class 4 Flip book for online

Approved by Curriculum Development Centre (CDC) , Sanothimi, Bhaktapur, Nepal Smart Computer Science Book-4 Author Prabhu Ram Khadka M. Sc. IT (SMU), B. Ed. (TU) Memorica Pvt. Ltd. Publishers & Distributors Maitidevi, Katmandu

Book : Smart Computer Science Book-4 Author : Prabhu Ram Khadka Language Editors : Sharan Ratna Sthapit Shivahari Sapkota Publisher : Memorica Pvt. Ltd. Maitidevi, Kathmandu Ph: 01-4438703 Edition : 1st 2076 B.S. (2020 AD) Copyright : All rights reserved with the author ISBN : 978-9937-9382-5-9 Price : NRs. 221.00/- For suggestion and advice please contact at [email protected] Cell : 9841816625, 9813303490 (Viber/Messenger) https://www.facebook.com/prabhuram.khadka.9 URL: www.memoricapublication.com

About this Book Creative Computer Science is a graded series of Eight textbooks prepared for class 1 to 8. This series of book is comprehensively designed on the basis of guide lines and syllabi designed by Government of Nepal, Ministry of education, Curriculum development centre. Beginning with the very basic concept of computer, the series gradually introduces more advanced aspects of computing concept, skill and software to students as they go to higher classes. It attempts to include latest software required for the daily work- ing. I hope, this series shall be helpful in the overall development of the learners. Salient features • Step by step simple technique and tools. • Simple vocabulary and language. • Practical approach based • Worksheet based. • Logical analysis and case study base for enhancing creative- ness. • Activity based. • Project work based. Although I’ve tried my best no to do any mistake as far as possible, some errors may have crept in without noticing. If so that I’d like to request the respected teachers to correct the mistakes for the students. Comments and constructive suggestions from students, teachers and well wishers are always welcome. Constructive advice will be incorporated in the next edition. I duly thank duo of Mr. Sharan Ratna Sthapit and Mr. Shivahari Sapkota for their contribu- tion on editing of language through out the series of books. My hearty thanks go to Mr. Bidhan Khadka for his effort of bringing my work accom- plished. Prabhu Ram Khadka The Author

TABLE OF CONTENTS Pg. no. 1-11 Ch. Title 12-23 24-44 1. Knowing Computer 45-60 2. Evolution of Computer 3. Computer Devices 61-101 4. Microsoft Windows 102-124 5. Painting & Drawing 125-152 6. MS-Word 7. More on LOGO

CHAPTER Knowing Computer 1 Jigme : Hey Mingma! Can you tell me about the computer that you know? Mingma : Computer is an electronic device which accepts data; processes them and gives output result. Jigme : Can you say some reasons due to computers are being special machine? Mingma : Computer works very fast, gives accurate result, never gets tired, it has high storage capacity, etc. So computer is a special machine. Jigme : Have computers any weakness? Mingma : Computers have not their own intelligence and common sense and they can’t work themselves. INTRODUCTION This is the age of computers. Now-a days computers are used almost everywhere. There are big computers as well as handheld small com- puters. Big computer are used in offices, transportation, educational intuition, hospital, communication etc. Where as, small computers are used in watches, cars, toys etc. Computer word is derived from a Latin word ‘Computare’ which means to calculate. It woks on the basis of electric pulses ‘on’ and ‘off’. So, Smart Page Computer Science Book-4 1

computer is defined as “Computer is an electronic data processing device which accepts data and instructions from the input devices, processing them into processing device, gives output information thought the output devices and store them in storage device.” BASIC PRINCIPLE OF COMPUTER Lakpa : I do every work in the system. Sense organs receive from out- side, brain calcu- lates and takes decision and mouth produces speech outside. Computer : I have also same principle that is input-Process- Output. Input devices receive, processing device calculates and output de- vice give information outside. The computer is a man-made machine. It is designed to work on the basis of certain principles, which are presented in the figure: COMPUTER IS IMPORTANT MACHINE Computer provides many benefits to us. The following characteristics Page Knowing Computer 2

