Digital Book class-6 2nd edition With Coding

Smart Computer Science Book-6 1

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Smart Computer Science Book-6 Author Prabhu Ram Khadka M. Sc. IT (SMU), B. Ed. (TU) Memorica Pvt. Ltd. Publishers & Distributors Maitidevi, Kathmandu Smart Computer Science Book-6 3

Book : Smart Computer Science Book-6 Author : Prabhu Ram Khadka Language Editors : Sharan Ratna Sthapit Shivahari Sapkota Publisher : Memorica Pvt. Ltd. Maitidevi, Kathmandu Ph: 01-4438703/ 9841816625/ 9813303490 Edition : 1st edition 2077 B.S. (2020 AD) 2nd reprint 2079 B.S. (2022 AD) 2nd edition 2080 B.S. (2023 AD) Copyright : All rights reserved with the author ISBN : 978-9937-9382-4-2 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 Teaching Material Video Link  4

About this Book Smart Computer Science is a graded series of ten textbooks prepared for the classes 1 to 10. This series of books is comprehensively designed on the basis of the guidelines 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 working. I hope, this series shall be helpful in the overall development of the computer literacy in the related 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 creativeness • Activity based • Project work based Although I’ve tried my best not to leave print slips as far as possible, some errors may have crept in without noticing. If so that I’d like to request the respected teachers to reach the students correctively. 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 Sharan Ratna Sthapit and Shivahari Sapkota for their contribution on editing of language through out this book. My hearty thanks also go to Mr. Bidhan Khadka for his effort of bringing my work ac- complished. Smart Computer Science Book-6 Prabhu Ram Khadka The Author 5

TABLE OF CONTENTS Chapter Title Page no. Periods 1. Introduction to Computer 1-9 3 2. Introduction to Computer Hardware 10-30 3 3. Memory Device 31-44 3 4. Computer Software 45-53 3 5. ICT & Cyber law 54-68 3 6. Internet and Browsing 69-86 3 7. Multimedia Technology 87-98 3 8. Operating System 99-135 6 9. Typing Skill 136-143 2 10. Word Processing 144-177 10 11. Electronic Spreadsheet 178-213 8 12. Presentation with PowerPoint 214-240 5 13. More on Scratch Coding 241-282 14 Model Question 283-288 Total Periods 66 6

Introduction to Computer CHAPTER LEARN and ACT... 1 Niru : I have heard that computer is smart machine. How is it Ma'am? Teacher : Surely, because computer can perform different tasks in high speed. It doesn't feel tired. It doesn't make mistakes. Niru : Wow, interesting! Can a computer feel and remember, Ma'am? Teacher : No, no ! Computer is a machine, it has some limitations. It has no feelings or emotions. Niru : But, how does it work in a smart way? Teacher : It works on the basis of our instructions. INTRODUCTION The word 'Computer' is an English word which is derived from the Latin word \"COMPUTARE\" which means machine that can compute. The modern computer is developed from the ancient calculating device Abacus. Computer needs electricity power supply and our instruction to do the task. So, simply we can define \"The computer is a smart electronic device which processes raw data and produces the meaningful information.\" Smart Computer Science Book-6 1

APPLICATIONS OF COMPUTER Computer has made it very easy to complete the complicated task. Today, a computer is not just used for calculation but also used in science, engineering, medicine, publishing, forecasting, entertainment, designing, education, research, etc. In this age, the presence of computer is felt in every step of life. TYPES OF COMPUTER Now a days different types of computers are available in the market. Computers can be classified in different categories. But, on the basis of brands, three types computers are more popular in the world. • IBM (International Business Machine) computer • IBM compatible computer • Apple Macintosh Computer WORKING PRINCIPLE OF THE COMPUTER Computer accepts our data through the input device, processes and controls them through the processing device, gives the output result from output device and stores our data and information in the memory device. FEATURES OF COMPUTER The increasing popularity of computer has proved that it is a very powerful and useful machine. The power and usefulness of this popular machine are mainly due to the following features:- Speed: As you know computer can work very fast. It takes only a few seconds for calculation that we take hours to complete. It is surprising to know that computer can perform millions (1,000,000) of instructions within a 2 Introduction to Computer

