Class 8 Computer

Discover the world of computer science in our comprehensive class 8 computer course. Explore essential topics including hardware, software, programming fundamentals, internet safety, and more. Develop practical skills through hands-on activities and engaging lessons designed to build a strong foundation in computer literacy. Join us to unlock the exciting possibilities of technology and prepare for a digital future with our class 8 computer curriculum.

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Chapter 1 Concept of Networking

Answer the following questions (Class 8 Computer):

Question 1 What is the importance of a network?

Answer: A network is a collection of computers which are connected to each other to share information and resources. One of the best examples of network is Internet which connects millions of computers all over the world. The importance of network is given below:

Effective Backup: Copies of the important files can be made and saved on another networked computer or the server. If one system crashes due to any reason, the data will not be lost. In fact, the data can be retrieved from the backup.

Effective means of communication: Through computer network, people can communicate with each other by sending and receiving text messages, voice messages or video calls. So it provides a cheap and quick communication.

Effective Security Measures: The security of a network is managed through passwords and user names. It is easier to protect the important data when it is saved at one place.

Question 2 Explain the different components of a network ?

Answer : The various components of a network are :

(a) NIC (Network Interface Card): Every computer on a network has a NIC. It is a hardware device which is used to join the network cable to the computer.

(b) Communication Media: Two types of communication media are used:

• Wired
• Wireless

1. Wired Media: Wired media are the electric cables used to carry the signals from one end to another. Example: Fiber optical cable, Coaxial cable
2. Wireless Media: Wireless media do not require cables to transmit signals. Signals are transmitted through Bluetooth, Infrared, Microwave or Radio wave.

(c) Hub/Switch: These devices are used to connect a number of computers together to make a network.

(d) Modem: It is used to connect digital computer to analog telephone line. It converts digital signals to analog and vice versa.

Question 3 Differentiate between wired and wireless network?

Answer : The difference between Wired and Wireless Network are:

1. It uses physical mode for communication which consists of cables.	It does not use cables for communication. It is made up of electromagnetic waves or infrared waves.
2. The speed of operation is higher.	The speed of operation is lower. But the advanced wireless technologies have achieved speed par equivalent to wired network.
3. The system bandwidth is high.	The system bandwidth is low.
4. The cost of wired technology is less because cables are not expensive.	The cost of wireless technology is high because it needs wireless routers, access points, subscriber stations and adapters which are expensive.
5. The installation of wired network is cumbersome and requires more time.	The installation of wireless network is easy and requires less time.

Question 4 Explain the types of topologies that a network can use.

Answer : A topology is the format of the arrangements of computers in a network. The various types of topologies used in network are:

1. Bus Topology: In this topology, the various computers or devices are connected to each other through a single cable known as backbone. Each signal passed is received by all the nodes but only the destination node is able to use it.
2. Star Topology: In this topology, all the computers are connected to a central hub/switch using separate wires. Each signal passed to the central computer before reaching to the destination node.
3. Ring Topology: In this topology, all the computers are connected to each other using links in the form of loop. A token goes around the loop continuously, which is used to send or receive the message in a loop.
4. Tree Topology: This is a combination of Bus and Star topology. It can have multiple servers. These servers are interconnected so that a user may access his own server when required. It shows parent-child relationship.

Chapter 2 Log ON to MS Access

Answer the following questions (Class 8 Computer):

Question 1 Describe the various components of MS Access window?

Answer : The various components of MS Access window are :

• Title Bar: It displays the name of currently opened window.

• File tab: It displays the various options of File commands like New, Open etc.

• Quick Access Toolbar: It displays quick access buttons like Save, Undo, Redo etc.

• Database Object: There are four main database objects – tables, queries, forms and reports.

• Navigation Pane: It contains all database objects.

Question 2 What is a database? Explain the advantages of using database.

Answer: Database is a collection of information that is organized so that it can be easily accessed, managed and updated. The various advantages of using database are :

• Reduced Data Redundancy: The data redundancy is removed when you store the data in database with the proper use of foreign key.
• Minimum data inconsistency: It also helps in minimizing data inconsistency.
• Improvement in data integrity: Authorized users are generally restricted to particular data which they can access.

Question 3 How can you create a blank database?

Answer : A blank database consists of single blank table. After creating a database, you can add more tables, forms, reports etc to it. To create a blank database,

• Click on File tab.
• Select Blank database option.
• Specify the name for a new database in File Name text box.
• Click Create button.

Question 4 How will you create a new table in Design View?

Answer: To create a new table in Design view,

• Open a database and click on Create tab in ribbon.
• Select Design tab from Table Tools.
• In the Field Name column, enter the name of the first field and press tab key to move to next Data Type column.
• Select the data type of the field. You can modify the properties of the selected data type in lower pane.
• Press tab key and add Description for the field in Description column.
• Repeat the same procedure and enter the fields of the table with data type and description.

Question 5 What are the various steps to add records to a table?

Answer: Steps to add records to the table are:

• Double click on the table name in Database window.
• Type the data under first field and press tab to move to next field.
• Type the data and repeat the same step to enter the data for all the fields of first record.
• Press enter key to move to next line to make the entries for next record.
• After you complete entering data, press Save button to save the changes.

Question 6 Describe the Field properties?

Answer: The various field properties are:

• Properties Pane: It displays the various properties of the field when it is selected in Design view.
• General tab: It comprises most of the properties you work with.
• Lookup Table: It is mainly used for setting up lookup lists.
• Property information: When the insertion point is in property’s box, information about that property displays here.
• Yes/No Properties: Some properties illustrate yes/no questions.

Question 7 What are Data Types? List and explain the various data types available in Access 2016?