of a computer make a computer is so much important for us. High speed Jigme : Hey Mingma, I know that computer can do sums. I also can do such sums. Why is it need- ed? Mingma : Oh! It’s all right. But tell me. how much time you need to solve a simple sum? Jigme : I need almost 1 to 2 minutes. Mingma : That’s why you need computer. It can solve a sum in a fraction of a second. It is very fast. Computer works at high speed. It can solve a sum in the fraction of a second. It can process millions of instructions per second. Accuracy Jigme : Look here Mingma. My answer is not match- ing of this sum. Mingma : Oh! Jigme, you have done mistake. Please do Smart Page Computer Science Book-4 3

on the computer. Jigme : (Start to check in the computer). Yes, now it’s matching. Mingma : Lets look, computer never make mistake. You can make mistake in the calculation but computer is hundred percent accu- rate. Computer never make mistake. Large Storage Capacity Mingma : Once you read a book, can you store it in the brain? Jigme! Jigme : No, I can’t. Mingma : But computer can store it. Jigme : Wow, It’s wonderful! A computer has high storage capacity. It can store whole Ramayana and Mahabharata volumes in a small disk. Page Knowing Computer 4

Computer Never Forgets Jigme : You taught me many things about the com- puter. But I have for- gotten many things. Mingma : No matter, we may forget slowly one by one. There is only the computer that never forgets things once stored even after many years. The data you store in computer’s storage device, it is not erased un- til you delete. So, a computer never forgets things. You retrieve any data or information from computer even after so many years. Diligent Jigme : He Mingma! I have done some sums. Now I am getting tired and felling bored. I have to do many more sums. Can you help me? Mingma : When you can in- Smart Page Computer Science Book-4 5

struct, computer never fells tired and bored. He can do millions of sums continuously. Human being feels tired and bored after doing certain work. But com- puter is a machine, due to this, it never gets tired and bored even after doing millions of calculation. Computer constantly gives effort to complete a task. Versatile Mingma : How many unique woks can you do effi- ciently? Like dancing, swimming, singing, joking, performing magic etc. Jigme : I can’t do such type of unique work. I am a painter. I can do only painting. Mingma : So, Computer is a special machine. It can do many different unique works. Computer can be used almost everywhere. It can perform different types of work. It can be used from typing text to complete complex mathematical calculations. However, human beings can not do many types of work efficiently. So, unlike a man, a computer is versatile. Page Knowing Computer 6

Points to Know • Computer word is derived from a Latin word ‘Computare’ which means to calculate. • Computer is defined as “Computer is an electronic data pro- cessing device. • Input devices receive, processing device calculates and output device produces information outside. • Computer is more reliable machine due to the following char- acteristics: • High speed • Accurate • Large storage capacity • Never forgets • Diligent • Versatile Terms to Know Electronic : Components such as microchips and transistors that control and direct electric currents. Process : Series of actions or steps taken in order to get a particu- lar result. Input : Something as supply data putting into the computer. Output : Something produced by computer. Instruction : Direction or order to do something. Diligent : constant in effort to complete a task. Versatile : Able to do many different functions. Storage : Storing something for future use. Smart Page Computer Science Book-4 7

Worksheet Objective Questions computare output fraction high storage input on and Off electronic 1. Fill in the blanks with the suitable words: a. Computer word is derived from the Latin word ................................ b. Computer is an .................................... data processing device. c. A computer has .................... storage capacity. d. Computer can solve a sum in the ............................. of a second. e. Computer works in the basis of electric pulses .................................... f. Computer stores data in the .............................. device. g. Computer accepts data and instructions from the ................................ device. h. Computer produces the output result through ............................ de- vice. 2. State whether the following statements are true(T) or false (F) a. Computer is a magical device. b. Computer can not forget. c. Computer can perform different types of task. d. Computer feels tired and bored after doing certain work. Page Knowing Computer 8

e. Data can be erased itself from storage device, f. Computer is an accurate machine. g. Computer can process millions of instructions persecond. h. Computer gives the effort constantly to complete a task. Descriptive Questions 1. Answer the following questions: a. What is computer ? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... b. Why do you use computer ? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... c. What is the basic working principle of computer ? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... Smart Page Computer Science Book-4 9