second. The processing speed of computer is measured in fraction of a second which is given below: • Millisecond (KHZ) - a thousandth of a second. (Kilo Hertz) 1/1000 • Microsecond (MHZ) - a millionth of a second. (Mega Hertz) 1/1,000,000 • Nanosecond (GHZ) - a billionth of a second. (Giga Hertz) 1/1,000,000,000 • Pico second (THZ) - a trillionth of a second. (Tera Hertz) 1/1,000,000,000,000 Accuracy Computer works with a very high speed, it does not make any mistake unless the user gives a wrong instruction. Computers are 100% accurate. But if we give wrong data to the computer, it returns the wrong output or information called GIGO (Garbage In Garbage Out). Diligence Computers can work for many hours continuously without taking any rest and without decreasing its speed, accuracy and efficiency. It is free from tiredness, lack of concentration, disturbance, etc. Versatile Computer has the capacity to perform different types of work. You may use your computer to type letter, play game, watch movies, send e-mail, take online class as well as same computer can be used in offical work. Storage Computer has mass storage section where we can store large volume of data for future use. Such data are easily recalled from the secondary storage devices like hard disk (HDD), compact disk (CD), pen drive etc. Automatic Once the instruction is given to perform any task to the computer, the computer does its work automatically by itself. Reliability Computer can do its work very fast, without making any mistake and without taking rest. It is also able to store data for future use. So, it is a Smart Computer Science Book-6 3

very reliable or trustworthy machine. No Feeling Computer does not have feelings or emotion, taste, knowledge and experience. Thus it does not get tired even after long hours of work. It does not distinguish between users. No IQ Computer is a dumb machine and it cannot do any work without instruction from the user. It performs the instructions at tremendous speed and with accuracy. It is you to decide what you want to do and in what sequence. So a computer cannot take its own decision as you can. LIMITATION OF COMPUTER Computer is a man-made machine. It is very useful for us. It is very smart machine, NO IQeven though, it has lots of limitations. Some of major limitations of computers are as follows: • A computer is a machine that has no intelligence to perform any task. Each instruction has to be given to computer. • A computer cannot take any decision on its own. • Computer functions as per user’s instruction, so it is fully dependent on human being. • The operating environment of computer should be dust free and suitable. • Computers have no feelings or emotions. • It cannot make judgement based on feeling, taste, experience, and knowledge unlike a human being. 4 Introduction to Computer

Points to Know • A computer is a smart electronic device which processes raw data and produces the meaningful information. • Computer needs electric energy and our instruction to perform task. • It is also used in the science, engineering, medicine, publishing, forecasting, entertainment, designing, education and research, etc. • The word of computer is derived from the Latin word \"COMPUTARE\" which means machine that can compute. • Computer accepts data, processes them, produces output result and store data and information in memory for future use. • If we give wrong data to the computer, it returns the wrong output or information which is called GIGO (Garbage In Garbage Out). • Computers can work for many hours continuously without taking any rest and without decreasing its speed, accuracy and efficiency. • Computer has no intelligence, no remembering power, no decision power as human being, no felling and emotions. Terms to Know Instruction : Order to work something Input : Supply the data into the computer Process : Make calculation and comparison then generate result Output : Take out data and information from computer Memory : Storage device of the computer Data : Raw facts and figure collected to compute Processing : Calculation and comparison of data to get final result Information : Result obtained after processing Disk : Device which is used for storing computer information Versatile : Ability to do varieties of task Diligence : Carefully using effort for doing work in same manner Smart Computer Science Book-6 5

Worksheet Objective Questions 1. Fill in the blanks: a. The word of computer is derived from Latin word............................... b. A computer is a smart ..............................device. c. There are ............................ types of computer in the basis of brand. d. Computer accepts data through the .....................device. e. Processing speed of computer is measured in ................................. 2. State whether the following statements are true or false: a. If we feed wrong data to the computer, it returns the correct output. b. Computer can work for many hours continuously without taking rest. c. Computer can store data for future use. d. Computers have own feelings and emotions. e. Computer is not dependent on human being. 3. Write the full forms: GIGO ........................................................ HDD.................................................. CD ............................................................ IBM .................................................... 4. Match the following: Data recall for future a. Output Device Make calculation b. Storage Device Produce information and result c. Processing Device 1/1,000,000,000 d. Microsecond e. Nano second 1/1,000,000 6 Introduction to Computer

