Computer book 4 layout final for ctp 2075 (1)

New

Gateway to
Computer Science

A Complete Text Book of Computer Science

Authors : Dinesh Adhikari, Dilendra Bhatta

Contributing Co-authors : LaxmanAdhikari,ShekharPoudel,
Toyaram Giri Arjun Poudel

Layout Design : Zeeta Computer Service Pvt. Ltd.

(Samin R. Dhungana) Ghantaghar,

Kathmandu, Nepal

Copyright © : Publisher

Edition : 2075

Publication : Shubharambha Publication Pvt. Ltd.
Kathmandu, Nepal

Preface Contents

Along with the evolution of human Unit
beings new thoughts, area of knowledge
and technology also developed together. 1. Introduction to Computer 1
Among the eruptions, ICT (Information
and Communication Technology) is 2. Importance of Computer 14
one which has unquestionably become
important part of human beings. A 3. Input Hardware 25
person is not better than a caged pigeon
if s/he is far from computer technology 4. Output Hardware 38
in this century. New Gateway to
Computer Science Book-4 is a 5.. Secondary Storage Devices 48
complete package which obviously
supports a lot to the students as this is 6. History of Computer 58
one of the most useful Text Book, so
far available in the market. This book 7. Operating System 70
is completely prepared considering the
level of the students. This text has the 8. Working With Paint 85
various salient features like it focus on
child psychology, inclusion of comic’s 9. Working With Word Pad 102
cartoons, conversation based, focus
on pictorial descriptions,quiz section, Quiz Section 118
worksheets, etc.
Work Sheets 122
Comments and constructive suggestions
are highly welcomed from the readers Model Question Paper 131
and professionals to update this text
book.

Suggest us:

[email protected]

Thank you.

Unit 1 Introduction to
Computer

Expected Competency
At the end of this unit, students will be able to,
¬¬ define the computer.
¬¬ tell about the hardware components.
¬¬ know the working principles of computer.
¬¬ tell about the characteristics of computer.
¬¬ discuss the limitations of computer.

Introduction to Computer 1

Introduction

Computers have touched every
part of our lives like the way we
work, the way we learn, the way
we live, even the way we play.
It is almost impossible to go
through a single day without a
device dependent on a computer
and information produced by a
computer. Because of the significance of computers in today’s
world, it is essential for everyone to have the knowledge of
computer. We must have the knowledge and understanding of
computers.

What is Computer?

Computer is an electronic device, which accepts data and
instructions as input and stores them on the memory to process.
After processing, it displays the desired output. Computers process
data to create information. Data is a collection of raw unprocessed
facts, figures, and symbols. Information is organized, meaningful,
and useful data. A computer uses hardware and software to process
data into information. Hardware is the physical equipment that
makes up a computer. Software is the collection of programs that
tells the hardware how to perform the tasks.

Why computer is a powerful tool?

A computer is a powerful tool because it is able to perform
input, process, output, and storage with a very high speed in a
few seconds. A computer is also more reliable and accurate. The

2 New Gateway to Computer Science Book 4

computer allows the user to generate correct information quickly,
store and share them with other computer users.

Quick Learn!

¬¬ A computer is an electronic device.
¬¬ The data is a collection of unprocessed facts.
¬¬ Hardware is the physical components of the computer.
¬¬ Software is a computer programs.
¬¬ Input and output devices are the computer hardwares.
¬¬ Input is the act of entering the data.
¬¬ Information is chnages form of data

Hardware components of a computer

A computer hardware components include input devices,
output devices, a system unit, storage devices, and some other
communication devices. Let’s discuss about the components of a
computer system.

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.
yy What is a computer?
yy What are data?
yy What is a hardware?
yy What is software?
yy Is the computer hardware an input device?
yy Is the storage device a computer hardware?

Introduction to Computer 3

Input device

An input device is any hardware
component that allows a user to enter
data and instructions into a computer.
Some commonly used input devices are
keyboard, mouse, microphone, scanner,
digital camera, and PC camera.

Output device

An output device is any hardware
component that can convey
information to a user. Output
devices gives the result either in
audio or in visual format. Some commonly used output devices
are a printer, a monitor, and speakers.

System Unit

The system unit is a box-like case made of metal
or plastic that protects the internal electronic
components of the computer from damage. The
system unit contains the central processing unit,
memory, motherboard, hard disk, etc.

The central processing unit (CPU)

The Central Processing Unit (CPU) is the
electronic device that interprets and carries
out the basic instructions to operate the
computer. It is a brain of the computer that
helps to process the data. The CPU has three
sections; they are control unit, memory unit and Arithmetic Logic
Unit (ALU).

4 New Gateway to Computer Science Book 4

Storage device

A storage device records and retrieves data to
and from a storage medium. Some commonly
used storage devices are a floppy disk drive, a
Zip drive, a hard disk drive, a CD-ROM drive,
a CD-RW drive, a DVD-ROM drive, and a
DVD+RW drive. Among those devices hard disk is essential to
work with the computer system.

Communication device 

A communication device enables the computer
users to communicate and exchange items such
as data, instructions, and information with
another computer. For example: a modem is a
communication device.

The working principle of the computer

All modern computers function on the same general model
of input, process and output.

