Download - Kendriya Vidyalaya No.1 Sagar

CHAPTER-WISE QUESTION ANSWERS FOR SLOW BLOOMERS
SUBJECT - INFORMATICS PRACTICES
CLASS – XII
NAME – SK GUPTA
DESIG – PGT (C.Sc.)
CHAPTER-WISE QUESTION ANSWERS FOR SLOW BLOOMERS
SUBJECT - INFORMATICS PRACTICES
CLASS – XII
CHAPTER 1 – COMPUTER NETWORKING
Q .1. What is meant by Network Topology?
Ans: The pattern of interconnection of nodes in a network is called the network
topology. Major topologies are:
a. Star
b. Bus
c. Ring or Circular
d. Tree
e. Graph
Q. 2. What are Bridges? How do they differ from Repeaters?
Ans: Bridge is a device that links two networks together. Bridges differ from repeaters
in their capability of deciding whether a particular message is to be communicated on
the other side or not where as a repeater just amplifies the signal and pass it to other
side.
Q. 3. Give the full form for the following:
a. MODEM
b. FM
c. AM
d. NFS
e. FTP
Ans:
i.
Modulator Demodulator
ii.
Frequency Modulation
iii.
Amplitude Modulation
iv.
Network File Server
v.
File Transfer Protocol.
Q. 4. How is Coaxial cable different from Optical Fibre?
Ans:
Coaxial cables
Coaxial cables have solid wire core
surrounded by one or more foil or
wire shields.
Coaxial cables transmit electrical
signals.
Optical fibres
Optical fibres consist of thin strands
of glass or glass like materials.
Optical fibres transmit light signals
or laser signals.
Q.5- What do you understand by Firewall?
Ans: The system designed to prevent unauthorized access to or from a private network
is called firewall.
CHAPTER 2 – OPEN SOURCE CONCEPTS
Q6 – What is OSS?
Ans – OSS is Open Source Software. It is software whose source code is available and
which can be copied, modified & redistributed as well. There may or may not be charges
payable for open source software.
Q.7 – Differentiate between Freeware & Shareware.
Ans – Freeware – It is software which is available free of cost and which allows copying
and further distribution, but not modification and whose source code is not available.
Shareware - It is software which is made available with the right to redistribute copies,
but it is stipulated that if one intends to use the software, often after a certain period of
time, then a license fee should be paid.
Q.8 – What is openoffice.org?
Ans – Openoffice.org is an office application suite. It is intended to be compatible, and
directly compete with Microsoft Office. It is free software and is available for Microsoft
Windows, Unis-like systems and Mac OS X.
Q.9 – Name two categories of standards.
Ans –The two categories of standards are – Proprietary & Open Standard.
Q.10 – What are different font categories?
Ans – On the basis technical specifications, fonts can be categorized as –
1. True type font
2. Open type font
Q.11 – Define the terms – ODF, Ogg Vorbis.
Ans – ODF (Open Document Format) – The ODF is an XML based file format for
representing electronic documents such as formatted text documents, spreadsheets,
electronic presentations, graphics etc. it is an open format and free.
Ogg Vorbis – It is a new Audio Compression format which is an Open format developed
by Xiph.org. it is different from other formats because it is completely free, open and
unpatented.
Q.12 – What is Indian Script keymap known as?
Ans – The Indian script Keymap is known as Inscript Keymap.
Q.13 – What is the significance of Unicode in terms of Indian Language Computing?
Ans – Unicode provides a unique number for every character, no matter what the
platform, no matter what the program, no matter what the language. Unicode is
supported in many operating systems, all modern browsers, and many other products. It
allows data to be transported through many different systems without corruption.
CHAPTER – 3 : JAVA GUI PROGRAMMING REVISION TOUR – I
Q.14 – How is ordinary compilation process different from Java compilation?
Ans – In ordinary compilation, the source code is converted to a machine code, which is
dependent upon the machine or the platform. This resultant machine code is called
native executable code. On the other hand, Java compiler does not provide native
executable code for a particular machine. Instead it produces a special format called
byte code. The Java Byte code looks a lot like machine language, but unlike machine
language Java byte code is exactly the same on every platform.