Descriptive Questions 1. Answer the following questions: a. What is computer? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... b. How does computer work? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... c. Write the features of computer. Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... d. Why is computer called versatile machine? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... Smart Computer Science Book-6 7

e. Why is computer called diligent machine? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... f. What do you mean by GIGO? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... g. How is computer a reliable machine? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... h. Write the limitations of computer other than the ones mentioned in this chapter. Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... 8 Introduction to Computer

Activity 1. Make a chart paper presentation in the classroom about 'Application of Computer'. 2. Organize an inter class debate competition in the topic: \"Without Computing Technology, we can hardly imagine our life.\" News Board 3. Prepare a news article in the topic: \"Computer is being Versatile and Diligent .........\" Smart Computer Science Book-6 9

IntroducHtiaorndwtoarCeomputer CHAPTER 2 Learn and Act... Teacher : Well ! Now, we will discuss about the physical parts of the computer. Student : Okay Ma'am, we are ready . Teacher : Hardware is similar to different organs in our body. • Keyboard, mouse and joystick are like our hands, eyes, ear, skin, etc. called INPUT hardware. • CPU is like our brain called processing hardware. • Monitor, Printer and Speaker are Output hardware. • Computer memory, hard disk, pen drive, CD and DVD are called storage. Student : Wow! Is Computer hardware like our five sense organs, Ma'am? Teacher : Yes, absolutely. INTRODUCTION OF COMPUTER HARDWARE The computer is formed by two types of components, which are hardware and software. Computer hardware can be compared with organs of human body. The physical components of computers are called hardware which we can see, touch, feel and take from one place to another place physically. Computer hardware normally also called computer devices. It is classified into different categories such as : 10 Introduction to Computer Hardware

i) Input Hardware iii) Output Hardware ii) Processing Hardware iv) Storage/Memory Hardware v) Motherboard (Backbone hardware) INPUT HARDWARE The device which is used to supply or enter data into the computer for further processing is called input device. An input device first converts input data and instructions in a suitable electrical signal (binary form i. e. 0 and 1) and then feed into the computer for further processing. Generally input device can be compared with our sense organs. The common input devices are: keyboard, Mouse, microphone, touch pad, Joystick, trackball, light pen, etc. Let's discuss them separately. Keyboard The device which is used to type the information and instruction to the computer is called keyboard. It is a common and popular input device. The layout of a keyboard comes in various styles but QWERTY is the most common layout. There are different types of keyboard having different number of keys. Maximum number of keys in the modern recent manufactured keyboard is 108. The common types of keys; alphabet keys, number keys, function keys, control keys, punctuation keys and other special purpose keys are available in the common keyboard. Mouse The mouse is a small hand-held pointing device, which is used to create graphic elements on the screen such as lines, curves and freehand Smart Computer Science Book-6 11

shapes. It is also used to run a program and pull down a menu in GUI (Graphic User Interface) based computer operating system. Usually a mouse contains two buttons, which can be used to input commands or instructions and a wheel between the buttons is used to scroll up and down. The mouse may be classified into two categories on the basis of technology: Mechanical Mouse and Optical Mouse. Optical mouse is available in wired and wireless technology. Touchpad A Touchpad is one of the latest pointing device. It looks like a small gray window about two inches wide. It is usually used in portable computer such as laptop and notebook to substitute the mouse. It has two buttons, which work like the mouse buttons. We can move the cursor on the screen by moving a finger along the pad. And we can also click by tapping a finger on the touchpad and drag with a tap in the continuous pointing scale. Trackball Trackball is an input device that is mostly used in notebook or laptop computer instead of a mouse. It is just like a turned upside down mouse. There is a ball which is half inserted and by moving fingers on ball, pointer can be moved. Since the whole device is not moved, a trackball requires less space than a mouse. A trackball comes in various shapes like a ball, a button and a square. 12 Introduction to Computer Hardware

Joystick Joystick is also a pointing device which is used to move cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The joystick can be moved in all four directions. The function of joystick is similar to a mouse. It is mainly used in Computer Aided Designing (CAD) and playing computer games. Scanner Scanner is an input device which works like a photocopy machine. It is used when some information is available on a paper and it is to be transferred to the computer for further manipulation. Scanner captures images from the source then converts into the digital form that can be stored on the disk. These images can also be edited using the image editing software before they are printed. Microphone A microphone is a peripheral input hardware. A microphone allows users to input audio into their computers and store in digital form. The microphone is used for various applications like adding sound to a multimedia presentation, mixing music, etc. You can record your own speech through the microphone. Smart Computer Science Book-6 13