Input Processing Output

A computer receives an input, processes the information, then displays

an output. Quick Learn!

Let’s take an example of sending a ¬¬ A communication device
text message from a mobile phone: helps the computer user
input  : type in the message box to communicate with the
computer system.
and press send.

process : the phone's hardware ¬¬ Input – Process - Output
and network process is the basic working
principle of the computer.
the message.
¬¬ Hard disk, pen drive and
output : the message goes to the memory card are the
receiver. popular storage devices.

Introduction to Computer 5

Let’s observe the given diagram. Printer

Scanner Microprocessor

Speaker

Camera

Mouse Keyboard Monitor

Input Processing Output

The given examples make us clear about the input-process-output
sequences.

Printer

Input Process Output

A Printer receives The printer stores A document is

a document from a the document in its printed out in the

computer. memory. paper.

Microwave

Input Process Output

A User presses The microwave switches The microwave

buttons to select to the allocated mode and beeps and the

the power level heats up the contents for the user removes the

and time. duration selected. heated food.

6 New Gateway to Computer Science Book 4

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.
yy Name any two input devices.
yy Name any two output devices.
yy Name any two storage devices.
yy Tell the working principle of the computer.
yy Is MODEM a communication device?

Characteristics of a computer

Speed Quick Learn!

As we know, a computer can work at The basic characteristics
a very high speed. It takes only few of the computer are:
seconds for calculations that we take ¬¬ Speed
hours to complete. The computer ¬¬ Accuracy
can perform millions of instructions ¬¬ Diligence
¬¬ Versatility
within a very few seconds. ¬¬ Storage
¬¬ Automatic
Accuracy

The degree of accuracy of a computer

is very high and every calculation is performed with the same

accuracy. If human enters the wrong data in the computer, the

computer produces wrong output. Otherwise it always displays

accurate output which is also called result.

Diligence

A computer is free from tiredness, lack of concentration,
weakness, etc. It can work for long hours without creating any
error. If millions of calculations are to be performed, a computer
will perform every calculation with the same accuracy.

Introduction to Computer 7

Versatility

Versatility means the capacity to perform completely different
type of work. We can use computer for different purposes and at
various areas like education, business, communication etc. It can
be used at everywhere, so it is called versatile machine.

Storage

The Computer has an in-built memory where we can store a large
amount of data. We can also store data in secondary storage
devices such as hard disk, memory card, CD, DVD, etc. When we
save the data in the secondary storage, then we can get it easily
whenever we need.

Limitations of Computer

Computer is a powerful electronic device. However, it has some
limitations. Some limitations of the computer are as follows.
¬¬ A computer does not have self-thinking power.
¬¬ It cannot be used on the dusty and the rough environment.
¬¬ Computer is expensive device, so it cannot be affort by all.
¬¬ Repairing and maintains is difficult.
¬¬ Skilled manpower is required to work with the computer.

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.
yy Tell any four characteristics of the computer.
yy Tell any four limitations of computer.
yy Why is the computer a versatile machine?
yy What do you mean by diligence?
yy Is the memory card a storage device?

8 New Gateway to Computer Science Book 4

Let's Revise

áá A computer accepts data and instructions as input and
stores them on the memory to process them.

áá The data are collection of raw unprocessed facts, figures,
and symbols. 

áá Information is organized, meaningful, and useful data.
áá Hardware  is the physical equipment that makes up a

computer. 
áá Software is the set of instructions that tells the hardware

how to perform the tasks.
áá A computer is a powerful tool because it is able to perform

input, process, output, and storage with a very high speed
within few seconds.
áá Hardware components include input devices, output
devices, a system unit, storage devices, and some other
communication devices.
áá An input device is any hardware component that allows a
user to enter data and instructions into a computer.
áá An  output device  is any hardware component that can
display information to a user.
áá The system unit is a box-like case made of metal or plastic.
áá A storage device records and retrieves data to and from a
storage medium.
áá A computer can work at a very high speed.
áá A computer takes only few seconds for calculations.
áá The degree of accuracy of computer is very high.
áá A computer is free from tiredness, lack of concentration,
weakness, etc.
áá We can also store data in secondary storage devices.
áá A computer does not have self-thinking power.

Introduction to Computer 9

Evaluation Time

1. Select the best answer from the given options.

a. The collection of raw unprocessed facts, figures, and
symbols.

i. Data ii. Output iii. File

b. It is the physical equipment that makes up a computer
system. 

i. Software ii. Hardware iii. Input

c. The set of instructions that tells the hardware how to
perform the tasks.

i. Hardware ii. Software iii. Processing

d. Which of the following in an input device?

i. Scanner ii. Printer iii. Monitor

e. Which of the following in an output device?

i. Scanner ii. Printer iii. Light Pen

f. Which of the following is the characteristics of a computer?

i. Accuracy ii. Storage iii. Both

2. Fill in the blanks with suitable words.

a. ……………………… is a collection of raw unprocessed facts,
figures, and symbols. 

b. ………………  is organized, meaningful, and useful data.

c. …………………. is the physical equipment that makes up a
computer. 