Answer : Data type is used to specify the type of data that a field can contain. The various data types used in MS Access are:

• Text: It is used to enter alpha-numeric characters, which can be up to 255 characters.
• Memo: It is used for detailed, descriptive fields and can limit up to 653,999 characters.
• Number: It is used to store numeric data.
• Date/Time: It is used to store date and time values.
• Currency: it is used to store monetary values.
• Auto Number: It is used to store a sequential number for each record automatically.
• Yes/No: The value 1 represents Yes and O represents No.
• OLE object: It is used to store objects created in another application.
• Attachment: It is used to attach data files like word processing software or spreadsheet etc.

Chapter 3 More Features of MS Access

Answer the following questions (Class 8 Computer):

Question 1 What do you know about find and replace command in Access?

Answer : Find command is used to search for a particular record in tables, queries and form quickly. Replace option is used to replace the searched filed with another field.

Steps to using Find and Replace command are:

• Open a table in Access and select the field that you want to search.
• Click on Home> Find group> Find option.
• A Find and Replace dialog box appears.
• In Find What text box, type the search string.
• The Look In list displays the name of the field you have selected.
• If you want to search the entire table, select the table name.
• Match list provides the options to select any one match type.
• It provides broadest possible search.
• Search list allows you to search up or down from the insertion point or search the whole document.
• Click on Replace tab.
• Click on Replace All button if you want to replace all the searched words in a document.
• Click on Replace button if you want to replace only the selected text.

Question 2 How will you sort records? Give examples.

Answer : Sorting means to arrange the records in ascending or descending order. Steps to sort the records of a table are:

• Open the table and click on the column header of the field that is to be sorted.
• Click on Home tab.
• From Sort & Filter group, select Ascending option if you want to sort the records in ascending order or Descending option if you want to sort the records in descending order.
• You will get the sorted records

Question 3 Write the steps to filter data using Filter by form.

Answer : Filter means to retrieve only the required data from the database and not the entire database. It enables you to review and analyze information in database.

Steps to Filter data by form are :

• Open a table.
• Click on Home tab.
• From Sort & Filter group, select Advanced> Filter by Form option.
• Select the filed and value to be used as criteria in Filter by Form window.
• It will display only the records that matches the criteria.

Question 4 How AND is different from OR criteria statement?

Answer : AND and OR are used to define more than one criterion while filtering the records from table. But AND criteria is different from OR criteria. AND criteria is used to find the records where all the conditions are met, whereas OR is used to find the records where at least one condition is met.

Question 5 How can you change your table view? Give example.

Answer : We can view the table in Datasheet View or Design View. Datasheet view is used to enter data and Design view is used to modify table design.

• Change the view of a table to Design View:
  • Click on Home tab.
  • From Views group, click on View drop-down arrow.
  • Select Design View.
  • The design of the table displays with field properties.

• Change the view of a table to Datasheet View:
  • Click on Home tab.
  • Select Datasheet View.
  • It will display the datasheet view of table.

Question 6 Write down the steps to create forms using wizard.

Answer : Steps to create form using wizard are:

• Click on Create tab.
• From Forms group, select Form Wizard option.
• A Form Wizard opens.
• Select the table from Tables/ Queries drop-down list.
• Double click on the fields from Available Fields area to add it to Selected Fields box.
• Click on Next button.
• From the next wizard, select the layout for the form and click Next button.
• We Enter the name of our Form and click on Finish button.

Chapter 4 Working With Queries/Forms/Reports

Answer the following questions (Class 8 Computer):

Question 1 What do you know about criteria?

Answer : Criteria helps us to retrieve specific items from an Access database. If an item matches with all the criteria you enter, it appears in the query results. When you want to limit the results of a query based on the values in a field, we use query criteria.

Some important topics related to Criteria is given by :

• A query criterion is an expression that Access compares to query field values to determine whether to include the record that contains each value.
• Some criteria are simple, and use basic operators and constants. Others are complex, and use functions, special operators, and include field references.
• To add some criteria to a query, we must open the query in the Design View.
• We then identify the fields for which you want to specify criteria.

Question 2 Why is the important to create relationship between tables?

Answer : In MS Access, data is stored in multiple tables. To bring that information together, you need to create relationship among those tables. Once a relationship is defined among the tables, the data from those tables can be used by Query, Forms or Reports.

Relationship are links that relate a field in one table with the same field in another table. Generally, it is the primary key in one table and a foreign key in another table.

Question 3 How can you make a query in Query wizard?

Answer : To create a query in Query Wizard, follow the given steps :

• Click on Create tab.
• From Queries group, select Query Wizard option.
• A New Query dialog box opens.
• Select Simple Query Wizard option and click OK button.
• A Simple Query Wizard opens.
• Select the table from Tables/ Queries list box.
• Add the fields that you want to have in query list.
• That will be added to Selected Fields box.
• Click Next button.
• Choose the type of query like Summery Query or Detail Query.
• Click Next button. Type the name of the query. Click Finish button.

Question 4 What is a Form? How can you format a form using Design tab?

Answer : In MS Access, Form is used to add and update data in one record at a time in a table. It is just like a normal form like an admission form or Feedback form. It is used to create a user-friendly interface. We can modify the look of the form by applying various options using Design tab. For this-

• Click on Logo in Header/Footer group of Design tab.
• An Insert picture dialog box opens.
• Select a picture and click OK button.
• Click on Title option and give a title for a form.
• Click on Date and time option to choose the required format for date and time.
• Click OK button.
• Click on Themes in Themes group and select the desired theme from available options.

Question 5 How can you export a Report to a Word file?