..................................................................................................................................... ..................................................................................................................................... d. Why is computer called versatile machine ? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... e. Where are computers used ? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... Analytical case study Questions 1. Sanduk Lama said \"Computer performs the task repeatedly without losing its speed and accuracy for a long time.\" Which characteristic is being fo- cused by Sanduk? Ans: ............................................................................................................................ ..................................................................................................................................... 2. Bhurka Gauro said \"Computer can be used for all sorts of tasks. It can also do many of the same tasks in different ways.\" Which feature is being fo- cused by Bhurka? Ans: ............................................................................................................................ Page Knowing Computer 10

..................................................................................................................................... 3. Sadhu Ram Chaudhary is working in the School. He has to advise to intro- duce the computers in the School. But School's principal is not interested to introduce computer. How would he convince the principal in this case? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... Activities 1. Manage your class in three groups and organize a chart paper presentation on the following topics: a. Application fields of Computer b. Characteristics of computer 2. Organise a speech competition in the class on the topic \"Computer is diligent and versatile machine.\" Project Work 1. Computer is being used almost in every fields, Where is computer used in your so- ciety and for what purpose ? Prepare and submit a report. The report must include: a. Text b. Picture c. Interview Smart Page Computer Science Book-4 11

CHAPTER 2 Evolution of Computer Zigme : Mingma, how is the today’s computer? Was today’s computer same in earlier days. Mingma : No, it is not the same; it was totally differ- ent in the earlier days. Jigme : Please Merry, can you tell me about the evo- lution of computer? Mingma : I must tell you. Let's learn about some early computing machines. ABACUS Abacus was the first calculating device. It was invented in the sixteenth century (in 3000 BC.) in china. Simple calculations, like addition or subtraction, could be performed using the Aba- cus. The three most popular abacuses were Chinese, Japanese, and Russian. Page Evolution of Computer 12

NAPIER’S BONES Napier’s Bones were invented by John Napier in 1617. It could perform addi- tion, subtraction, multiplication and di- vision. This device was made up of a set of rectangular rods. The improved form of Napier’s Bones were used for performing division and square roots. The rods were made up of craved bones and that is why the device was known as Napier’s Bones. PASCALINE Page Blaise Pascal was a ‘French math- 13 ematician’. He invented the first calculator in 1642 called ‘Pas- caline’. It consisted of a rectangu- lar box with eight movable wheels. The Pascalline could only add and subtract. DIFFERENCE ENGINE Charles Babbage was a math- ematician at Cambridge Uni- versity. In the 19th century, he invented the first mechanical computer called the ‘Difference Engine’. This machine could calculate mathematical table mechanically. Smart Computer Science Book-4

ANALYTICAL ENGINE Charlse Babage also invented the first general purpose computer called ‘Analytical Engine’. The Analytical Engine had the same basic principles as the modern computer as INPUT- OUTPUT – MEMORY. So, Charles Babbage is known as ‘Father of com- puter’. CLASSIFICATION OF COMPUTER TECHNOLOGY Computer technology is classified into following six types, based on their historical advancement of technology and electronic compo- nents used. Zeroth Generation Computers (1642-1946) The zeroth generation of computers was marked by the invention of mainly mechanical computer. Example of zeroth generation comput- ers are ‘Pascline’, ‘Analytical Engine’, etc. First Generation Computer (1946-1959) The first generation of computers were marked by the use of vacuum tubes or valves as basic electronic component. • Size was very big • Long electric wires were used. • A lot of vacuum tubes were used • These computers generated too much heat. • Machine level programming language was used Mark I & ENIAC (Electronic Numerical Integrator Page Evolution of Computer 14