10 New Gateway to Computer Science Book 4

d. ………………. is the set of instructions that tells the
hardware how to perform the tasks.

e. An ………………..device is any hardware component
that allows a user to enter data and instructions into a
computer.

f. An …………………. device is any hardware component that
can convey information to a user.

g. The ……………………… is a box-like case made of metal or
plastic.

h. The degree of ………………….. of a computer is very high.

i. A computer is free from ………………….., lack of
concentration, weakness, etc.

j. We can also store data in …………………….. devices.

3. Write True for correct and false for the wrong
statements.

a. It is almost impossible to pass a single day without a
computer.

b. After processing, the computer displays the desired input.

c. Computers process data to produce information.

d. The data are collection of raw unprocessed facts, figures,
and symbols.

e.  Input  is organized, meaningful, and useful data.

f. To process data into information, a computer uses
hardware and software

Introduction to Computer 11

g. A computer is a powerful tool because it is able to
perform input, process, output, and storage with a very
high speed in a few seconds.

h. An output device is any software component that allows
a user to enter data and instructions into a computer.

i. An input device is any hardware component that can
convey information to a user.

j. The system unit is a box-like case made of metal or
plastic that protects the internal electronic components
of the computer.

k. The central processing unit (CPU) is the electronic device
that interprets and carries out the basic instructions that
operate the computer. 

l. The computer RAM (Random Access Memory) is a
permanent holding place.

m. The computer has its self-thinking power.

4. Answer these questions:
a. Define the term ‘Computer’.
b. Define data, hardware and software.
c. What do you mean by input and output device?
d. Define system unit.
e. What is a communication device?
f. Write down the working principle of computer.
g. Mention any five characteristics of a computer.
h. Write any four limitations of a computer.

12 New Gateway to Computer Science Book 4

5. Find the given words from the given table.

USER DATA INPUT COMPUTER
RAM MOUSE STORAGE OUTPUT

A B C PULM

C D OWV UN

R AMOU S E

DT PUS TO

E AUT EOP

FGT PRRQ

I HEUXAR

J KRT YG S

I NPUTET

Project Work

## Draw a figure for a working principle of computer in an
A4 paper and show it to the teacher.

## List out the limitation and features of a computer and
paste it in your class notice board.

## Draw a figure of computer system and show it to your
subject teacher.

Introduction to Computer 13

Unit 2 Importance of
computer

Expected Competency
At the end of this unit, students will be able to,
¬¬ explain the importance of computer
¬¬ tell the advantages and disadvantages of computer.
¬¬ list the application areas of computer.

14 New Gateway to Computer Science Book 4

Introduction

The modern life of people is so
interesting because of the use of
technology. We can connect to
the people of the world within
few seconds. There is a great role
of the computer for this great
achievement. To know all about
such things, computer education is essential. When a person
knows the uses and importance of computer; he or she can work
very easily with the computer technology.      

The knowledge and the uses of computer are essential for each
and every person. Computers help the people in different ways.
The use of computer is increasing day by day. Nowadays, people
are massively using computer everywhere such as at hospital,
bank, departmental store, school and colleges, entertainment
and for communication, etc.

In this lesson we are going to discuss some of the advantages,
disadvantages and application areas of the computer.

Advantages and disadvantages of computer

The role of computer is great in this modern age. It has changed
the life of human. People are using computer for various purposes.
If we do not use computer in proper manner, it will create a lot of
disadvantages. Here, we are going to discuss about the advantages
and disadvantages of the computer.

Importance of computer 15

Advantages of Computer

Our work becomes easy and faster with the help of computer.
It is possible to store large volume of data.
The output of the computer is always correct.
A computer can work for a long time without loosing its

speed and accuracy.
When a user gives commands, it starts to work

automatically.
It is used for various purposes.

Disadvantages of Computer

A computer is useless without electricity.
It may create health problems.
A computer cannot work itself.
It does not have self decision capacity.
It has increase the dependency on machine.
A trained person is required to handle it.
Criminal activities are increasing due to the misuse of

computer.

Quick Learn!

¬¬ With the help of computer, we can connect to the people of
the world with in few seconds.

¬¬ The knowledge and the uses of computer are essential for
each and every people.

¬¬ The use of computer is increasing day by day.
¬¬ Computers are popularly used at hospital, bank, department

store, science, entertainment, education etc.

16 New Gateway to Computer Science Book 4

Application areas of computer

Computers have become

an essential and powerful Entertain- Education
device of modern human ment

life. It is one of the fastest

developing technology. Application Bank and
Life in today’s world would area of Financial
be unimaginable without
Computer sector

Business

computers. They have

made human lives better Hospital

and happier. There are

many application areas of computer. We are going to discuss

some application areas of computer below.

Computer in Education

Nowadays, computers are
commonly used in school and
college for teaching and learning
activities. A teacher can make
his teaching techniques easier
and interactive with the help of
computer tools. Students can
also use computer as their learning tools. Students can search
about various topics on the internet and teacher also can take
the help of the internet and do lots of research works, so that he

Importance of computer 17

can collect lots of ideas and information about learning process.
A teacher can prepare a slide and demonstrate it in the class.
Students also can do research work in their various subjects that
they want.
Do you know Cyber schools?