Q.15 – What do you understand by Visual Programming?
Ans – Visual is a method to create GUI applications. The visual programming style
involves a lot of illustrations i.e, graphic entities, rather than writing numerous lines of
code to describe the appearance, functioning etc. of the applications interface.
Q.16 – What is the difference between an event and a message?
Ans – An event refers to the occurrence of an activity, whereas a message is the
information or request sent to the application. Each time an event occurs, it causes a
message to be sent to the operating system.
Q.17 – What are containers or container controls?
Ans – A container is a control that can hold other controls within it e.g., a Frame or a
label or simply window. Controls inside a container are known as child controls. The
child controls can exist completely inside their containers. When we delete a container
control , all its child controls automatically gets deleted.
Q.18 – What is the relationship between properties, methods and events?
Ans – Properties are an object’s attributes, methods are its actions, and events are its
responses.
Q.19 – How is if..else different from switch statement?
Ans – The switch statement must be controlled by a single integer control variable, and
each case section must correspond to a single constant value for a variable. The if..else
statement allows any kind of condition after each if.
Q.20 – Give the output of the following code:
int m = 100;
while ( m > 0 ) {
if ( m < 10 )
break;
m = m – 10;
}
system.out.println(“ m is “ + m);
Ans – No output ; Infinite loop.
Q.21 – Write a Java program to find out whether a year ( 4-digit number stored in
variable year) is a leap year.
Ans –
if ( year % 100 == 0)
{
if ( year % 400 == 0)
system. Println( year + “ is a century year and leap year”);
else
system. Println( year + “ is a century year but not a leap year”);
}
else if( year % 4 == 0)
system. Println( year + “ is a leap year”);
else
system. Println( year + “ is not a leap year”);
Q.22 – Write Java code that takes value for a number n in JTextField1 and cube of it to
be displayed in JTextField2.
Ans –int n = Integer.ParseInt( JTextField1.getText());
jTextField2.setText(“ ” + (n * n * n));
Q.23 – How many times the following while loop get executed?
int k = 5;
int l = 36;
while ( k <= l)
{
k += 6;
}
Ans – 6 times.
CHAPTER – 4 : JAVA GUI PROGRAMMING REVISION TOUR – II
Q.24 – Define GUI. How can you create a GUI application on Java Platform?
Ans – A GUI( Graphical User Interface) is an interface that uses pictures and other
graphic entities along with text, to interact with user. We can create Java applications on
Java Foundation Classes (JFC).
Q.25 – Name two containers for each of the following categories:
(i) top level (ii) middle level
(iii) component level
Ans - Top level containers – Jframe, JDialog
Middle level containers – Jpanel, JTabbedPane
Component level containers – Jbuuton, JLabel
Q.26 – What command do you need to write in actionPerformed( ) event handler of a
button, in order to make it exit button?
Ans – System.exit(0) ;
Q.27 – What method would you use, in order to simulate a button’s (namely OKButton)
click event, without any mouse activity from user side?
Ans – OKButton.doClick( ) ;
Q.28 – How would you set a label to have both an image as well as text?
Ans – The icon property of the label should be set by the path of the specific image and
the text property should be set with the specific text.
Q.29 – Name the Java Classes that implement text field, password field and text area.
Ans - (i) Text field – JtextField
(ii) Password field – JasswordField
(iii) Text area – JtextArea
Q.30 – Differentiate between a Text field and a Text area.
Ans – A Text field’s text property can hold single line of text unless it is an HTML text.
Whereas a text area’s text can hold an number of lines of text depending upon its rows
property.
Q.31 – What is the difference between a text field and a password field?
Ans – Both text field and password field can obtain a single line of text from the user. A
password field displays the obtained text in encrypted form on screen while text field
displays the obtained text in unencrypted form.
Q.32 – Which event gets fired when –
1. User presses enter in a text field.
2. User presses enter in a password field.
3. Knob of a scrollbar is dragged.
4. A checkbox is clicked.
5. A radio button is clicked.
6. Knob of a slider is dragged.
Ans - 1. Action Event 2. Action event 3. Adjustment event
4.Item Event
5. Item event
6. Change event
Q.33 – How is a list different from a combobox?