And Computer) were the example of first generation computers. Second Generation Computers(1959-1965) The second generation of computers was marked by the use of transistors in place of vac- uum tubes. • These computers were smaller in size • Produced less heat • Computing speed had increased • Assembly language was used for programming. MARK-III, PDP (Programmed Data Processor) -1, IBM(International Business Machine) 1401, IBM 650 were example of second genera- tion computer. Third Generation Computer(1965-1971) The third generation of computers was marked by the use of integrated Circuit (IC) in place of transistors. • They were smaller in size and cheaper than second generation computer. • They were able to reduce computational time and low maintenance cost. • New input and output devices like scanner, magnetic ink character reader etc. came into the market during this time. • High level languages were developed. • They used as operating system • Capacity of main memories were greatly enlarged PDP-8, IBM 360 and IBM 370 were example of third generation of computers. Smart Page Computer Science Book-4 15

Fourth Generation Computers (1971-1980) The fourth generation of computers was marked by the use of Very Large Scale Integrated (VLSI) circuits in place of ICs. • These computers have microprocessor-based system. • They are the cheapest among all the computer generation. • They have large memory and high functional speed. • Many more high level languages were used such as PASCAL and C language. • Some of the fourth generation computers are IBM 4341, DEC 10, IBM PC, and APPLE- III. Fifth Generation Computer (1980 - onwards) The fifth generation of computers are still under research. These computers will use Ultra Large Scale Integrated (ULSI) circuits in the place of VLSI circuit. They will have artificial intelligence. The main purpose of fifth generation of computer is to create computers that can think, behave and react in the same way as we humans do. For exam ple, Robots have few features of fifth generation computing. Artificial Intelligence Page Evolution of Computer 16

Points to Know • Abacus was the first calculating device. It was invented in the sixteenth century (in 3000 BC.) • Napier’s bones could perform addition, subtraction, multiplication and division. • Blaise Pascal invented a first calculator in 1642 called ‘Pascaline’. • Charles Babbage invented the first mechanical computer called the ‘Difference Engine’. • The Analytical Engine had the same basic principles as the modern computer as INPUT- OUTPUT – MEMORY. • Computer technology is classified into six types, based on their historical advance- ment of technology. • The six phase of computing technology based on : • 0th generation - mechanical technology. • First generation - Vacuum tubes • Second generation - Transistors • Third generation - IC • Fourth generation - VLSI • Fifth generation - ULS Terms to Know Vacuum Tubes : A glass tube that has its gas removed, creating a vacuum. Transistor : A semiconductor device used to amplify or switch electron- ic signals and electrical power.. AI : the simulation of human intelligence processes by ma- chines IC : A semiconductor chip on which thousands or millions of tiny resistors, capacitors, and transistors are fabricated. Mechanical : Operated by use of machinery or tools. Smart Page Computer Science Book-4 17

Worksheet Objective Questions vacuum tubes rods fifth mathematician mechanical eight calculator Analytical Engine 1. Fill in the blanks: a. Napier's Bones were made up of a set of rectangular .............................. b. Pascaline consisted of a rectangular box with ..................................... movable wheels. c. Charles Babbage invented the first ................................... computer called Difference Engine. d. First general purpose computer was called .......................................... e. The first generation of computer was marked the use of .......................... f. The ................................. generation of computers are still under re- search. g. Blaise Pascal invented a first .................................. called Pascaline. h. Charles Babbage was ................................. at Cambridge University. 2. State whether the following statements are true(T) or false (F) a. Robots have few features of fifth generation of computing. b. Pascal and C language were used in fourth generation. c. Fourth generation is based on IC . Page Evolution of Computer 18

d. High level programming language was used in the second gen- eration computer. e. Machine level programming language was used in first genera- tion computer. f. Analytical Engine is an example of zeroth generation of com- puter g. Charles Babbage is called the father of computer. h. Blaise Pascal was a French Mathematician. i. Abacus was the first calculating device. j. The Second generation computing was based on transistors. 3. Write the full forms of following : a. ULSI ...................................................................................................... b. VLSI ...................................................................................................... c. IC .......................................................................................................... d. PDP ....................................................................................................... e. IBM ........................................................................................................ f. ENIAC ................................................................................................... Smart Page Computer Science Book-4 19