A cyber school is a school that uses the Internet as a delivery
tool to offer courses. The course materials and video lectures
are available on the web site. By using video-conference, the
tutors can talk to students in various locations and answer
their questions in real time. Students can also exchange
ideas through interactive discussion groups. There are some
advantages of cyber schools.
Students can attend classes anytime, anywhere, and at

anyplace.
Students can attend classes without communicating with

each other.
The tuition fee of cyber schools is usually lower than that

of the general schools.

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.
yy Tell any four advantages of the computer.
yy Tell any four disadvantages of the computer.
yy Can student use the computer tools for learning?
yy What is the role of the computer in education?
yy Tell few lines about Cyber School?

18 New Gateway to Computer Science Book 4

Computer in Bank

Banks are using computers massively
these days to handle the banking
transactions. With the help of
computers, we can keep the records of
customers; we can calculate the money,
check the balance, verify the signature,
deposit and withdraw money, etc.
Online banking, mobile banking, ATM
card, Electronic Fund Transfer system etc. are also available
because of the use of computer at bank.

Do you know internet banking?
Internet banking can be used to transfer money from one
account to another. It also helps to:
pay online bills.
check account balances and transaction history.
request cheque books.
change personal identification number.
apply for credit cards and other services

Computer for entertainment

Entertainment is also an important
part of human life. Computers are
used for listening music, watching
videos and films, play games, online
booking of film tickets, download
music and videos, etc. So the
computer plays a major role in the entertainment sector too.

Importance of computer 19

Do you know Edutainment?
Edutainment comes from two words that are education
and entertainment. It means the combination of education
with entertainment. Most of the edutainment software use
multimedia elements to entertain the learners.

Computer at hospital

Hospitals use computers to keep
the records of patients, doctors and
staff. They use computers to keep and
display the duty schedule of doctors
also. Computers are used to check
the various internal organs of human,
so that it is easy to find out the health problems. X-Ray , CT-
Scan, test of heart, test of kidney, endoscopy, ultrasound, etc. are
possible to do within a second with the help of computer. So there
is a great role of the computer in the medical science.

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.
yy Can we check bank balance from the online banking?
yy Tell the use of computer at bank.
yy What are the uses of internet banking?
yy For what purpose are computers used at library?
yy Why are computers used at hospital?
yy Tell about edutainment.

20 New Gateway to Computer Science Book 4

Quick Learn!
Application areas of Computers.
Education

¬¬ It is used as a teaching learning tool.
¬¬ It is used for result processing.
¬¬ It is used to prepare monthly bills.
¬¬ It is used to keep the records of teachers.

Health and Medicine

¬¬ Research in health.
¬¬ CT-Scanning and Ultra sound
¬¬ Record keeping of patients
¬¬ Performing the various clinical tests

Banking

¬¬ To provide online and mobile banking facilities
¬¬ To provide ATM facilities
¬¬ To check the bank balance.
¬¬ For the signature verification purpose

Library

¬¬ To keep the records of books
¬¬ To check the available stocks of books.
¬¬ To enter the issue date and return date of book.

Importance of computer 21

Let's Revise

áá The knowledge and the uses of computer are essential
these days.

áá We can work fast and easier with the help of computer.
áá It is possible to store large volume of data in the computer.
áá The output of the computer is always correct if the input

is correct.
áá A computer is useless without electricity.
áá More uses of computer for a long time without rest may

create various health problems.
áá A computer cannot work itself.
áá Computers are commonly used in school and college for

teaching and learning activities.
áá Computers are used in bank to keep the records of

customers; It can be used to calculate the money, check
the balance and verify the signature.
áá Computers are used for listening music, watching videos
and films.
áá Computers are used at hospital to keep the records of
patients, doctors and staffs.
áá Edutainment comes from two words that are education
and entertainment.
áá Edutainment means education with entertainment.

22 New Gateway to Computer Science Book 4

Evaluation Time

1. Fill in the blanks with suitable words.

a. We can work ………............ and easily with the help of
computer.

b. It is possible to ………............ large volume of data in the
computer.

c. The ………............ of the computer is always correct if the
input is correct.

d. Computers are commonly used in ………............ and
………............ for teaching and learning activities.

e. Computers are used in ………............ to keep the records
of customers of bank.

f. Computers are used at ………............ to keep the records
of patients, doctors and staffs.

g. A cyber school is a school that uses the ………............ as a
delivery tool to offer courses.

h. ………............ comes from two words that are education
and entertainment.

i. ………............ means education with entertainment.

2. Write True for correct and False for the wrong
statements.

a. The modern life of people is so difficult because of the
use of technology.

b. The use of computer is decreasing day by day.
c. We can work fast and easily with the help of the computer.

Importance of computer 23

d. A computer can work even without electronic source.
e. A trained person is required to handle the computer.
f. A teacher can prepare a slide and demonstrate in the

class.
g. Online banking, mobile banking, ATM card, Electronic

Fund Transfer, etc. are the features of using computer at
hospital.
h. The computers are used for listening music, watching
videos and films.
3. Answer the given questions:
a. What are the importance of a computer?
b. Write any four advantages and disadvantages of the
computer.
c. What are the application areas of the computer?
d. What is the role of the computer in education?
e. Write few lines about Cyber School.
f. Why is internet banking used? Write any four points.
g. Explain the role of the computer in hospital.
h. Write few lines about edutainment.