Ans –
S.N
1
2
3
List
It is a
graphic
al
control
that
displays
a list of
items in
a box
wherefr
om the
user can
make
selectio
ns.
It
doesn’t
have a
text
field.
The
user
must
Combo box
o
.
It appears as a text field along with a drop down list arrow
from which the user can choose a value.
It is a cross between a text field and list.
User can edit if he/she wishes.
4
select
items
from
the list
directly.
It allows It allows only single item selection.
user to
select
more
than
one
item.
Q.34 – Given a string object named pay having value as “3850” stored in it. Obain the
output of the following –
JOptionPane.showMessageDialog(null, “ ” + salary.length( ) + Integer.parseInt(salary));
Ans – 43850
Q.35 – What will be displayed in jTextArea1 after executing the following statement –
jTextArea1.setText( “Live\nIn Peace\tand harmony”);
Ans – Live
In Peace
and harmony
CHAPTER – 5 : INTRODUCING CLASSES, OBJECTS AND INHERITANCE
Q.36 – Define a class with reference to object oriented programming.
Ans – A class is a blueprint that represents an object’s structure. It encapsulates
object’s data and associated behavior.
Q.37 – Write a method that takes a number as argument and displays the sum of all the
digits in the number. Implement the method through a GUI application that obtains a
number in a text field, computes the sum of its digits and displays in a label.
Ans – Method –
Int sumDigits( int n) {
Int sum = 0;
Int dig;
While( n > 0 ) {
Dig = n % 10;
Sum = sum + dig;
N = n / 10;
}
Return sum;
}
Code for actionPerformed( ) method of button –
Int num = Integer.parseInt( numTF.getText( ) );
Int sum = sumDigits(num);
Label.setText(“ Sum of its digits s : “ + sum);
CHAPTER – 6 : COMMONLY USED LIBRARIES
Q.38 – Differentiate between String and StringBuffer objects.
Ans – The string objects of Java are immutable i.e., once created, they cannot be
changed. If any change occurs in a string object, then original string remains unchanged
and a new string is created with the changed string.
Stringbuffer objects are mutable, on the other hand. That is, these objects can be
manipulated and modified as desired.
Q.39 – What will be the output of the following code snippet when combined with
suitable declarations and run?
StringBuffer city = new StringBuffer(“Madras”);
StringBuffer string = new StringBuffer( );
String.append( new string(city));
String.insert(0, “Central”);
String.out.println(string);
Ans – CentralMadras
Q.40 – What will be the output of the following code fragment if “abc” is passed as
argument to the func( )?
Public ststic void func( String s1) {
String s = s1 + “xyz”;
System.out.println(“s1 = “ + s1);
System.out.println(“s = “ + s);
}
Ans – s1 = abc
S = abcxyz
Q.41 – Explain the difference between the string methods “equals” and “compareTo”.
Ans – If s1 and s2 are strings, then s1.equals(s2) returns a Boolean value indicating
whether the text inside strings s1 and s2 are equal or not. On the other hand,
s1.compareTo(s2) returns an integer value. The returned value is less than 0 if s1 comes
before s2 lexicographically, greater than 0 if s1 comes after s2lexicographically and 0 if
s1 and s2 contains same text.
CHAPTER – 7 : CONCEPT OF INHERITANCE
Q.42 – Why was the concept of Inheritance introduced in Object Oriented languages?
Ans – The concept of Inheritance was introduced in Object Oriented Languages
because of the following reasons –
1. Inheritance is capable of expressing the inheritance relationship of real world
models.
2. Inheritance facilitates the code reusability. Additional features can be added to a
class by deriving a class from it and then by adding new features to it. Class once
written and tested need not be rewritten or redefined.
3. Inheritance is capable of simulating the transitive nature of real world’s
inheritance, which in turn saves on modification time and efforts, if required.
Q.43 – What type of Inheritance does Java have?
Ans – Java supports only three types of Inheritance –
1. Single Inheritance
2. Multilevel Inheritance
3. Hierarchical Inheritance
Q.44 – A class vehicle and its subclass car both have a method speed( ). If Maruti is an
object of class type car. What will happen if following statement is issued?