Answer : To export a report to a Word file :

• Click on Home tab.
• From Views group, select View drop-down button.
• Select Print Preview option. The report will open in Print Preview layout.
• Go to Data group and click on More drop-down arrow and select Word.
• The Export-RTF File dialog box opens.
• Select the location where we want to save the report and give a suitable to the report.
• Click OK.

Question 6 How can you create a Query in Design view?

Answer : To create a query in Design View :

• Click on Create tab. From Queries group, select Query Design option.
• A Show Table dialog box appears.
• Select the record source for a query which can be one or more tables or queries or both.
• Click Add button and close the dialog box.
• The selected table will emerge as a small window in the upper section of the Objects Relationships Pane.
• The selected query table shows a list of fields.
• Double click on field names which you want to add in query.
• That will be added to Design grid.
• When we run the query, it will display the selected fields of the selected tables or queries to us.

Question 7 What is the difference between a Form and Report?

Answer : The difference between Forms and Reports are:

Form	Report
A form is used to gather the information for essentially one record of database.	Report is used to represent information gathered from more than one file.
Forms are used for input to the system.	Reports are used for output from the system.
Values in the forms can be entered and modified by the user.	Values in the reports cannot be entered or modified by the user because reports are read-only.
Forms are intended for displaying on the screen.	Reports are intended for printing.

Question 8 Write steps to create a report in Access.

Answer : To create a Report in Access :

• Open the Navigation Pane.
• Click on table or query on which you want to base a report.
• Click on Create tab.From Reports group, select Report option.
• A new report is created and all the fields are of the selected table are placed in the report.
• We can modify the report using the specific options in the related tabs in ribbon like Design, Arrange, Format and Page Setup.
• To save the report, click on Save option from Quick Access toolbar.
• The Report will get added to Navigation Pane

Chapter 5 Using Lists and Tables in HTML 5

Answer the following questions (Class 8 Computer):

Question 1 What is Nested list ? How is it different from Ordered or Unordered list? Give an example of nested list.

Answer : A nested list is a multilevel list in which we create a list inside another list. An ordered list is a list which marks the list items with numbers. An unordered list is a list which marks the list items with bullets. An ordered or unordered list is a simple list and not a multilevel list. When we create an ordered list within another ordered list or unordered list within unordered list or ordered list within unordered list, that means we are creating a nested list.

For example:

• List of Computer Devices
  • Input Devices
    • Keyboard               
    • Mouse
  • Output Devices
    • Monitor                         
    • Printer
  • Storage Devices
    • Hard Disk                     
    • Pen Drive

Question 2 What are the various types of list supported by HTML5? Describe each one of them briefly.

Answer : A list is the most effective way of producing information in precise manner. It enables in making important points stand-out more clearly, and grabbing viewer’s attention. HTML supports three types of lists:

1. Unordered List
2. Ordered List
3. Description List

1.Unordered List: This list is used to incorporate a bullet against each of the item in a list. It starts with <ul> tag and ends with </ul> tag. It is also called Bulleted list.

Example: Types of network topologies:

• Bus Topology
• Star Topology
• Tree Topology
• Ring Topology

2.Ordered List: This list is used to incorporate a number against each of the item in a list. It starts with <ol> and ends with </ol> tags. It is also called Numbered List.

Example: Types of Network are:

1. LAN
2. WAN
3. MAN

3.Description List: This list consists of a term and its definition, just like glossary. It starts with <di> and ends with </di> tag. The <dt> tag is used to specify definition term and <dd> tag for definition description. Both are container tags.

• <dt> helps in specifying the terms or names called data terms.
• <dd> helps in explaining each term or name, called data definition.

Example:

• DNA : DNA is a short form of Deoxyribonucleic acid
• RNA : RNA is a short form of Ribonucleic acid

Question 3 What do you understand by tables and how are they created in HTMLS?

Answer : A table is used to present the information in the form of rows and columns. To create a table in HTML, we use <table> tag which is a container tag. <tr> is used to define table row. <th> is used to define table heading and <td> is used to define table data.

Example :

To create a table in HTML, you use the <table> element along with several other supporting elements. Here’s a step-by-step guide on how to create a simple table:

1. Start by using the element to define the beginning of the table:

<table>
  <!-- table content goes here -->
</table>

2. Inside the element, you define the table rows using the element. Each row will contain the table data cells:

<table>
  <tr>
    <!-- table data cells go here -->
  </tr>
  <tr>
    <!-- another row -->
  </tr>
  <!-- more rows if needed -->
</table>

3. Within each <tr> element, you define the table data cells using the <td> element. These cells will hold the actual data:

<table>
  <tr>
    <td>Row 1, Cell 1</td>
    <td>Row 1, Cell 2</td>
  </tr>
  <tr>
    <td>Row 2, Cell 1</td>
    <td>Row 2, Cell 2</td>
  </tr>
</table>

4. Optionally, you can use the element instead of to create table header cells. These cells are typically used to label the columns or provide additional information:

<table>
  <tr>
    <th>Column 1</th>
    <th>Column 2</th>
  </tr>
  <tr>
    <td>Data 1</td>
    <td>Data 2</td>
  </tr>
</table>

5. You can also span cells across multiple rows or columns using the colspan and rowspan attributes:

<table>
  <tr>
    <td rowspan="2">Spanned Cell</td>
    <td>Row 1, Cell 2</td>
  </tr>
  <tr>
    <td>Row 2, Cell 2</td>
  </tr>
</table>

Structure of Table will be like this

Start by using the element to define the beginning of the table:

Inside the element, you define the table rows using the element. Each row will contain the table data cells:

Within each element, you define the table data cells using the element. These cells will hold the actual data:

Row 1, Cell 1	Row 1, Cell 2
Row 2, Cell 1	Row 2, Cell 2

Optionally, you can use the element instead of to create table header cells. These cells are typically used to label the columns or provide additional information:

Column 1	Column 2
Data 1	Data 2

You can also span cells across multiple rows or columns using the colspan and rowspan attributes:

Spanned Cell	Row 1, Cell 2
	Row 2, Cell 2

Question 4 Write short notes on List-styles-image and Empty-cells.