Project Work

With the help of your teacher, make a list of various
application areas of the computer and demonstrate them in
the class.

24 New Gateway to Computer Science Book 4

Unit 3 Input
Hardware

Expected Competency
At the end of this unit, students will be able to:
¬¬ explain most of the input hardware devices such as

keyboard, mouse, light Pen, touch pad, touch screen,
microphone and optical scanner.

Input Hardware 25

Introduction

The way of sending the data and instructions to the computer is
input. Input is possible to send data with the help of input devices
only. The device which is used to send data and instructions
to perform a task is called input device. Without input, the
computer cannot do any task. When you give input, then it starts
to process. The keyboard and mouse are the most commonly used
input devices, but there are other various input devices with the
computer system which we are going to discuss in this chapter.

Keyboard: Quick Learn!

A keyboard is the most common input ¬¬ Keyboards, Mouse,
device by which we can send data
and instructions to the computer for Touchpad, Joystick,
processing. The shape of a keyboard
is like a typewriter. There are several Trackball, Web
keys on the keyboard like alphabet
keys, function keys, number keys, camera, Scanner,
special keys and arrow keys. Normally
there are 104 keys with a keyboard. Touch screen,
Let’s discuss more about the keys of
a keyboard. Microphone, etc.

Keys of keyboard are the popular

Alphabet keys input devices.

Alphabet keys contain the letters from A to Z. These buttons are
arranged in three rows. When we press all the alphabet keys, they
appear in small letter, but when we press the Caps Lock key and
start typing; all the alphabets appear in capital letters.

26 New Gateway to Computer Science Book 4

Numbers Keys

These keys contain the numbers from 0 to 9. We
can see these keys on two places of keyboard.
One is at right side of the keyboard and another
is just below the function and above the alphabet
keys. The set of numbers on the right side of the
keyboard is called Numeric Keypad.

Function Keys

In most of the keyboard, the
function keys are located on
the top of the keyboard. There are 12 function keys which are
notated from F1 to F12. Each of the function keys has the specific
task. There are some multimedia keyboards. In multimedia
keyboard, the function keys are located below the multimedia
keys and above the number keys.

Arrow Keys

Arrow keys are called as the cursor control
keys used for moving the cursor on the screen.
It is used to move the cursor in any direction
like up, down, left and right.

Special Keys

We can see various special keys on a keyboard like Enter,Caps
Lock, Backspace, Home, End, Delete, Shift, Alt, etc. These all are
special keys. Some special keys are described below.

Backspace

We can use backspace key to remove the text,
letter or number. We can see this key just above
the enter key in most of the keyboards.

Input Hardware 27

Delete Key

It is used to erase a letter or number on the right
side of the cursor position. It is notated by Del on
the keyboard.

Enter Key

It is used to move the cursor to the next line. When we
want to start a new line or paragraph, we can use this
key. It is indicated by (Enter) on the keyboard.

Home Key

It moves the cursor to the beginning of a line.

End Key

It is used to move the cursor to the end of the line.
If our cursor is in the beginning of the line, we can
press End key to send it to the last of our line.

Spacebar key

It is used to create a blank space between
the characters or words. It is located at the
end row of the keyboard.

Esc Key

It is called escape key which is located at the top
left side of the keyboard. It is used to cancel the
execution of any command.

Shift key

It is used in combination with other keys.
We can use it to type special character and
capital letter. It is located between Ctrl
and Caps Lock key.

28 New Gateway to Computer Science Book 4

Caps Lock key

It is used to change the mode of text either in small or capital letter.
When Caps Lock key is on, we can start typing in capital letter.

Quick Learn!

¬¬ Alphabet , Number, Function, Arrow, Special, Backspace,
DEL, End, Home, Spacebar, Enter, Esc, Shift , Caps Lock,
etc. are the popular keys found on most of the keyboards.

¬¬ The function keys indicate F1 to F12 keys.
¬¬ The arrow key is used to move the cursor in any direction

like up, down, left and right.

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.

yy What is input?
yy What is an input device?
yy Is a keyboard an input device?
yy Name any six keys of a keyboard.
yy Name the function keys of a keyboard.
yy What is the function of the End key?

Mouse

A mouse is an electro-mechanical, handheld
device. It is used as a pointer. It can perform
functions like selecting menu commands,
moving icons, re-sizing windows, starting
programs, and choosing options. We can

Input Hardware 29

draw pictures, play games and music with the help of a mouse.
Normally, a mouse has three buttons with scroll button. We can
use the mouse pad for the smooth functioning of a mouse.

Some actions of mouse
Click

When we click the mouse button, it selects an item on the screen.
To click, we can press the left mouse button once.

Right click

It displays a list of commands on the screen, you can press the
right mouse button and release it to see the effect.

Double click

It means to press and release the

left mouse button twice at a short Quick Learn!

time. It helps to open a document ¬¬ A mouse is an
or program.
electromechanical,

Drag and drop handheld device.

To move the objects from the ¬¬ Click, Right click,
screen we can perform this action. Double Click, Drag
Drag means clicking and dragging and Drop, etc. are the
popular mouse actions.
the mouse at the same time and

drop means releasing the mouse after moving the objects.

Tips to handle the mouse

Put your palm comfortably on the mouse.