4. Write the full forms of following : Device Inventor Invention Date Abacus Napier's Bone Pascaline Difference Engine Analytical Engine 5. Match the following : a. First general purpose computer Abacus b. First mechanical computer Difference Engine c. First calculator Napier's Bone d. First calculator Analytical Engine Pascaline Descriptive Questions 1. Answer the following questions: a. What is the contribution of John Napier ? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... Page Evolution of Computer 20

b. Why is Charles Babbage called father of computer ? Ans: ............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... c. How is the second generation computer more efficient than the first genera- tion computer? Ans: ............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... d. Write three features of the third generation computer ? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... e. What is Abacus ? Ans: ............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... Smart Page Computer Science Book-4 21

..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... f. How is the fourth generation computer is more efficient than the third gen- eration computer ? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... Analytical case study Questions 1. Sukadev Thakur told about the computers which behave as we human be- ing. a. Which generation of computer is he talking about? Ans: ............................................................................................................................ b. Which device is used for this activity? Ans: ............................................................................................................................ 2. Shankar Dev presented his presentation on the topic 'Programming lan- guage' used in different time period of computing technology development. a. Name the different types of programming language that he discussed . Ans: ............................................................................................................................ b. Write the name of time period when those languages were used ? Ans: ............................................................................................................................ Page Evolution of Computer 22

3. Shikha Mandal is assigned a task to make a presentation on the chart pa- per, about the 'Generation of the computer.' a. What would Shikha prepare on the chart paper? Prepare as Shikha Mandal did and paste a photograph. Activities Page 1. Manage your class in three 23 groups and organize a group discussion in the following top- ics: a. Evolution of computer b. Generation of computer 2. Present the chart paper in the class that you had pre- pared as Shikha Mandal on the basis of question no. 3 of analytical case study. Smart Computer Science Book-4

CHAPTER 3 Computer Devices Jigme : Hello Mingma! I have many body organs and each organ has spe- cial function. I re- ceive input from sen- sors organs like eyes, ear, tongue, skin and nose. But it is confus- ing, what about computer? Mingma : Computer has also different parts and each part has special function like your's. Like your sense organs, computer has also input devices like Keyboard, Mouse etc. Jigme : I have got brain to receive instructions from sense organs to do work. It thinks, store and remembers to do any type of task, but what about the computer, Mingma? Mingma : Computer has also like your brain called CPU. It receives the instructions from input and thinks and remembers to perform the task. And it has memory to store information. Page Computer Devices 24

Jigme : I have got mouth, hands, and legs to give the information out by speaking, writing and run- ning, what about the computer? Mingma : Computer grieves the information out with the help of output devices like monitor, printer etc. INTRODUCTION Computer is an electronic data processing machine which accepts data and instructions as input, processes them and give the results as output. The operations that performed by a computer are: INPUT- PROCESS-OUTPUT. INPUT DEVICES Mingma : When you want to talk to a fellow human being, you can eas- ily talk to him or her through your mouth in your language. Your friend too will hear you talking. But what to do, if you want to talk to a computer? Jigme : The only way to talk to a computer is through an input device. Smart Page Computer Science Book-4 25