Answer : List-style-image: List-style-image is a list property which is used to define an image as the list item marker. The value assigned to this property must be the complete path of where the image resides in the system. You can also define its value as None.

Syntax: list-style-image: value

Empty-cells: Empty-cells is a table property which is used to define whether or not the border and background are to be put around empty cells in a table. For this, we need to specify the value which can be show if you want to show the border or background or hide if we do not want to show the border or background around the empty cells.

Syntax: empty-cells: show/hide

Question 5 Explain the various table properties in detail.

Answer : The various table properties are:

• Border: The Border property is used to define the border width, border style and border color of the table and its cells.

Syntax: border:value

• Hover: It is used to highlight table cells, row or column with defined color, when you hover a mouse over it.

Syntax: element:hover{property}

• Table Layout: This property is used to set the layout of the table.

Syntax:  table-layout: autoIfixedIinitial

• Border-spacing:This property is used to define the space between the borders of adjoining cells.

Syntax: border-spacing:value in pixel or cm

• Height and width: This property is used to define the height and width of the table.

Syntax: height: value in pixel or cm or% Width: value in pixel or cm or %

• Padding: This property is used to define the space between the border and contents of a table.

Syntax: padding: value in pixel or cm or %

Question 6 What is the purpose of Description List?

Answer : Description list is used to create a list which consits of term and its description. It is just like a glossary in which the terms are defined through their description. This list begins with <di> and ends with </di>. The data terms are defined by using <dt> and </dt> tags. The data descriptions are defined using <dd> and </dd> tags.

For example:

• Input Devices : Input devices are those devices which are used to enter data into the computer like keyboard and mouse.

• Output Devices : Output devices are those devices which are used to produce the output either in the form of hardcopy or softcopy. Example: Monitor and Printer.
• Storage Devices : Storage devices are those devices which are used to store the data like hard disk, CD or Pen drive.

Chapter 6 Images, Links & Frames in HTML 5

Answer the following questions (Class 8 Computer):

Question 1 How images are inserted in an HTML document? What are the various attributes of an image element?

Answer : Image is inserted to an HTML document by using <img> tag. It is an empty tag which does not has an ending tag. src is a mandatory attribute used with <img> tag.

Syntax: <imgsrc=”Complete path of an image”>

The various attributes of <img> tag are:

• Height: height attribute is used to define the height of an image in pixels or percentage.
• Weight: weight attribute is used to define the width of an image in pixels or percentage.
• Float: This attribute is used to align an image to the left or right of the text.
• Alt: This attribute is used to display the alternative text in case image is not displayed in a web page due to any reason.

Question 2 What is the significance of associating alternate text with an image?

Answer : Sometimes, a web browser does not support the particular format of an image and therefore, does not display the image when you open a web page. Another reason of not showing the image in web page can be slow connection or error in source attribute. In such case, you can display the alternative text using ALT attribute which will display in place of image when an image will not open. ALT attribute allows you define the text as an alternative to the image.

Syntax: <imagsrc = “URL” alt= “text’>

Question 3 How can we link webpages in HTML? What are the various types in linking?

Answer : A link or hyperlink is used to create a link between two webpages. When you click on this link, you will be directed to the linked page. There are two types of linking:

• Internal Linking
• External Linking

Internal Linking: When one part of the webpage is linked to another part of same webpage is called Internal Linking.

External Linking: When one part of the webpage is linked to another webpage is called external Linking.

To create a link in HTML, <a> tag is used. This is an anchor tag which has a mandatory attribute i.e. href. It is used to give reference to the linked page.

• Syntax:<a href= “value”> Text </a>
  • For example: <a href = “abed.html”> Click Here </a>

Question 4 Explain how audio and video clips can be inserted in an HTML document with the help of code.

Answer : The audio and video clips can be inserted in HTML document to grab the attention of the viewers and give a better understanding of the topic. To insert audio clip, we use <audio> tag which is a container tag and ends with </audio>. It supports format .mp3, .ogg, .wav etc. The video clip can be inserted using <video> tag which ends with </video> tag. It supports format .mp4, .webm etc.

To insert audio and video file in HTML document, the code is given below:

<html>

<head>

<title> Audio and Video Clips </title>

</head>

<body>

<h2 style= color:blue>An audio clip </h2>

<audio controls src="song.mp3">This is an audio file. </audio>

<h2> A Video clip</h2>

<video controls scr="video.mp4">This is a video file. </video>

</body>

</html>

Question 5 How Frames are useful? Explain.

Answer : Frames is used to organize the website by dividing the page into number of rectangular segments. All the segments are presented as independent windows within one browser window. This gives greater flexibility to design and maintain your site than simply dumping everything onto one page. You can make frames more interesting by adding site theme like image, logo etc. You add separate webpage in each frame. The frames can be created using <iframe> tag which is a container tag and ends with </iframe>tag.

Chapter 7 Introduction to JAVA

Answer the following questions (Class 8 Computer):

Question 1 Write a brief description on Java?

Answer : Java is a programming language which is used to create software for multiple platforms. This language was created by James Gosling from Sun Microsystems in 1991. It is an object-oriented programming language which provides features of inheritance, polymorphism and abstraction. When a Java program is compiled, the source code is converted into bytecode which can be executed on any platform. Java program access data both from local machines and the web and can be carried out on any platform that have Java-enabled Internet browser.