Use the thumb, little and right finger to hold it lightly.

If you are going to use scroll mouse button, use the index
finger to scroll the wheel.

30 New Gateway to Computer Science Book 4

Move the mouse slowly on the mouse pad to move the
position of the pointer or cursor.

Light Pen

It is an input device that utilizes a light-
sensitive sensor to select the objects on a
display screen. It allows the user to point
the displayed objects or draw on the
screen. The first light pen was developed
in 1955 AD. The user can bring the light pen to the desired point
on the screen and presses the pen button to make drawing on the
screen.

Touch Pad

It is a touch sensitive pad which is used as a
pointing device. It is mostly used on laptop,
palm top, note book and in some other
handheld devices. This input device is used
for pointing on the screen. We can directly
touch and move it with the help of finger to
select and work with program icon.

Quick Learn!

¬¬ Light pen allows the user to point on the displayed objects
or draw on the screen.

¬¬ The first light pen was developed in 1955 AD.
¬¬ Microphone is an input device, which takes voice as input.
¬¬ A scanner is also a popular input device.

Input Hardware 31

Touch Screen

‘Touch panel displays’ and ‘pads’ are
now being popular these days. These
devices are used as an alternative of
a keyboard. Here the input can be
given through the computer screen,
that accepts the input through the
monitor; users touch electronic
buttons displayed on the screen or they may use light pen. User
can use their fingers to select the object instead of mouse and
light pen.

Microphone

Microphone is an input device, which takes
voice as input. Using this device, a user can
record speech and sounds in the computer. It
can also be used in the internet while chatting.
There are two types of microphones available;
they are desktop microphone and hand held
microphone.

Optical scanner

A scanner is an electronic device which
can capture images and convert them into
digital formats. Different types of scanners
are available with different resolutions.
Using the scanner,we can directly input
the data into the computer without typing
through the keyboard. We must have the
scanner software to attach a scanner with a computer system.

32 New Gateway to Computer Science Book 4

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.
yy What is a mouse?
yy Name the buttons of a mouse.
yy What do you mean by double click?
yy When was light pen developed?
yy Is microphone an input device?
yy In which devices can we use the touch pad?

Let's Revise

áá A keyboard is the most common input device.
áá There are several keys on the keyboard like alphabet keys,

function keys, number keys, special keys and arrow keys.
áá In most of the keyboard, the function keys are located on

the top of the keyboard.
áá Arrow keys also called as cursor control keys are used

for moving the cursor on the screen.
áá Backspace is used to erase the character or number on

the left of the cursor.
áá A mouse is an electro-mechanical, handheld device.
áá Click, Right click, Double click, Drag and drop are the

some actions of the mouse.
áá Touch Pad is a touch sensitive pad which is used as a

pointing device.
áá Microphone is an input device, which takes voice as input.
áá A scanner is an electronic device which can capture

images and convert them into digital formats.

Input Hardware 33

Evaluation Time

1. Select the best answer from the given options.

a. How many keys are there in normally used keyboard?

i. 104 Keys ii. 110 keys iii. 115 Keys

b. Which of the following belongs to alphabet keys?

i. 0-9 ii. F1-F12 iii. A-Z

c. Which keys are called as the cursor control keys?

i. Arrow Keys ii. Space Key iii. Function keys

d. The key which is used to erase a letter or number on the
right side of the cursor position.

i. Backspace Key ii. Delete key iii. Space key

e. Which of the following is the longest key on the keyboard?

i. Enter key ii. Space Bar Key iii. Control Key

f. Which of the following is an action of mouse?

i. Right Click ii. Double click iii. Both

g. Which of the following is touch sensitive pad which is
used as a pointing device?

i. Mouse ii. Keyboard iii. Light pen

Which of the following is an image input device?

i. Keyboard ii. Scanner iii. Mouse

34 New Gateway to Computer Science Book 4

2. Fill in the blanks with suitable words.

a. We can give data and instructions to the computer for
processing with the help of ……………………..

b. There are several keys on the …………………… like alphabet
keys, function keys, number keys, special keys and arrow
keys.

c. …………………. keys are located on the top of the keyboard in
most of the keyboard.

d. ………………… are called as cursor control keys used for
moving the cursor on the screen.

e. ……………………..is used to erase the character or number on
the left of the cursor.

f. …………………..is a touch sensitive pad which is used as a
pointing device.

g. …………….. is an input device, which takes voice as input.

h. A ………………. is an electronic device which can capture
images and convert them into digital formats.

3. Write True for correct and false for the wrong
statements.
a. The way of sending the data and instructions to the
computer is input.
b. Those devices which are used to send data and instructions
to perform a task is called input device.
c. The keyboard and mouse are the most commonly used
input devices.

Input Hardware 35

d. A keyboard is the most common input device by which
we can give data and instructions to the computer for
processing.

e. Normally there are 110 keys with a keyboard.
f. The special key contains the letters from A to Z.
g. In most of the keyboard, the function keys are located on

the button of the keyboard.
h. There are 10 function keys which are notated from F1 to

F12.
i. In multimedia keyboard, function keys are located below

the multimedia keys and above the number keys.
j. The arrow keys are called as cursor control keys.
k. Home, End, Delete, Shift, Alt, etc. are called alphabet keys.
l. The delete key is used to erase a letter or number on the

right side of the cursor position.
m. A scanner is an electronic device which can capture images.