The input device which are most important part to operate the com- puter. A large verity of input devices are available for entering data and instructions into a computer. The most commonly used input de- vices are called mouse and keyboard. Basically there are two types of input devices: 1. Basic Input Devices 2. Special Input Devices BASIC INPUT DEVICES The input devices which are essential to operate today’s computer are called ‘Basic Input Devices’. These devices are always required for basic input operations. Basically keyboard and mouse are basic input devices which are most essential for today’s every computer. Let 's discus them. Keyboard Keyboard is a basic input de- vice of the computer that is used to enter data and instruc- tions directly into the computer. It has keys similar to the type writer. The keys have letters, numbers and symbols are writ- ten on them. On pressing a key, the characters printed on it get typed. Mouse A mouse is another basic input device. It is used to run a program, pull down menu and select the items on screen. So, it is also called pointing device. It is moved by hand around a flat surface. A small ball underneath rolls as the mouse moves across the mouse pad and Page Computer Devices 26

the cursor on the screen follows the motion of the mouse. A mouse has two or three buttons on the top. Buttons on the mouse can be clicked or double clicked to perform the tasks. Mouse are three types : Mechanical, Optical and Laser. Optical Mechanical Laser Special Input Devices Jigme : Hey Mingma ! When I play games on the computer, I find dif- ficulty in using ‘Basic Input Device’. Mingma : Don’t worry! For games and other spe- cial input task, com- puter has ‘Special Input Devices’ Sometimes basic input devices are difficult to use for special purpose such as drawing, playing games, entering printed text and images, recording voice etc. The input devices which are used for special purposes are called ‘Special Input Devices’. These devices include Trackball, Light Pen, Joystick, Scanner etc. Let us discuss them. Smart Page Computer Science Book-4 27

Joystick Joystick is a special input device called also pointing device. It works like a mouse used to move cursor position on the screen of monitor. It consists of a stick having a spherical ball at both its lower and upper ends. Joystick mainly used to play computer games. Light Pen Light pen is similar to a pen. It is also a point- ing device. It is used to select a displayed menu item or to draw pictures directly on the screen of monitor. Track Ball Track ball looks like a mouse. But its roller is on the top with selection buttons on the side. Track ball is also a pointing device. It works like a mouse. Specially, it is used in ‘Laptop com- puter’. PROCESSING DEVICE Jigme : I am controlled by my brain. All my body’s organs activities are directed by my brain. Mingma : computer has a part that is called CPU. All Page Computer Devices 28

the calculation, decisions are taken in these sections. And other parts of computer do what CPU tells? Jigme : But also it isn’t like human being, it can’t work itself. Am I right? Mingma: Yes, It needs set of instructions to work. CPU (Central Processing Unit) is a brain of the computer where all the calculation and decisions are taken. It also controls other parts of computer to do work. It works as our brain work but it is not real brain, it needs the set of instruction to work called ‘program’. Parts of CPU The CPU (Central Processing Unit) has two parts: • Arithmetic Logical Unit (ALU) • Control Unit(CU) Smart Page Computer Science Book-4 29

Arithmetic Logical Unit Is X>Y ? The ALU (Arithmetic Logical Unit) of the CPU (Central Processing Unit) performs all the arithmetic opera- tions, such as addition, subtraction, multiplication and division. ALU also perform the comparisons called log- ical operations, such as less than, greater than and equal to. Control Unit CU (Control Unit) is a central nerves system of the computer. All the oth- er parts of commuter’s works are controlled by Control Unit. Such as input data through input devices, store data in memory, sending data for operation to ALU, sending re- sult in output device and memory etc. So we can say “CU is a traffic police of the computer that controls all the movement of information among the other parts of computer.” COMPUTER MEMORY Jigme : Hey Mingma ! We can remember any activi- ties for long time, but can computer also re- member? Mingma : Why not! Computer also can remember. It has strong memory power. Page Computer Devices 30

Jigme : We can remember through the brain, how does computer remember? Mingma : Computer has mem- ory device. It stores all the activities in this device, then it can remember. Let's learn about the Compute memory, Jigme. A computer has a large internal memory. It can store a large amount of information and recall it instantly and correctly whenever desired. It holds the data and instructions that the Central Processing Unit (CPU) needs. The basic working unit of the computer's memory is a group of eight bits, which is called a byte. There are two types of memory. • Primary memory • Secondary memory Primary memory It is the main memory of a computer. It is also present inside the CPU. When you input data from the input device, is stored in the pri- mary memory. It also stores immediate processing result and holds the program and data currently being used by computer. There are two types of primary memory. • RAM (Random Access Memory) RAM ROM • ROM (Read Only Memory) Smart Page Computer Science Book-4 31