Question 2 What is object-oriented programming? Discuss its advantages.

Answer : Object-oriented programming is a methodology to design a program using classes and objects. A class is a collection of similar objects and an object is a real-world entity like pen, chair, table etc. In Object-oriented programming, a problem is viewed not as a sequence of steps to be done but as a collection of different objects that model the read world things. The fundamental idea behind Object-oriented programming is to store data and functions operating on that data into a single unit, called an object.

The advantages of Object-oriented programming are:

• The code can be reused and therefore, a programmer can save lot of his time during the development of application software.
• As the emphasis is on data rather than algorithms, a program can easily be broken down into objects which model truly real-world objects.
• The wrapping of data and function into same entity, which an be reused anywhere in the whole program.

Question 3 How do you develop programs in Java? Write the various steps.

Answer : To develop programs in Java, three steps needs to be followed:

Enter the Java Program: Java program is written using a text-editor like Notepad. For this,

• Click Start> All apps> Accessories> Notepad.
• A Notepad window opens. Type the Java program.
• Click on File> Save As. A Save As window opens.
• Specify the name in File name and save it with extension .java.
• Click on Save button.

Compiling Java Program: Java program is compiled at DOS prompt (Command prompt). For this,

• Click Start> All Programs> Accessories> Command prompt.
• In DOS prompt, change to the directory where the program is saved by typing DOS command (cd <folder name>).
• To compile the program, type javac<filename.extension>. The program will be compiled.

Running the Java Program: After a successful compilation, you can execute your Java program using the Java Virtual Machine (JVM). Run the following command: java <filename>.

Question 4 Explain the different data types of Java?

Answer : Data types are the types of data that can be used in a program. There are two kinds of data types in Java: Standard and Derived. Standard data type is also known as Primitive Data type and Derived data type is also known a Non-primitive or reference Data type.

The various standard data types are explained below:

• byte: Represents a 1-byte integer value.
• short: Represents a 2-byte integer value.
• int: Represents a 4-byte integer value.
• long: Represents an 8-byte integer value.
• float: Represents a 4-byte floating-point value.
• double: Represents an 8-byte floating-point value.
• boolean: Represents a boolean value (true or false).
• char: Represents a single character.

Non-Primitive Data Types:

• String: Represents a sequence of characters.
• Array: Represents a fixed-size collection of elements of the same type.
• Class: Represents a class or object type.
• Interface: Represents a contract for implementing classes.
• Enum: Represents a fixed set of named values.
• Object: Represents any Java object.

These data types have different sizes and ranges to accommodate various types of data. Primitive data types are the basic building blocks, while non-primitive data types are derived from the primitive types and provide more complex functionality.

Question 5 What are operations in Java? Explain each with examples.

Answer : Operators are the symbols used to carry out some operation. The various types of operators are:

1. Relational Operators: These operators are used to compare the values of two variables. The various types of relational operators are:

>	Greater Than	It is used to find whether the first number is greater than second.	A>B
<	Less Than	It is used to find whether the first number is less than second.	A<B
>=	Greater Than Equal To	It is used to find whether the first number is greater than or equal to second.	A>=B
<=	Less Than Equal To	It is used to find whether the first number is less than or equal to second.	A<=B
==	Equal to	It is used to find whether the first number is equal to second.	A== B
!=	Not equal to	It is used to find whether the two numbers are not equal.	A!=B

Arithmetic Operators: These operators are used to perform arithmetic operations. The various arithmetic operators are:

+	Addition	It is used	A+B
–	Subtraction	It is used to subtract two numbers.	A-B
*	Multiplication	It is used to multiply two numbers.	A*B
I	Division	It is used to divide two numbers.	A/B
%	Modulus	It is used to calculate the remainder on dividing two numbers.	A%B

Increment and Decrement operators:

• The increment operator is used to add 1 to the value of a variable.
  • For example: X++.
• The decrement operator is used to subtract 1 to the value of a variable.
  • For example: X–.

Logical Operators: Logical operators are used to find whether one or both the condition are true or false. The various logical operators are:

&&	Logical AND	The output of this operator is True if both the conditions are True.	(A>B)&&( B>C)
II	Logical OR	The output of this operator is True if any of the conditions are True.	(A>B)l l(B >C)
!	Logical NOT	It is used to find whether a condition is false.	!(A>B)

Question 6 Define the following terms.

• (a) Method
• (b) Class
• (c) Object

Answer : Definitions are given below:

(a) Method: A Java program is written by using classes and methods. The methods are defined inside the class body with the following syntax:

<access-specifier><return-type><method-name> ([argument-list]) Where,

• Access-specifier: defines whether the access is public or private
• Return-type: defines the data type of the value returned by the method
• Method-name: specifies the name of method
• Argument-list: specifies the various arguments

(b) class: A Java program is written by using classes and methods. A class is a collection of similar objects. A program begins with the class declared as public with class name. It begins and ends with curly braces {} as shown below:

public class classname { }

(c) Object: The fundamental idea behind Object Oriented Program (OOP) is to store the data and functions operating on that data into a single unit called an object. An object may represent a person, a student, an employee, an account, an examination or any item that closely resembles the objects of real world.

Question 7 Write the difference between for and while loop statements.

Answer : The difference between For and While loop are given below:

For Loop	While Loop
1. For definite loop when the number of iterations is known.	For indefinite loop when the number of iterations is unknown.
2. For loop can have its own counter variable declared inside the declaration itself.	There is no built-in loop control variable with a while loop.
3. In For loop, we know exactly how many times a loop will be executed.	The While loop will continue to run infinite number of times until the condition is met.
4. Syntax: for (initial­ value;condition;increment/dec rement value) { Statements}	Syntax: While(condition) { Statements}

Chapter 8 Windows Installation and Troubleshooting

Answer the following questions (Class 8 Computer):

Question 1 Describe about the troubleshooting.

