AIFF -   Proprietary ( Apple Machintosh) ASX - Proprietary (Microsoft)
OGG –                 Open FLAC - Open
RM –                    Proprietary (Real Media) HTML - Open
Plain Text –          Open WMA – Proprietary (Microsoft)
SVG –                  Open JPEG – Open
PNG–                   Open

Question. What is IP address?
Answer : (Internet Protocol Number):
Sometimes called a dotted quad. A unique number consisting of 4 parts separated by dots, e.g.
165.113.245.2. Every machine that is on the Internet has a unique IP number - if a machine does not have an IP number, it is not really on the Internet.

Question. Bhola wants to protect his private network from unauthorized access, which software/device should he install?
Answer : Firewall
Topic: JAVA

Question. Which property would you set for setting the password character as ‘$’?
Answer : setEchochar(‘$’)

Question. Which list property do you set for specifying the items for the list.
Answer : Model property

Question. Which method would you use to determine the index of selected item in a List Box?
Answer : getSelectedIndex()

Question. How one can make a Text Field un-editable on a Frame?
Answer : <jTextField>.setEditable(false)

Question. While working in NetBeans, Mr. Gupta wants to display “Pass” or “Needs to Reappear” message depending the marks entered in jTextfield. Help him to choose more appropriate statement out of “If” and “switch” statement.
Answer : If statement

Question. Write the value of variables x and y:
Int x,y;
X=7, y=5;
x=x+y++;
Answer : x=12
y=6

Question. How many times following loop will execute?
for(int i=1; i<=15; i++)
{
Syetem.out.println(“Hello”);
i=i+2;
}
Answer : 5 times

Question. Find the errors from the following code:
int m;n;
for(n=0,n<=10;n++);
m=+n;
Answer : int m,n;
for(n=0; n<=10; n++)
m+=n;

Question. Rewrite the following fragment using switch:
if (ch== ‘E’||ch==’e’)
System.out.println(“111”);
else if (ch== ‘W’)
System.out.println(“222”);
else if (ch== ‘N’)
System.out.println(“333”);
else
System.out.println(“444”);
Answer : Switch(ch)
{ case ‘e’ :
case ‘E’:
System.out.println(“111”);
break;
case ‘W’ :
System.out.println(“222”);
break;
case ‘N’ :
System.out.println(“333”);
break;
default : System.out.println(“444”);
}

Question. Find the output of the following code :
int i=1, j=0, n=0;
while (i<4) {
for(j=1; j<=i; j++)
{
n+=1;
} i=i+1;
}
System.out.println(“ “+n);
Answer : 10
Topic: HTML

Question. What is HTML?
Answer : HTML stands for Hyper Text Markup Language. It is a markup language used to create HTML documents. An HTML document defines a static web page. The <html> tag identifies the HTML document.
An HTML document begin with <html> ends with < /html >.

vGive two differences between HTML and XML.
Answer : The three differences between HTML and XML are:
1. HTML is designed to display data and hence, focused on the ‘look’ of the data, whereas XML is designed to describe and carry data and hence, focuses on data.
2. In HTML tags are predefined, while in XML, tags can be created as per needs.
HTML tags are not case sensitive, whereas XML tags are case sensitive

vWhich tag is used to specify :
a. Table data b. Table header c. Table row d. Table border
Answer : (a) <td> (b) <th> (c) <tr> (d) <tb>

Question. Which tag is used to define Ordered and Unordered list in HTML?
Answer : Bulleted/unordered list <UL> tag is used to indicate a list item as contained in an unordered or bulleted form.
The numbered/ordered list <OL> tag is used to indicate a list item as contained in an ordered or numbered form.

Question. Write the tag name to create horizontal line and break line
Answer : Horizontal Line: <hr>
Break Line: <br>

Question. Which tag and attribute of HTML is used to insert an image?
Answer : <img src=”Location”>
Topic: SQL

Question. Name the command to open an existing Database.
Answer : USE <database name>;

vA Table-Student has the following columns
Student_Id, Student_Name, Fathers_name, Class_Teacher_ID
Identify which column can act as Primary Key and Foreign Key
Answer : Primary Key: Student_Id
Foreign Key: Class_Teacher_ ID

Question. Define the terms Degree and Cardinality
Answer : Degree : Total number of columns in a table
Cardinality : Total number of Rows in a table

Question. Which command of SQL is used to display all tables of a Database.
Answer : SHOW TABLES;

Question. Name the command to add or modify a column in a table.
Answer : ALTER TABLE
Topic: IT Application

Q.48 define following terms. A) E-Governance, B) E-Business C) E-Learning
Answer : A) E-Governance : It refers to the application of electronic means in governance with a name of full filling the requirements of daily needs of user at affordable cost and in fastest possible time.
B) E-Business: It refers to any form of transactions that uses an electronic media to facilitate the transaction.
C) E-Learning: It refers to the means of teaching through technology such as Network browser, DVD, CD ROM etc.