Secondary Memory The secondary memory is a permanent memory of the computer. It is not erased even when you switch off. So, you can store data and information permanently in this memory for future use. This kind of memory is also called auxiliary memory. Commonly used storage devices are: • Hard Disk • Floppy Disk • Compact Disk • Pen Drive OUTPUT DEVICE Jigme : We produce voice and speak as we like. How does computer per- form this task? Mingma : Computer also pro- duces the output re- sult through the out- put device. Jigme : Wow ! What's of output device, Mingma ? Mingma : Computer has common by three types of out- put devices: Monitor, Printer and Speaker. Page Computer Devices 32

The device which is used to produce the output result to the user is called output device. Monitor, printer, speaker are example of output devices. Monitor Monitor is the screen where whatever you typed can be seen as a output on it. The output display on monitor is known as ‘Soft copy’ output. It forms images from tiny dots, called pixels. The sharp- ness of the image depends upon the number of pixels. Monitors are avail- able in different size, common size of monitors are 17”, 19”, 21” etc. Types of monitor Monitors are classified into following two types in the basis of color of display. • Monochrome Monitor (Display output in color black and white) • Color Monitor (Display output in multi colors) Printer Printer is anther popular out- put device of the computer. it is used to print the information on the paper. There are different types of printers are available: • Characters printer • Line printer • Page Printer Smart Page Computer Science Book-4 33

Character printer Dot matrix Printer Character printers are the oldest printing devices and are still use. These printers print one character at a time. ‘Daisy Wheel Printer’ and ‘Dot Matrix Printer’ are example of character printer. Dot matrix printer is noisy. Line Printer The printer which prints one line at a time is called line printer. It is faster than character printer. Especially it is used to print the light printing appli- cation such as banking token, tele- phone and electricity bill etc. Ther- mal Dot Line printer is an example of Thermal Dot Line Printer ‘Line Printer’. Now a days it is very much popular. Page printer Page printer prints one page at a time. It gives high quality of printing. It is very fast printer. Laser and Ink jet are examples of page printer. Ink Jet Printer Laser Printer Page Computer Devices 34

Speaker A computer speaker is an output hardware device that connects to a computer to generate sound. The signal used to produce the sound that comes from a computer speaker is created by the computer's sound card. Smart Page Computer Science Book-4 35

Points to Know • Computer is an electronic data processing machine which accepts data and instructions as input, processes them and give the results as output. • The most commonly used input devices are called mouse and keyboard. • Keyboard is a basic input device of the computer used to enter data and instructions directly into the computer. • Mouse is used to run a program, pull down menu and select the items on screen. • The input devices which are used for special purposes are called ‘Special Input Devices’. Such as Trackball, Light Pen, Joystick, Scanner etc. • Joystick mainly used to play computer games. • Light pen is used to select a displayed menu item or to draw pictures directly on the screen of monitor. • Track ball works like a mouse. But its roller is on the top with selection but- tons. • CPU (Central Processing Unit) is a brain of the computer where all the cal- culation and decisions are taken. • All the calculation and comparison are done in ALU of CPU. • All the other parts of commuter’s works are controlled by Control Unit. So, it is called central nerves system • Computer memory can store a large amount of information and recall it in- stantly and correctly whenever desired. • Input data, immediate processing result and data currently being used by computer are stored in the primary memory. • You can store data and information permanently in secondary memory for future use. • The device which is used to produce the output result to the user is called output device. Monitor, printer, speaker are example of output devices. Page Computer Devices 36