Answer : Troubleshooting is the process of determining and resolving the problem related to computer hardware and/or software. It is a systematic approach to problem solving. The basic goal of troubleshooting is to identify a computer problem so that it can be fixed.

There are five types of troubleshooting:

• User Support: It involves problems which are created by users themselves like user have deleted some important files accidently from the system. A proper user training is needed to provide help in resolving such problems.
• Operating System Support: It involves problems related to installation, upgradation, configuration and maintenance of operating system. In such cases, you need to reinstall or repair the operating system.
• Hardware Support: It involves problems related to computer hardware. In such cases, you need the help of hardware engineers to resolve the problem.
• Software Support: It involves problems related to the installation and removal of application software. For this, you can take the help of software engineers to resolve the problem.
• Networking Support: It involves the problems related to the computer networks or internet. In such case, you need to troubleshoot your network.

Question 2 How will you install Windows 10 on your PC? Explain briefly.

Answer : To install Windows 10 in a PC,

• Insert a DVD or bootable Flash drive. The first screen appears.
• Choose the OS’ language, time, currency format and input method. Click Next button.
• Choose the media type like USB or ISO and click Next button.
• Click on Install Now button.
• Click on Custom: Install Windows only.
• Select the drive to install Windows 10 on. You can click on Format button and then OK button on warning message.
• When the drive format is complete, click Next button.
• Windows 10 installation begins. When it is almost complete, it asks you to enter the product key.
• Click on ‘Do this later’ and continue with setup process.

Question 3 What are the various types of installation?

Answer : There are two types of installation:

Upgrade Installation: In this type of installation, you simply start the installation inside the existing operating system. It recognizes that the operating system already exists and it upgrades it to the newest version. It also makes sure to keep all the applications and files in place the way they are.

Custom Installation: In this type of installation, you retain your existing files or system configuration setting and upgrade your existing Windows operating system by replacing the current windows files. It is an advanced type of installation.

Question 4 What are the basic steps of troubleshooting your PC?

Answer : The basic steps of troubleshooting a PC are:

Determine the problem: The first step is to analyze the nature of the problem like what type of message is displaying on screen, are you able to boot the PC and what is the reason of problem etc.

Categorize the problem: The problem can be categorized into one of the five types of support like User, Software, Hardware, Operating system and Networking.

Action Plan: You can decide whether you can resolve it yourself or need a technician. In this step, you can document your action plan and proceed further.

Implement the plan: The next step is to implement the plan. If the problem is in hardware components, you can replace it. If the problem is in software component, you can follow some basic guidelines to resolve the problem.

Run and Test the system: The last step is to operate the computer and test it properly to make sure that the problem has been resolved.

Question 5 What are the reasons to delete unwanted files in your PC?

Answer : It is very important to delete unwanted files from the computer system. If there is too much clutter on the hard drive, it not only consumes space but also makes it harder for the system to find files you need. For this, Windows has a built-in tool, known as Disk Cleanup which is used to remove the unrequired files.

To clean up the disk,

• Click on Start> File Explorer> Disk Cleanup.
• Right click on main hard drive (C: drive).
• Select Properties option from the pop-up list.
• It will display the list of files that can be removed.
• Select the category and click OK> Delete Files.

Chapter 9 Internet Application

Answer the following questions (Class 8 Computer):

Question 1 What do you mean by term Multimedia?

Answer : Multimedia is a term which is used to describe how multiple means of media like text, audio, video, graphics and animation are used to communicate the information. It is helpful in understanding the information at a faster way. Webpages often contain multimedia elements of different types and formats. The web has become a broadcast medium where one can listen to audio and enjoy video, both pre­ recorded and live.

The various examples of multimedia conveying information are: Newspaper, Television, radio, Internet.

Question 2 : What do you understand by RSS ?

Answer: RSS expands to Rich Site Summary or Really Simple Syndication. It is a type of web feed which allow a user to access updates to online content in a standardized format. RSS works by having the website author maintain a list of notification on the website in a specified way. This list is called RSS feed. Users can keep track of updates by simply checking the list. Each item in RSSS Feed consists of a simple title briefly describing the updated content along with a complete description and a link to a webpage having actual information. RSS Aggregations have been developed to access these feeds and organize the results for the users.

Question 3 : What is Skype? Mention any two basic requirements to use this Software.

Answer : Skype is an IP telephony service provider that offers free calling service. It includes telephone calls, file transfer, texting, video chat and video conferencing. A video call can be made which involves as many as 25 people at once using Group Video Call feature of Skype. Users can also share their computer screen with others using Group Screen Sharing feature. It provides translation in 8 languages for voice calls and more than 50 languages for instant messaging. The two basic requirements to use this software are:

• Fast Internet with sufficient bandwidth
• A speaker and microphone

Question 4 : What are the available tools of Real Time Communication?

Answer : Real Time communication is the text, audio and video communication that happen in real time on the web. It allows people to conference and collaborate in real time.The various tools used in real-time communication are:

• Chat : Sending text messages in real time.
• Audio : Conducting a telephone conversation on web.
• Video : Viewing your audience.
• File transfer : Sending files back and forth among participants.
• Document/ application sharing : Viewing and using a program on another’s desktop machine.

Question 5 : What do you understand by a Blog? Explain it’s use.

Answer: Blog is an online discussion or informational website displaying information in reverse chronological order. It is a platform where a writer can share his ideas and views on an individual subject. A person who posts his blogs is known as blogger. Reader’s can add comments to the blogger’s postings, and others can respond and a conversation ensues. Posts are typically displayed in reverse chronological order, so the most recent post appears first at the top of the webpage.