Maruti.speed( );
Ans – The given statement will invoke speed( ) method defined in class car. It will not
invoke the speed( ) method defined in class vehicle.
Q.45 – How do you prevent a subclass from having access to a member of a superclass?
Ans – To prevent a subclass from having access to a member of a superclass, the
members can be declared as private.
Q.46 – What is an Abstract Class?
Ans – An abstract class contains at least one abstract method.
CHAPTER – 8 : DATABASE CONNECTIVITY TO MYSQL
Q.47 – What is Database connectivity?
Ans – Database connectivity refers to connection and communication between an
application and a database system.
Q.48 – What do you understand by ODBC? How is JDBC different from ODBC?
Ans –
S.No.
ODBC
1
ODBC (Open Database
Connectivity) is a framework used
by Microsoft to connect to various
types of databases.
2
3
ODBC provides database
connectivity to non-Java front end
applications.
ODBC is language independent as
it can work with any language.
JDBC
JDBC (Java Database
Connectivity) is a framework
developed by Sun Java to help
Java connect to different
databases.
JDBC provides database
connectivity from within Java
applications to databases.
JDBC is language dependent as
it works only for Java.
Q.49 – What tasks does JDBC perform?
Ans – JDBC performs the following tasks from within Java application code:
1. Establishing a connection with a database.
2. Sending SQL statements to database server.
3. Processing the results obtained.
Q.50 –What is connection? What is its role?
Ans – A connection is the session between the application program and the database.
To do anything with database, one must have a connection object.
Q.51 – Which Package’s Classes must be included as part of your Java application for
database connectivity to work?
Ans – java.sql
Q.52 – What is a result set?
Ans – A resultset refers to a logical set of records that are fetched from the database by
executing a query and made available to the application programs.
Q.53 – What are the steps involved in establishing a JDBC connection?
Ans – For establishing JDBC connection, following steps are involved –
1. Loading th JDBC driver.
2. Making the connection.
Q.54 – How can you load the drivers?
Ans – For loading the drivers following statement should be included –
Class.forName(“com.mysql.jdbc.Driver”);
CHAPTER – 9 : WEB APPLICATION DEVELOPMENT
Q.55 – What do you understand by URL and Multimedia?
Ans – URL: URL is Uniform Resource Locator. A URL refers to an address on the
internet. Billions of documents/ multimedia files can be accessed on internet through
their URLs.
Multimedia: It refers to usage of multiple media such as text, photographs, graphics,
video and audio at the same time. A multimedia file is a combination of media like text,
photographs, grphics, video and audio.
Q.56 – What is a protocol?
Ans – A protocol is a set of rules governing an operation or application.
Q.57 – Differentiate between a Web browser and a Web server.
Ans – A www client is called a web browser and a www server is called a web server. A
web browser navigates through the world wide web and displays pages. The web
browser requests a page from a web server. The web server makes available the desired
page to web browser.
Q.58 – What is Client server computing?
Ans – Client/ Server describes the relationship between two computer programs in
which one program , the client, makes a service request from another program, the
server, which fulfills the request. In a network, the client/ server model provides a
convenient way to interconnect programs that are distributed efficiently across different
locations.
Q.59 – What is www?
Ans – World Wide Web (www) is an example of an information protocol/ service that
can be used to send and receive information over the internet. It supports –
1. Multimedia information
2. Hypertext information
3. Graphic User Interface
CHAPTER – 10 : HTML-1: BASIC HTML ELEMENTS
Q.60 – Write a sample HTML code to display an address in exactly the same way as
given here:
John Parera
<H14>, Green Valley,
Panjim – Goa
Ans - <HTML>
<HEAD> </HEAD>
<BODY>
John Parera <BR>
&lt; H14 &gt; , Green Valley, <br>
Panjim – Goa
</BODY>
</HTML>
Q.61 – What is the difference between container tags & empty tags?
Ans – The container tags are pair tags i.e, they require a starting tag as well as an
ending tag. They affect the text appearing between the starting & ending tag.
The empty tags just require a starting tag and no ending tag. They just carry out the job
assigned to them.
Q.62 – What is the difference between <BASEFONT> and <FONT> tags?