Question. Give examples of any two web portals of E-Governance, E-Business and E-Learning.
Answer : E-Governance: www.india.gov.in, www.indianrail.gov.in
E-Business: www.homeshop18.com, www.amazon.in
E-Learning: www.kvselearning.in, www.w3schools.com www.ncert.nic.in

Question. What controls would you suggest for following types of inputs?
Answer : a) Enter Last Name b) Enter Address c) Gender d) Multiple items from a large no of options
a) Text Field b) Text Area c) Radio Button d) List Box

Q1. Design a ‘Raised to Power’ application in JAVA to accept 2 numbers from user and calculate the result. Also set a Reset button in the application.

Q2. Design an application in JAVA which accepts a fractional number from user and round it off to 0,1,2,3 digits as per user’s choice.(Use Radio buttons to accept choice input and Math class for rounding off.)

Q3. Develop a ‘Case Changer’ application in JAVA which accepts a string input from user and displays it in Lower case and upper case.(Use case conversion methods - toUpper Case () and toLower () )

Q4. Develop an application in JAVA which accepts the First Name, Middle name and the Last Name from user and display the short name. (i.e. Last name followed by his initials.)

Q5. Design an application to calculate Simple Interest. Accept Principle, Rate and Time from user. (Hint: S.I. = (P ∗ R ∗ T)/100)

Q6. Design an Area Calculator capable of calculating the area of a circle, square and Rectangle.(Use Radio buttons to accept figure input and use the visibility, border, enabled and editable properties to make the application presentable .)

Q7. Design a basic calculator in JAVA which accepts two numbers from user and calculates sum, difference, product, quotient as per the user’s choice. (Based on the use of Arithmetic operators)

Q8. Design an application in JAVA to accept Name as input and display the name with title i.e. If male add Mr to it and if Female add Ms to it (Use radio buttons for selection input) 

Topic: Networking and Open Source Software

Question. Which transmission medium should be used to transfer data across two continents at very high speed?
Answer : Satellite

Question. Two Engineers in the same room have connected their mobile using Bluetooth for working on a group presentation. Out of the following, what kind of networks they have formed? LAN,MAN,PAN,WAN.
Answer : PAN

Question. Arrange the following communication channels in descending order of their data transmission rates.
ETHERNET CABLE, OPTICAL FIBER, TELEPHONE CABLE, COAXIAL CABLE.
Answer : Telephone Cable, Ethernet Cable, Coaxial Cable, Optical Fiber

Question. Which of the following software’s are open source:
LINUX,MS WINDOWS 7,PHOTOSHOP,MYSQL
Answer : Linux, MySQL

Question. Explain the difference between domain name and URL with the help of appropriate example of each.
Answer : Pls see the example : http://www.cbse.nic.in/welcome.htm
Domain Name: It is the name of any website. Ex cbse.nic.in
URL: Uniform Resource Locator – It is complete address of any website which contain protocol, domain name and webpage name.

Question. What do you mean by network topology? Name most popular topologies
Answer : Network topology is defined as the interconnection of the various elements (links, nodes, etc.) of a computer network.
The study of network topology recognizes five basic topologies:
Bus topology , Star topology, Ring topology, Tree topology, Mesh topology

Question. Puneet is using software, which has been downloaded from internet and is available for one month.
After one month he has to pay license fee for further use. What software Puneet is using?
Answer : Shareware
Ans: II

Question. Which protocol is used for transfer of hyper text documents on the internet?
Answer : HTTP – Hyper Text Transfer Protocol

Question. What type of address is the following ? Also define it. 20 : B9 : Fl : 63 : 2F : FB
Answer : It is MAC Address (Media Access Control). It is given to hardware part to enable networking

Question. What is IP address?
Answer : (Internet Protocol Number):
Sometimes called a dotted quad. A unique number consisting of 4 parts separated by dots, e.g.
165.113.245.2. Every machine that is on the Internet has a unique IP number - if a machine does not have an
IP number, it is not really on the Internet.
Identify these address : i) 192.168.1.25 ii) 20 : B9 : Fl : 63 : 2F : FB
It is IP address
It is MAC address.

TOPIC : HTML

Question. Give two difference between HTML and XML.
Answer : The two differences between HTML and XML are:
1. HTML is designed to display data and hence, focused on the ‘look’ of the data, whereas XML is designed to describe and carry data and hence, focuses on
2.HTML tags are not case sensitive, whereas XML tags are case sensitive

Question. Which tag is used to specify :
a. Table data
b. Table header
c. Table row
d. Table border
Answer : (a) <td> (b) <th> (c) <tr> (d) <tb>

Question. What is an unordered list?
Answer : Bulleted/unordered list <UL> tag is used to indicate a list item as contained in an unordered or bulleted form.

Question. What is ordered list?
Answer : The numbered/ordered list <OL> tag is used to indicate a list item as contained in an ordered or numbered form.