The various uses of blogs are:

• Blogs can be used as personal diary for people to share their personal experience, views, thoughts and contents.
• Blogs can be used to communicate the activities and events within the company.
• Blogs can be used by the businesses to engage with the audience at an informal level.
• It helps the bloggers to build a network of followers who are most likely to refer them to others.

Chapter 10 Creating Programs in Python

Answer the following questions (Class 8 Computer):

Question 1 What is IDLE Editor windows? Write steps to open it.

Answer : The IDLE editor in Python refers to the Integrated Development and Learning Environment, which provides a basic interactive development environment for Python programming. It is typically included with the Python installation on Windows.

Here are the steps to open IDLE Editor on Windows:

1. Install Python: If you haven’t already, download and install Python on your Windows system. You can download the latest version of Python from the official Python website (https://www.python.org/downloads/). Follow the installation instructions specific to your Windows version.
2. Open IDLE Editor:
   • Open the Start menu in Windows.
   • Type “IDLE” in the search bar.
   • Click on the “IDLE (Python GUI)” or similar option that appears in the search results.

Alternatively, you can directly open IDLE Editor by following these steps:

• Open the Start menu in Windows.
• Navigate to the Python folder in the program list.
• Inside the Python folder, you should find an option for “IDLE (Python GUI)”. Click on it to open IDLE Editor.

After following these steps, the IDLE Editor window should open, providing you with an interactive Python shell and a text editor for writing and executing Python code.

Question 2 What is the use of the print() function? Give example.

Answer : The print() function in Python is used to display output or information to the console or standard output. It allows you to print text, variables, or expressions for debugging, informational purposes, or user interaction.

Example:

name = “John”
age = 25
print(“Hello,”, name)
print(“Age:”, age)

Output:

Hello, John
Age: 25

In this example, the print() function is used to display a greeting message and the value of the age variable to the console.

Question 3 What is the use of the input() function? Give example.

Answer : The input() function in Python is used to accept user input from the keyboard during program execution. It allows the program to pause and wait for the user to enter data, which can then be stored in a variable or used for further processing.

Example:

name = input(“Enter your name: “)
print(“Hello, ” + name + “!”)

In this example, the program prompts the user to enter their name using the input() function. The user’s input is stored in the name variable. The program then prints a greeting message using the entered name.

Question 4 What is the use of the type() function? Give example.

Answer :

The type() function in Python is used to determine the type of an object or variable. It returns the class or type of the specified object.

Example:

x = 5
y = “Hello”
z = [1, 2, 3]

print(type(x)) # Output: <class ‘int’>
print(type(y)) # Output: <class ‘str’>
print(type(z)) # Output: <class ‘list’>

In this example, the type() function is used to determine the types of variables x, y, and z. It returns the corresponding class or type of each object, such as int, str, and list.

Question 5 What is the use of the int() function? Give example.

Answer : The int() function in Python is used to convert a value to an integer data type. It parses a string or a floating-point number and returns the corresponding integer value.

Example:

num_str = “10”
num_int = int(num_str)
print(num_int) # Output: 10

float_num = 3.14
int_num = int(float_num)
print(int_num) # Output: 3

In this example, the int() function is used to convert a string "10" to an integer value 10 and a floating-point number 3.14 to an integer value 3.

Question 6 What is the use of the float() function? Give example.

Answer : The float() function in Python is used to convert a value to a floating-point number (decimal number). It takes a numeric or string argument and returns a float representation of that value.

Example:

num = float(10)
print(num) # Output: 10.0

num_str = float(“3.14”)
print(num_str) # Output: 3.14

In the first example, the float() function is used to convert the integer value 10 to a floating-point number 10.0. In the second example, the float() function converts the string "3.14" to the corresponding float value 3.14.

Chapter 11 App Development

Answer the following questions (Class 8 Computer):

Question 1 : What are different types of apps? Explain with examples.

Answer : Apps can be divided into three main types on the basis of the platform or device they are used.

1. Desktop apps
2. Mobile apps
3. Web apps

Desktop apps  : Desktop application is a software program that can be run on a standalone computer to perform a specific task by an end-user. Some desktop applications such as word editor, photo editing app and media player allow you to perform different tasks while other such as gaming apps are developed purely for entertainment.

Some top examples of desktop applications are Microsoft Office, VLC Media Player, Windows File Explorer, and Activity Monitor on macOS, etc.

Mobile apps : A mobile app is a software application developed specifically for use on small, wireless computing devices, such as smartphones and tablets, rather than desktop or laptop computers. 

Some top examples of Mobile applications are WhatsApp, YouTube, Apple’s iTunes, Google Map Adobe Photoshop, Sketch etc.

Web apps : Apps that are designed to be used on the web (WWW) through an Internet connection are called Web apps. These apps can be accessed with the help of a web browser like Google Chrome, Internet Explorer, etc.

Google Docs, Google Sheets and PIXLR Photo Editor are some examples of web apps.

Question 2 : Differentiate between mobile apps and web apps.

Answer : Differentiate between mobile apps and web apps are given by:

• Mobile applications are specifically created to be operated from mobile. In contrast, web applications are created with the purpose of the content and services being browsed by the user from any device via browsers.
• Mobile applications need to be installed from the app store, while web applications can be easily viewed from any browser and thus do not need to be installed.
• Mobile applications can be accessed even offline, and that’s not the case with web applications since browsers do not work without a proper internet connection.
• Mobile applications are faster to browse, while web applications may take a while to load.
• Mobile applications need to be approved by the app store. Since web applications are browsed through browsers, they need not require approval from the app store.
• Mobile applications have more sophisticated security, while web applications may not have that level of heightened security compared to mobile applications.
• Mobile apps need to be updated frequently. Web apps will take care of updates themselves.