Ans – The <BASEFONT> tag is used to define basic font size for the HTML page. Once
set, this font size is applicable to all the text following it, for which no other size has been
specified.
The <FONT> tag on the other hand, lets one define size, style and colour of a short
segment of text.
Q.63 – Write the name of HTML tag used to include an image in a HTML web page.
Ans - <img> tag.
Q.64 – Write HTML code for the following –
To provide hyperlink to a website http://www.e-school.com
Ans - <a href= “http://www.e-school.com”> Click here</a>
CHAPTER – 11 : HTML-2: LISTS, TABLES AND FORMS
Q.65 – Differentiate between <UL> and <OL> tags.
Ans – The <UL> tag is used for defining unordered lists. In these lists a special bullet
symbol appears in front of every list item.
The <OL> tag, on the other hand, is used for defining ordered or numbered lists. In
these links, a number or letter appears in front by every list item.
Q.66 – What are table sections? How can they be created?
Ans – A table comprises of one or more rows and header row. They may be many rows
focusing the table body and many rows depicting the table footer. If these are to be
rendered in different manners, table sections can be created. A table can be divided into
these sections :
1. Table header with <THEAD> tag
2. Table body with <TBODY> tag
3. Table footer with <TFOOT> tag
Q.67 – What is the similarity and difference between Text box control and Text area
control?
Ans – Both these controls are used for entering text. The difference between them is
that the textbox allows only one line, the text area, however, is much larger and allows
for as many word as the web page author wants.
Q.68 – What is the difference between radio button and checkbox control?
Ans - With radio buttons, only one radio button out of many choices can be selected,
whereas many checkboxes can be selected as desired.
CHAPTER – 12 : XML – eXtensible Markup Language
Q.69 – What is markup language?
Ans – A markup language is a set of rules/ tags that define the structure and format of
text while presenting text.
Q.70 – Compare HTML and XML.
Ans –
S.No.
HTML
XML
1
HTML document formats
XML documents carry data along with their
and displays web pages’ data. description.
2
HTML tags are pre-defined.
XML tags are not pre-defined. New tags can
be created and defined as per the need.
3
HTML tags may not have
XML tags must have a closing tag.
closing tag.
4
HTML tags are not case
XML tags are case sensitive.
sensitive.
5
HTML documents are
XML documents can be viewed only if proper
directly viewable in a
CSS/XSL file is also available along with XML
browser.
file.
Q.71 – What are the components of an XML file in terms of logical structure?
Ans – An XML file contains –
1. Prolog, which is an introduction to XML document. The grammar structure of
the XML document is defined under prolog.
2. Data instance, which consists of real data and its description through elements.
It is also known as body of XML document.
Q.72 – What is root element?
Ans – The parent element of all other elements in data instance is known as root
element or document element.
Q.73 – What is declared empty tag?
Ans – A declared empty element tag is a tag without end tag. It is written as the
tagname with a following slash e.g. <etag/> can be written in place of writing - <etag>
</etag>.
CHAPTER – 13 : MySQL REVISION TOUR
Q.74 - What are DDL and DML?
Ans: The DDL provides statements for the creation and deletion of tables and indexes.
The DML provides statements to enter, update, delete data and perform complex
queries on these tables.
Q. 75. Given the following tables for a database LIBRARY:
Table: Books
Book_Id Book_Name
Author_Name
F001
The tears
William Hopkins First Publ
750
Fiction
10
F002
Thunderbolts
Anna Roberts
First Publ
700
Fiction
5
T001
My First C++
Brian & Brooke
EPB
250
Text
10
T002
C++ Brainworks A.W.Rossaine
TDH
325
Text
5
C001
Fast Cook
EPB
350
Cookery 8
Lata Kapoor
Publishers Price Type
Table: Issued
Book_Id
Quantity _Issued
F001
3
Qty
T001
1
C001
5
Write SQL queries for (a) to (f):
a. To show Book name, Author Name, and Price of books of EPB publishers.
b. To list the names of books of fiction type.
c. To display the names and price of the books in descending order of their
price.
d. To increase the price of al books of first publ by 50.
e. To display the Book_Id, Book_Name, and Quantity_Issued for all books
which have been issued.
f. To insert a new row in the table Issued having the following data: “F002”, 4.
g. Give the output of the following queries based on the above tables:
1. SELECT COUNT (DISTINCT Publishers) FROM Books.
2. SELECT SUM (Price) FROM Books WHERE Quantity>5
3. SELECT Book_Name, Author_Name FROM Books WHERE
Price<500
4. SELECT COUNT (*) FROM Books.
Ans:
i.
ii.
iii.
iv.
v.
vi.
vii.