4. Write down the function of following keys of a
keyboard.
a. Arrow Key b. Backspace Key c. Enter Key
d. Special Keys e. Home Key f. End Key

5. Answer these questions:
a. Define input and input devices.
b. What is a keyboard? Name any five keys of the keyboard.
c. Define mouse. Write down the various actions of a mouse.
d. What is a light pen and touch pad?
e. Write few lines about the touch screen.

36 New Gateway to Computer Science Book 4

f. What is a scanner? What is the use of the scanner?
g. Define Microphone. For what purpose we can use the

microphone?

6. Find the given words from the following puzzle.

SPECIAL FUNCTION ENTER NUMBER
SHIFT
END BACKSPACE DELETE

ALPHABET HOME KEYBOARD

ENTERASDJ K
R U P N A C DNML
TMBDE L E T E Z
F BACKS PACE
UE SMEHT L X Y
NR P P Y I P P TM
C S E T B F I HMT
THCQOT CADF
I O I RAPHB I H
OMA C R VME N R
NE L DDHQ T EG

Project Work

Prepare a chart paper with various input hardware and
paste it in your class.

Input Hardware 37

Unit 4 Output
Hardware

Expected Competency
At the end of this unit, students will be able to:
¬¬ explain about the monitor and printer.
¬¬ explain about the types of monitor and printer.

38 New Gateway to Computer Science Book 4

Introduction

As we know that output is the processed data. The output can
be displayed by the output devices only. It means we must have
an output unit to work with the computer system. The output
devices display the processed data after processing. Output is the
result produced by the central processing unit. The most common
output devices are computer screens and printers. We are going
to discuss in details about the output hardware in this chapter.

Monitor

A monitor looks like a television screen. It is a popular output
device without which output is not possible. Monitor is a softcopy
output device because the output of the monitor can be changed.
It is also called as VDU(Visual Display Unit). There are two types
of monitor; they are CRT (Cathode Ray Tube) and LCD (Liquid
Crystal Display) monitor. Nowadays, almost CRT monitors are
replaced by the LCD monitors.

Quick Learn!

¬¬ VDU stands for Visual Display Unit.
¬¬ CRT stands for Cathode Ray Tube.
¬¬ LCD stands for Liquid Crystal Display.
¬¬ CRT monitors are traditional types of monitors.
¬¬ The laptops computers use LCD screen.
¬¬ CRT monitor use vacuum tube technology.

Output Hardware 39

CRT Monitor

This monitor is the traditional type of
monitor. We can see Cathode Ray Tube
(CRT) Monitor on a desktop computer.
It looks like a television screen and
works in the same way. This type of
monitor uses a large vacuum tube,
called cathode ray tube (CRT).

LCD Monitor

Liquid Crystal Displays (LCD) monitor
is also called flat panel monitor. Most
of these employ liquid crystal displays
(LCDs) to render images. These days,
LCD monitors are very popular. These
monitors use the liquid crystal display
(LCD) technology and connect to a
computer. The laptop computers use LCD screens. LCD monitor is
the standard display screen for desktop computers.

Difference between CRT and LCD monitors

CRT LCD

CRT stands for Cathode Ray LCD stands for Liquid Crystal

Tube. Display.

CRT is heavy and large in size. LCD is light, compact and thin
in size.

It consumes high power. It consumes less power.

40 New Gateway to Computer Science Book 4

More flickering in the image. No any flickering of images.

It shows the actual colour It may not show the actual

resolution colour resolution.

It is less expensive. It is more expensive.

Electron Gun is used to form Liquid crystals are used to form

images. images.

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.

yy What is output?
yy What is an output device?
yy Is the monitor a soft copy output device?
yy Name any two output devices.
yy What is the full form of CRT and LCD?
yy Does CRT monitor produce better quality of output than

LCD monitor?

Printer

A printer is an output device to display the result in the form of
hard copy. Output displayed by the printer is called hard copy
output because the output displayed by it cannot be changed. To
see the printed output, we should have a paper. In order to print a
document, the electronic data must be sent from the computer to
the printer. Some of the most commonly used printers are Laser
Printer, Ink Jet Printer, Dot Matrix Printer, Line Printer, etc. We
are going to discuss about the different types of printers here.

Output Hardware 41

Quick Learn!

¬¬ A printer is a hardcopy output device.
¬¬ Laser printer, ink-jet printer and dot matrix printers are

the some popular types of printers.
¬¬ The speed of Dot Matrix Printer is measured in characters

per second (CPS).

Laser Printer

A laser printer produces high quality
print. It is extremely fast and quiet. The
operation of a laser printer is easy with
automatic paper loading and no smudging
or messing up of ink ribbons. The fastest
laser printer can print up to 200 pages per
minute in monochrome (black and white) and up to 100 pages
per minute in colour.

Ink-Jet Printer

An ink-jet printer creates an image directly
on paper by spraying ink through as many
as 64 tiny nozzles. The image it produces
is not much sharper as of a laser printer.
Like laser printer, an ink-jet printer is
quiet and convenient, but not as fast as
laser printer. Typically, an ink-jet printer is more expensive than
a dot-matrix printer.