Question 3 : How are educational apps helpful to you? Give some examples of educational apps.

Answer : In these changing times, students are more driven towards using a mobile phone for every purpose. The world is at the fingertips and a student can get access to any information from anywhere. A mobile phone hence can be used for a number of such purposes. What makes the information easily available is mobile applications. Every mobile app has a unique feature which offers its own set of services.

Educational learning apps are designed to be engaging and enjoyable for students. Knowledge augmentation, tailored learning experiences, improved engagement, access to online study material, ease of communication, and, most significantly, remote access are all advantages of a learning app.

Examples of Educational Apps:

• Google Classroom.
• Khan Academy.
• edX.
• Sololearn.
• Photomath.
• Remind.
• BYJU’S- The Learning App
• e-Pathshala App
• Meritnation App

Question 4 : What are social networking apps? Give some examples.

Answer : The term social networking refers to the use of internet-based social media sites to stay connected with friends, family, colleagues, or customers. Social networking can have a social purpose, a business purpose, or both. Social networking is also a significant opportunity for marketers seeking to engage customers. Social networking is also a significant opportunity for marketers seeking to engage customers.

Some Examples of Social networking:

Question 5 : What is the use of digital wallet apps?

Answer : A digital wallet is a software-based system that allows individuals to make electronic transactions, such as bill payments, mobile recharges, and travel/movie bookings. Digital wallets can also be used to transfer money from one bank account to another.

A digital wallet app allows users to easily conduct a variety of transactions. Following are the some use of digital wallet apps

• Paying bills for electricity, gas, and mobile phone services
• Booking flights, train tickets, and other services
• Setting up alerts and enabling auto-payment options
• Transferring funds and adding money to the wallet
• Checking the balance and managing transactions.
• Foreign remittances under some guidelines
• Buy subscriptions
• etc..

Question 6 : How will you download an App from Google Play Store? Write in brief.

Answer :

• Open the Google Play Store app from the menu.
• Sign in with your Google account.
• Search applications– After signing in, you can search through different applications available on the Google Store, including games, music apps, etc.
• Install the app-Select the one that you want to download and press “Install.”
• Accept permissions-It will ask for your permissions, simply select “Accept.”
• Wait until the installation is complete- It depends on the size of the app. You will see a notification on your notification bar when the installation has been successful.
• Launch the app- That’s it! Now you can go to the menu and launch the downloaded app.

Question 7 : What does the Android Studio help you to do?

Answer : Android Studio is the official integrated development environment (IDE) for Android application development.

Android Studio provides a unified environment where you can build apps for Android phones, tablets, Android Wear, Android TV, and Android Auto. Structured code modules allow us to divide your project into units of functionality that you can independently build, test, and debug.

Chapter 12 Artificial Intelligence

Answer the following questions (Class 8 Computer):

Question 1 : What do you understand by Narrow AI? Explain with example.

Answer : Artificial Narrow Intelligence (ANI) also known as “Weak” AI is the AI that exist in our world today. ANI is designed to perform a narrow task, for instance, facial recognition, internet searches or just driving a car. Narrow AI’s machine intelligence is basically achieved through the concept of Natural Language Processing (NLP).

Examples of Narrow AI:

1. Virtual Assistants like Siri by Apple, Alexa by Amazon, Cortana by Microsoft, etc..
2. Rankbrain: It is an algorithm used by Google to sort the search results.
3. Self-Driven Cars.
4. Facial/Image recognition and interpretation software.
5. Social Media Marketing tools for keeping a check on violating contents and Email spam filters.
6. Manufacturing and Drone-based robots.

Question 2 : Write any two uses of Artificial Intelligence in daily life?

Answer : Every time we do a Google search, book a trip online, receive a product recommendation from Amazon, or open our Facebook newsfeed, which is just a few everyday instances – AI is working in the background. There are many application of AI in daily life. Some of them are listed here.

Maps and Directions : When apps like Google Maps calculate traffic and construction work in order to find the quickest route to our destination, That’s AI at work. Also Google Maps offers directions based on the fastest route according to the usual traffic.

Self-driving Vehicles : The technology of Autonomous Vehicle AI is witnessing large-scale innovation driven by global corporate interest. AI is making innovations beyond cruise-control and blind-spot detection to include fully autonomous capabilities.

Question 3 : Write about Personal assistants which work with AI. Name as many as you know.

Answer : Intelligent Personal Assistant, Automated Personal Assistant or Automated Virtual Personal Assistant can perform tasks, or services, on behalf of an individual bases on a combination of user input and location awareness. It has the ability to access information from a variety of online source such as weather conditions, traffic congestion, news, stock price, user schedules and retail prices.

Siri, Cortana, Alexa and Google Assistant etc. are the well-known examples of AI assistants that many developers integrate into their applications.

Question 4 : What is computer vision?

Answer : Computer vision is the field of computer science that focuses on creating digital systems that can process, analyze, and make sense of visual data (images or videos) in the same way that humans do. The concept of computer vision is based on teaching computers to process an image at a pixel level and understand it. Technically, machines attempt to retrieve visual information, handle it, and interpret results through special software algorithms.

Question 5 : What is Chatbot?

Answer : A chatbot is a computer program that simulates human conversation through voice commands or text chats or both. Chatbot, short for chatterbot, is an artificial intelligence (AI) feature that can be embedded and used through any major messaging application.

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See This Also

• Class 6 History
• Class 6 Civics
• Class 6 Geography
• Class 6 Computer
• Class 7 Computer