SELECT Book_Name, Author_Name, Price
FROM Books WHERE Publishers = “EPB”;
SELECT Book_Name FROM Books WHERE Type = “Fiction”;
SELECT Book_Name, Price FROM Books ORDER BY Price DESC;
UPDATE Book SET Price = Price + 50 WHERE Publishers = “First Publ”;
SELECT Books.Book_Id, Book_Name, Quantity_Issued FROM Books,
Issued WHERE Books.Book_Id = Issued.Book_Id;
INSERT INTO issued VALUES(“F002”, 4);
i) 3
ii) 1350
iii) My First C++ Brian & Brooke
C++ Brainworks A.W.Rossaine
Fast Cook Lata Kapoor
iv) 5
CHAPTER – 14 : DATABASE TRANSACTIONS
Q.76 – What do you understand by transaction COMMIT & ROLLBACK?
Ans – Committing a transaction means all the steps of a transaction are carried out
successfully and all data changes are made permanent in the database. Transaction
rollback means transaction has not been finished completely and hence all data changes
made by the transaction in the database, if any, are undone and the database returns to
the same state as it was before this transaction execution started.
Q.77 – What are important transaction properties?
Ans – To ensure the data-integrity, the database systems maintain the following
properties of transactions, also known as ACID properties –
1. Atomicity – It ensures that either all or none operations of a transaction are
carried out.
2. Consistency – It ensures that the database remains in a consistent state before
the start of transaction and after the transaction is over.
3. Isolation – It ensures that each executing transaction execution is isolation.
4. Durability – It ensures that after the successful completion of a transaction, the
changes made by it to the database persist.
Q.78 – What is the difference between COMMIT & ROLLBACK commands of MySQL?
Ans – Commit command explicitly ends the transaction and stores the changes
permanently in the database. Whereas, ROLLBACK command explicitly ends the
running transaction and undoes the changes in data.
CHAPTER – 15 : MORE ON SQL – GROUPING RECORDS & TABLE JOINS
Q.79 – What is the significance of GROUP BY clause in SQL query?
Ans – The GROUP BY clause combines all those records that have identical values in a
particular field or group of fields.
Q.80 – What is the difference between a WHERE clause and a HAVING clause of SQL
SELECT statement?
Ans – The difference between WHERE and HAVING clause is that WHERE conditions
are applicable on individual rows whereas HAVING conditions are applicable on groups
are formed by GROUP BY clause.
Q.81 – Write a query to display the sum, average, highest and lowest salary of the
employees department-wise.
Ans – select sum(sal), avg(sal), max(sal), min(sal) from emp group by deptno;
Q.82 - Write a query to display the sum, average, highest and lowest salary of the
employees department-wise and sub grouped by job.
Ans – select sum(sal), avg(sal), max(sal), min(sal) from emp group by deptno, job;
Q.83 – Write a query to display the number of employees with same job.
Ans – select count(*) “No_emps”, job from emp group by job;
Q.84 – Write a query to display the difference of highest and lowest salary of each
department having maximum salary greater than 4000.
Ans – select max(sal) – min(sal) frm emp group by deptno having max(sal) > 4000;
Q.85 – A table transport in a database has degree 3 and cardinality 8. What is the
number of rows and columns in it?
Ans – No. of rows = 8
No. of columns = 3
CHAPTER – 16 : TABLES AND INTEGRITY CONSTRAINTS
Q.86 – What do you understand by constraint? What is their significance?
Ans –A constraint is a property assigned to a column or set of columns in a table that
prevents certain types of inconsistent data values from being placed in the columns.
Constraints are used to enforce the data integrity.
Q.87 – What is Primary key constraint?