42 New Gateway to Computer Science Book 4

Dot Matrix Printer

It is a type of printer that uses tiny
hammers in its print head to strike pins
over an inked ribbon to form characters
or images on paper. Dot matrix printers
are replaced by ink jets and laser printers.
The print head physically "hits" the paper through the ribbon
and produces text (or images) by combinations of dots in dot
matrix printer. The speed of Dot Matrix Printer is measured in
characters per second (CPS).

Speaker

Speaker is an output hardware
device that is connected with a
computer system to produce a sound.
The purpose of speakers is to produce
audio output that can be heard by the
listener. The speakers receive audio
input from a device such as a computer
or form other handheld devices.

Oral Evaluation

Ask the given questions in the class to determine the
understanding level of students.
yy Which device is hard copy output device?
yy Name any three types of printers.
yy Is speaker an input hardware?
yy What is the speed measurement unit of dot matrix printer?
yy What is the full form of CPS?

Output Hardware 43

Let's Revise

áá The output can be displayed by the output devices only.
áá The output devices display the processed data after

processing.
áá A monitor looks like a television screen.
áá A monitor is a popular output device without which

output is not possible.
áá A monitor is a softcopy output device because the output

of monitor can be changed.
áá Monitor is also called as VDU(Visual Display Unit).
áá There are two types of monitors; they are CRT (Cathode

Ray Tube) and LCD (Liquid Crystal Display) monitor.
áá CRT Monitor is the traditional type of monitor.
áá Liquid Crystal Displays (LCD) monitors are also called

flat panel monitors.
áá Printer is an output device to display the result in the

form of hard copy
áá Some of the most commonly used printers are Laser Printer,

Ink-Jet Printer, Dot Matrix Printer, Line Printer etc.
áá A laser printer produces high quality print.
áá The fastest laser printer can print up to 200 pages per

minute in black and white and up to 100 pages per minute
in colour.
áá Dot matrix printers are replaced by ink- jets and laser
printers.
áá Speaker is an output hardware device that is connected
with a computer system to produce a sound.

44 New Gateway to Computer Science Book 4

Evaluation Time

1. Select the best answer from the given options.

a. Which of the following monitor looks like a traditional
television?

i. CRT Monitor ii. LCD Monitor iii. LED Monitor

b. Which of the following monitor is called the flat panel
monitor?

i. CRT Monitor ii. LCD Monitor iii. LED Monitor
c. Which monitor screen is used by laptop?

i. CRT ii. LED iii. LCD

d. Which of the following is a hard copy output?

i. Monitor ii. Printer iii. Speaker

e. Which of the following printer produces high quality
print?

i. Laser ii. Dot matrix iii. Ink-Jet

f. What is the speed measurement unit of Dot Matrix
printer?

i. MBPS ii. CPS iii. MBS

g. Which of the following is a soft copy output device?

i. Printer ii. Speaker iii. Monitor

2. Fill in the blanks with suitable words.

a. The ………………….. display the processed data after
processing.

b. A ………………… looks like a television screen.

Output Hardware 45

c. ………………….. is a popular output device without which
output is not possible.

d. A monitor is a …………… device because the output of
monitor can be changed.

e. A monitor is also called as ………………..

f. A ………………………. monitors are also called flat panel
monitors.

g. …………………. is an output device to display the result in
the form of hard copy

h. A ………………………. produces high quality print.

i. Dot matrix printers are replaced by …………….. and laser
printers.

j. ………………. is an output hardware device that is
connected with a computer system to produce a sound.

3. Write down the full forms of the followings:

VDU , CRT , LCD , LED , CPS

4. Write 'True' for correct and 'False' for the wrong
statement.

a. A monitor looks like a television screen.
b. A monitor is a hardcopy output device.
c. A monitors are also called as Visual Display Units.
d. LCD monitors are replaced by the CRT monitors.
e. LCD monitor uses a large vacuum tube.
f. The laptop computers use LCD screens.
g. A printer is an output device to display the result in the

form of hard copy.
h. A laser printer produces high quality print.

46 New Gateway to Computer Science Book 4

i. The fastest laser printer can print up to 20 pages per
minute.

j. Ink-jet printer is cheaper than a dot-matrix printer.

5. Answer these questions:

a. What is output? Define it.
b. Define a monitor with its types.
c. Why is the monitor called soft copy output?
d. Write a few lines about CRT and LCD monitor?
e. Write any four differences between CRT and LCD monitor.
f. Why is printer called hard copy output?
g. What is laser printer?
h. Define ink-jet and dot-matrix printer.
i. What is the speed measurement unit of dot matrix printer?

6. Find the given words from the given table.

MONITOR PRINTER INKJET
DISPLAY KEYBOARD

K E Y BOARD
P PMA BN J H
D R O TMN Y A
I I NK J ETR
SNI AVYTD
P T T VHHX C
L EOV BQZO
A R RHHB G P
Y L L P A YUY

Output Hardware 47

Unit 5 Secondary
Storage Devices

Expected Competency
At the end of this unit, students will be able to:
¬¬ explain about various storage devices such as Hard

Disk, FLOPPY DISK, CD/ DVD, Pen drive and Memory
Card.

48 New Gateway to Computer Science Book 4