Informatics Practices 2014 CBSE [Delhi] Set I

(a) The E-Learning is an electronic learning system in which the learning is made easy with the help of digital content.

The www.extramarks.com is one of the popularly used website of e-learning.

(b) Electronic governance or e-governance is the application of information and communication technology (ICT) for delivering government services, exchange of information communication transactions, integration of various stand-alone systems and services.

By MCA-21 E-governance website, general public can get information regarding the registered companies; due to this facility public can identify fraud companies. Using e-governance facility the fake passport can be identified easily and passport department can control the crime using passports.

(c)

S.No	Operation	Control
1.	Enter Name of Employee	jTextField
2.	Select Department from a list of department names	jList
3.	Gender out of options M and F	jRadioButtons, ButtonGroup
4.	Submit form	jButton

(a) Advantages of networking computers instead of having standalone computers are-
i) In networking a user can log on to a computer anywhere on the network and access their work files from the file server whereas, the standalone computer does not provides this facility.
ii) In networking, computers can be managed centrally that result in faster installation of an application.

(b) Unicode is 16 bits encoding standard in which every character, digit, or symbol is assigned a unique numeric value that applies across different platforms and programs to support different languages and scripts.

(c)
(i) WAN- Wide Area Network
(ii) OSS- Open Source Software

(d) A Switch is a network device that works as a smart hub and is used to connect various computers over a network between two network devices.

(e) (i) Switch
(ii) Repeater

(f) In star topology each node is connected independently using a switch. The star topology reduces the chance of network failure by connecting all of the systems to a central node.

If the centralize device called switch/hub fails, the entire system is affected.

(g) A Denial of Service (DoS) attack is an attempt to make one or more network resources unavailable to their legitimate users.

Examples of such attacks are:
• Denial of Access to Information: Corrupting, Encrypting, or changing the status of information so that it is not accessible to its legitimate user.
• Denial of Access to Application: Forced shutting of an application as soon as the user opens it.
• Denial of Access to Resources: Blocking a resource, may be a printer or scanner or USB port, of a computer from proper working.
• Denial of Access to a Website: Continuously sending bulk requests to a website so that it is not available to any other user.

(a) The ‘/’ is used for dividing the operands whereas ‘%’ is used for computing the reminder of dividing operands.

(b) The ButtonGroup component manages the selected/unselected state for a set of buttons. For the group, the ButtonGroup instance guarantees that only one button can be selected at a time.
Initially, all buttons managed by a ButtonGroup instance are unselected.
The radio button controls are used with the button group object to make sure that only one radio button is selected at a time from the specified group.

(c) In Netbeans, the Model property of a ListBox control is used to display values in the List.

(d)
(i) The < font > tag of HTML is used to change the font in a page.
Example-
< font size="3" color="red" >This is some text!< /font >

(ii) The < tr > tag of HTML is used to add a row in a table.
Example-

< table border="1" style="width: 100%" >
< tr >
< td >Orange< /td >
< td >50< /td >
< /tr >
< /table >

(e) The variable sum will contain value 5 after the execution of the loop.
The variable sum1 will contain value 10 after the execution of the loop.

(f) The following value would be displayed in jTextArea1 after the execution of the loop: 10 20 30 40 50

(g) The HTML tags are divided into two types- Container tag and Empty tag.
The Container tags have both the opening tags and the closing tags whereas, the Empty tags are tags that contains only opening tag they do not have closing tags.

Example –

Container tag:

< html > is the opening tag
< /html > is the closing tag

Empty tag:

< img src="" > only opening tag
< br > only opening tag

(a) Two examples of DBMS softwares are- MySQL, PostgreSQL, Microsoft Access, SQL Server etc.

(b) In case when autocommit is set to ON, as soon as you execute a statement that updates (modifies) a table, MySQL stores the update on disk to make it permanent.

(c) The NULL in MySQL represents “a missing unknown value” and it is treated somewhat differently from other values.

(d) Cardinality of the Cartesian product of both the tables will be: 8

(e)
(i) SELECT ROUND(25565.7765,2);
(ii) SELECT ROUND(25565.7765);

(f)
(i) In Netbeans the setVisible() method is used to show or hide the control at run time.
The code jTextFiled1.setVisible(false); will hide the control during program run whereas code jTextFiled1.setVisible(true); will make the control visible during program run.
(ii) The method getSelectedValue() is used to return the selected item from the list. Example-

String value = (String) jList1.getSelectedValue();

(a) The NOW() function returns the current date and time whereas, the SYSDATE() function returns the time at which the function executes.