Ans – A primary key constraint is a unique identifier for a row within a database table.
Every table should have a primary key constraint to uniquely identify each row and only
one primary key constraint can be created for each table.
Q.88 – What is Foreign key constraint?
Ans – A foreign key constraint prevents any actions that would destroy link between
tables with the corresponding data values. A foreign key in one table points to a primary
key or a unique key in another table. A table can have multiple foreign keys.
Q.89 – What is the significance of NOT NULL constraint?
Ans – A Not Null constraint enforces that the column will not accept null values. The
Not null constraints are used to enforce domain integrity.
Q.90 – What does the NO ACTION attribute do in foreign key attribute?
Ans – ON DELETE NO ACTION – specifies that if an attempt is made to delete a row
with a key referenced by foreign keys in existing rows in other tables, an error is raised
and the DELETE is rolled back.
ON UPDATE NO ACTION – specifies that if an attempt is made to update a key value in
a row whose key is referenced by foreign keys in existing rows in other tables, an error is
raised and the UPDATE is rolled back.
Q.91 – When a Primary key constraint is included in a table, what other constraints
does this imply?
Ans – Two more constraints implies along with primary key constraint. They are
UNIQUE and NOT NULL.
CHAPTER – 17 : IT APPLICATIONS
Q.92 – How has e-governance benefitted the common man?
Ans – e-governance has benefitted the common man in following ways –
1. The number of trips to government offices reduced by nearly 11% to 27%.
2. Waiting time reduced from 10 % to 60%.
3. Bribes reduced by 50% to 90%.
4. All above factors resulted in reduced cost of availing the service.
Q.93 – What benefits does an e-business offer to the customers?
Ans – For customers, e-business offers the following benefits –
1. Improved speed of response.
2. Cost savings.
3. Improved efficiency and productivity.
4. Improved customer service.
Q.94 – what do you think is the most outstanding feature of e-learning?
Ans – The most outstanding feature of e-learning is that it has opened door for skill
enhancement to the people of all age groups, people of ll skill levels and people
belonging to different strata of society.
Q.95 – What is the significance of a good GUI?
Ans – A good GUI design is an important feature for a software’s success and
acceptance. If the end users find the software to be too difficult to understand, then the
software may be rejected even if it is an excellent software product.
Q.96 – What features are expected from an effective front-end?
Ans – Following features may be suggested for an effective front-end –
1. Ease of use i.e. user-friendly
2. Conventional use of words and terms
3.
4.
5.
6.
Simple look
Easy to understand
Proper visual feedback
Availability of proper help and guidance
Q.97 – Define front-end of an information system.
Ans – This is the user interface that the user sees and which is responsible for
interacting with the user. The front-end is responsible for receiving user’s queries,
requests etc. and passing it over to the back-end. The front-end includes GUI and the
input forms, through which user interacts with the system.
Q.98 – What do you understand by Back-end of an information system?
Ans – Back-end is that part of the application that does the real processing work or gets
it done from the server. It, infact, is responsible for processing data for user queries and
requests.
Q.99 – What societal impact does e-Governance has on society?
Ans – e-Governance has helped citizens in the following ways –
1. The number of trips to government offices reduced by nearly 11% to 27%.
2. Waiting time reduced from 10 % to 60%.
3. Bribes reduced by 50% to 90%.
4. All above factors resulted in reduced cost of availing the service.
Q.100 – What are the advantages of e-business sites?
Ans – e-Business offers benefits, such as –
1. Improved speed of response.
2. Cost savings
3. Improved efficiency and productivity
4. Improved customer service
Q.101 – What is the impact of e-Learning websites on students’ learning process?
Ans – The impacts of e-Learning sites are –
1. Availability of same course to millions.
2. Boon for working class.
3. Apprehensive employers
4. High drop-out rate
5. Cultural differences obstruct the true aim of e-learning.
Q.101 – Write two important features of e-business. Name two most commonly used eBusiness sites.
Ans – Two important features of e-Business sites are –
1. e-Business allows companies to link their internal and externally processes more
efficiently and effectively.
2. e-Business works beyond boundaries of bricks, cities and nations.
Two common e-Business sites are –
1. www.amazon.com
2. www.yatra.com