Terms to Know Electronic : Operating with components such as microchips and tran- sistors that control and direct electric currents. Instruction : Order to do something. Input : Supply something into the computer. Process : Actions or steps taken in order to achieve a particular re- sult. Output : Something displayed or produced by computer Pixels : The smallest unit of a digital image or graphic Device : An object that has been invented for a particular purpose Program : A set of instructions that a computer follows in order to per- form a particular task. Worksheet Objective Questions soft-copy joystick secondary mouse brain light pen processing keyboard 1. Fill in the blanks: a. Computer is an electronic data ............................. machine. b. ............................ is an input device, used to type and enter data and instruction. c. ............................... is used to run a program, pull down menu and select items on screen. Smart Page Computer Science Book-4 37

d. ................................. is mainly used to play video games. e. .............................. is used to draw pictures directly on the screen. f. CPU is a ........................... of the computer. g. The output display on monitor is known as ................................. out- put. h. The ................................ memory is a permanent memory of comput- er. 2. State whether the following statements are true(T) or false (F) a. Joystick is an output device. b. Keyboard a typing input device. c. Light pen is a pointing device . d. Track ball is an output device. e. CPU controls to other parts of computer. f. Primary memory is the main memory. g. Secondary memory is an auxiliary memory. h. Monitor forms image from tiny dots, called pixels. i. The quality of the image depends upon the number of pixels. j. Mechanical mouse is a new technology. k. Speaker is an output hardware device. l. Laser and Ink jet are examples of line printer Page Computer Devices 38

3. Write the full forms of following : a. CPU ...................................................................................................... b. ALU ...................................................................................................... c. CU ......................................................................................................... Descriptive Questions 1. Answer the following questions: a. What do you mean by input device ? Ans: ............................................................................................................................. ...................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... b. Why is CPU called brain of the computer ? Ans: ............................................................................................................................. ...................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... Smart Page Computer Science Book-4 39

c. What is the function of ALU? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... d. What is the function of CU? Why is it called central nerves system? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... e. What is computer memory? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... Page Computer Devices 40

f. What do you mean by byte? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... g. What is the function of primary memory? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... h. Why do you use secondary memory? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... Smart Page Computer Science Book-4 41

i. What do you mean by output device? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... j. What is printer? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... k. Why do you connect speaker with computer? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... Page Computer Devices 42

Analytical case study Questions : 1. Madhukar Rai saw a printing process at the electricity bill office to produce the bill . The printer is very slow printing and producing the noise. a. Which printer Madhukar saw? Ans: ............................................................................................................................. ..................................................................................................................................... 2. Look the following two devices. I) II) a. Write the name of these two devices Ans: ............................................................................................................................. ..................................................................................................................................... b. Where are these device used ? Ans: ............................................................................................................................. ..................................................................................................................................... 3. Ramananda Yadav plays games on the computer. He is getting uneasy to play games with common input device. Which device would you suggest Ramanada for playing game easily? Ans: ............................................................................................................................. ..................................................................................................................................... 4. Ram Prit Paswan is an engineer. He has to make drawing on the computer. Which device is suitable for him ? Ans: ............................................................................................................................. ..................................................................................................................................... Smart Page Computer Science Book-4 43

Activities 1. Manage your class in three groups and organize a group discussion in following topics: a. Input devices b. Processing device c. Ouput devices d. Memory device 2. Prepare and present a chart paper in the class which you have done in the group discussion. Page Computer Devices 44

CHAPTER Microsoft Windows 4 Introduction Microsoft Windows is one of the most popular operating systems, devel- oped by ‘Microsoft Company’ in USA. When you switch on the computer, the windows operating system gets loaded into the computer memory au- tomatically. When loading, the picture of Windows flag will appear on the screen. Windows operating system software are available in different ver- sions such as Windows 95, Windows 98, Windows 2000, and Windows XP. First version Windows was Windows 3.1 Desktop When you switch on your computer, a few seconds after the windows flag appears, you will see the following screen on the monitor with the many small pictures on it. The displayed screen is called desktop and small pic- tures are called icons. Smart Page Computer Science Book-4 45