Question. What do you understand by ALINK? Give an example.
Answer : Links which are currently being visited in web page are known as Active Links (ALINK). Example:
<BODY TEXT = “#FFFFFF” ALINK=”#FF0000”>
<A HREF=”www.kvsangathan.nic.in”> Kendriya Vidyalaya Sangathan </A><BR> <A HREF = www.cbse.nic.in&gt;
Central Board of Secondary Education </A> </BODY>

IT APPLICATIONS

Question. define following terms.
E-Governance
E-Business
E-Learning
Answer : E-Governance : It refers to the application of electronic means in governance with a name of full filling the requirements of daily needs of user at affordable cost and in fastest possible time.
E-Business: It refers to any form of transactions that uses an electronic media to facilitate the transaction.
E-Learning: It refers to the means of teaching through technology such as Network browser, DVD, CD ROM etc.

Question. Give examples of any two websites of E-Governance, E-Business and E-Learning.
Answer : E-Governance: www.india.gov.in, www.indianrail.gov.in
E-Business: www.homeshop18.com, www.amazon.in
E-Learning: www.kvselearning.in, www.w3schools.com www.ncert.nic.in

Question. What controls would you suggest for following types of inputs?
Typed text(Single Line)
Typed Text(Multiple Lines)
A Mouse click
One out of many choices
Multiple choices from a set
Multiple items from a group of names
Typed text which should remain hidden
Answer : Text Field
Text Area
Button / Radio Button / Check Box
Radio Button
Check Box
List Box
Password field

Topic :-NetBeans (JAVA)

Question. Name any two swing containers.
Answer : jFrame, jPanel

Question. Which property would you set the setting the password character as ‘$’?
Answer : setEchochar(‘$’)

Question. Which method you would use to insert ‘Hello’ at 10th position in the Text Area control.
Answer : void insert(“Hello”,10)

Question. Which method returns the password entered in a password field?
Answer : getPassword()

Question. Which list property do you set for specifying the items for the list.
Answer : Model

Question. Which method would you use to determine the index of selected item in a list?
Answer : getSelctedIndex()

Question. How one can make a Text Field un-editable on a Frame?
Answer : <jTextField>.setEditable(false)

Question. How one can make a Label invisible on a frame?
Answer : <jLabel>.setVisible(false)

Question. While working in NetBeans, Mr. Gupta wants to display “Pass” or “Needs to Reappear” message depending the marks entered in jTextfield. Help him to choose more appropriate statement out of “If” and “switch” statement.
Answer : If statement

Question. Which Methods is use to display message on screen using JOptionpane ?
Answer : showMessageDialog Box ();

Question. Write any two differences between while and do-while loop?
Answer : Entry control – Exit Control

Question. Runs if condition is true – runs at least once
Answer : 10

Question. Write the code for clear and exit button for the given application.
Answer : Code for Clear Button
JtextField1.setText(null);
JtextField2.setText(null);
JtextField3.setText(null);
JtextField4.setText(null);
JtextField5.setText(null);
Code for Close Button
System.exit(0);

Question. Name the command to open a Database
Answer : USE

Question. What command is used to see all the existing Tables in the database
Answer : Show Tables

Question. Name the command use to see all ‘Databases’ in the system.
Answer : Show Databases

Question. Name the command use to create a table
Answer : Create Table

Question. Name the command to show the structure of an existing table
Answer : DESC <Table Name>

Question. Name the various keys you know.
Answer : Primary Key, Candidate key, Alternate key, Foreign Key

Question. Write two characteristics of a Primary key?
Answer : It cannot be NULL
It is unique

Question. What is the difference between Candidate Key and Alternate key
Answer : Candidate Key: An attribute or group of attributes that can act as a Primary Key is Called Candidate Key.
Alternate Key : All Candidate key other than the Primary key are called Alternate Key.

Question. What is a Foreign Key?
Answer : Foreign Key is a Non-Key attributes, which obtains its values for the primary key of a parent table.

Question. Name the Command use to add a new record in an existing table
Answer : Insert into

Question. Name commands for changing Table Data and changing Table Structure
Answer : Changing Table Data: Update
Changing Table Structure: Alter Table

Question. What is the difference between the following pair of Commands:
Delete from stu;
Drop table stu
Answer : Delete from emp will remove all records from table emp but will keep the empty table, but , Drop table
emp will not only remove all the records but also the table.

Question. Define the terms Degree and Cardinality
Answer : Degree : Total number of columns in a table
Cardinality : Total number of Rows in a table

Question. What is a Join?
Answer : The horizontal joining of two or more tables base on a common column between the joining table is called
Join

Question. Name few type of Joins
Answer : Inner Join , Outer Join, Left Join , Right Join

Question. What is a Cartesian Product?
Answer : The Cartesian product, also referred to as a cross-join, returns all the rows in all the tables listed in the
query. Each row in the first table is paired with all the rows in the second table.

Question. What is the difference between NULL and ZERO?
Answer : NULL is nothing not even zero or blank, it does not occupy any space on the disk but zero is a numeric
value, it occupies space on memory.

Question. While using SQL pattern Matching, what is the difference between ‘_’ and ‘%’
Answer : ‘_’ represents any string of zero or more characters.
‘%’ represents Any string of zero or more characters.

Question. Name various Transaction control Commands?
Answer : SAVEPOINT: creates points within groups of transactions in which to rollback
COMMIT: to save the changes.
ROLLBACK: to rollback the changes.