(b) The TRIM() function is used to remove leading and trailing spaces from a string.

(c)
(i) select Accountno, Name, DateOfopen

From SBOP

Where Transaction > 8;

(ii) select * from SBOP
Where Transaction Is NULL;

(iii) Alter Table SBOP
Add(size varchar(25));

(iv) Select Month(DateOfopen)
from SBOP;

(v)

count(*)

5

(vi)

Name	Balance
Mrs. Sakshi	45000

(vii)

Round(Balance,-3)

63000

 

(a) Create table SHOP( Fno integer(10) Primary Key, Fname varchar(15), Type char(10), Stock integer(3), Price decimal(8,2));

(b)
(i) select T.Tcode, T.Name, A.Aname
From TicketDetails T, AgentDetails A
Where T.Acode==A.Acode AND T.Tickets > 5;

(ii) select sum(T.Tickets)
From TicketDetails T, AgentDetails A
Where A.Aname=’ Mr. Ayush ’;

(iii) Select T.Tcode, T.Acode, A.AName
from TicketDetails T, AgentDetails A
where T.Tcode==A.Tcode AND A.Aname LIKE ‘ % k’;

(c) Tcode - Primary Key
The field Tcode is used to uniquely identify each field.
Acode- Foreign key
The field Acode has a link given with the same name in the child table as well.

 

(a) Inheritance is a capability/property of a class to inherit the properties of another class. The keyword extends is used to inherit the properties of the base class into derived class (child class).
The various types of inheritance are- Single level Inheritance, Multilevel Inheritance, Multiple Inheritance and Hierarchical inheritance and hybrid inheritance.
Java does not support Multiple Inheritance.

(b)

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

switch (choice)

{

case 1: jTextField2.setText(“January”);

                break;

case 2: jTextField2.setText(“February”);

                break;

case 3: jTextField2.setText(“March”);

                break;

case 4: jTextField2.setText(“April”);

                break;

                case 5: jTextField2.setText(“May”);

                break;

default: jTextField2.setText(“Only 1 to 5 please”);

              }

 

(c) Value of X1 after executing the code: PostGraduate

(d) The following code is used to make a jTextfiled1 un-editable during execution:

jTextfiled1.setEditable(false);

(e) The output will be: 9

(f) jTextField2=9

jTextField3=141

 

(g)

(i)

private void btnTotalActionPerformed(java.awt.event.ActionEvent evt) {

int English, Maths, Physics, Chemistry, Computers, Total;

English=Integer.parseInt(jTextField2.getText());

Maths=Integer.parseInt(jTextField3.getText());

Physics=Integer.parseInt(jTextField4.getText());

Chemistry=Integer.parseInt(jTextField5.getText());

Computers=Integer.parseInt(jTextField6.getText());

Total=English+Maths+Physics+Chemistry+Computers;

jTextField7.setText(Integer.toString(Total));

}

private void btnPercentageActionPerformed(java.awt.event.ActionEvent evt) {

int Percentage;

Percentage=(Integer.parseInt(jTextField7.getText())/5);

jTextField8.setText(Integer.toString(Percentage));

}

private void btnGradeActionPerformed(java.awt.event.ActionEvent evt) {

int per;

char Grade;

per=Integer.parseInt(jTextField8.getText());

if(per >= 90)

Grade='A';

else if(per >= 70 && per < 90)

Grade='B';

else if(per >= 50 && per < 70)

Grade='C';

else if(per >= 33 && per < 50)

Grade='D';

else

Grade='F';

jTextField9.setText(Character.toString(Grade));

}

(ii)

private void btnClearActionPerformed(java.awt.event.ActionEvent evt) {

jTextField1.setText(" ");

jTextField2.setText(" ");

jTextField3.setText(" ");

jTextField4.setText(" ");

jTextField5.setText(" ");

jTextField6.setText(" ");

jTextField7.setText(" ");

jTextField8.setText(" ");

jTextField9.setText(" ");

}

 

(iii)

private void btnExitActionPerformed(java.awt.event.ActionEvent evt) {

System.exit(0);

}