Web Camera The Web camera is also an input device which is used to capture photos or videos and transfer into the computer. Specially, it is used with internet communication such as chatting, video telephony in WhatsApp, messenger, Windows live messenger, etc. Light Pen Light pen is a pointing device which is similar to a pen. It is used to select a displayed menu item, draw pictures and write text on the monitor screen. It consists of a pho- tocell and an optical system placed in a small tube. When the tip of a light pen is moved over the monitor screen and pen button is pressed, its photocell sensing element detects the screen location and sends the corresponding signal to the CPU. PROCESSING HARDWARE The device which performs the processing task such as calculation and comparison is called processing hardware. Microprocessor is a processing device which is known as the processing unit or CPU (Central Processing Unit). All the calculation, comparison and decision making are done in this unit. And all the activities of the computer such as input, process, output, storage, etc. are 14 Introduction to Computer Hardware

controlled by this unit. So, it is called brain of the computer. It is placed in the motherboard in the size of postal stamp. The CPU (Central Processing Unit) is divided into three parts: i) Control Unit (CU), ii)Arithmetic & Logic Unit (ALU) and ii) Memory Unit (MU) Control Unit The CU (Control Unit) is the most essential section of the Microprocessor which is placed between ALU (Arithmetic and Logical Unit) and MU(Memory Unit).The control Unit is a traffic management system of the computer because it checks, coordinates, directs and controls all the operations performed in different devices of the computer. So it is also called central nervous system of the computer. Arithmetic and Logical Unit (ALU) The ALU (Arithmetic and Logical Unit) is responsible to perform the arithmetic calculations and logical operations. It performs the basic operations of arithmetic calculation namely addition, subtraction, multiplication, division, etc. The logical operations involve in the comparison of two or more than two data items to check whether they are equal, greater, smaller or not equal to each other and return the value true or false. Memory Unit The memory unit of the microprocessor is also one of the most important parts of the computer. This unit stores data, instructions and result being process temporarily. The capacity of memory is measured in terms of bytes, kilobytes, megabytes or gigabytes, etc. OUTPUT HARDWARE The Output device is just reverse in function than an input device. Input device is used to feed the data into the computer and output device Smart Computer Science Book-6 15

takes out the data or information from the computer. Basically, output devices are of two types: a. Soft copy output device b. Hard copy output device SOFT COPY OUTPUT DEVICE The device which produces the electronic version of an output in audio and video form is called soft copy output device. It is in the temporary form because such output resides in the temporary memory of the computer. This kind of output is not tangible, and it can not be touched. Monitors, speakers, projector are the examples of soft copy output device. Monitor Monitor is commonly called Visual Display Unit (VDU). It is the main output device of a computer. It is also called soft copy output device because the output produced by monitor is in electronic version which we can not touch and feel physically. It forms images from tiny dots, called pixels (Picture Element) that are arranged in a rectangular form. The sharpness of the image depends upon the number of pixels. Commonly, there are of three types of monitors: CRT Monitor : CRT stands for Cathode Ray Tube. CRT is the technology used in traditional computer monitors and televisions. The CRT display is made up of small picture elements called pixels. The smaller pixels lead the better image clarity, or high resolution. So, many graphic designers are still using CRT monitors. CRT monitors are also of two types: i) Monochrome and ii) Color monitor. LCD Monitor: LCD stands for Liquid Crystal Display. It consumes less power energy and more lighter and portable than CRT monitor. It uses optical effects to convert light source into graphics patterns. 16 Introduction to Computer Hardware

LED Monitor: LED stands for Light Emitting Diodes which is the technology that uses a video display in the monitor. It converts electrical energy to light. It gives better viewing angles than LCD monitors. So, these monitors are accurate in color display than LCD and CRT monitors. Speaker Speaker is the soft-copy output device, which produces audio output. Speakers are connected to the CPU and sounds are produced with the help of sound card. Sound card is mounted on the slot of motherboard which translates digital signals that are sent to the speakers into audio sound. Hard Copy Output Device The device which produces the output result in printed form in paper or other printing media is called hardcopy output device. Hard copy output is permanent and relatively stable form of output. This type of output is also highly portable. Paper is one of the most widely used hard copy output media. Printer and plotters are example of hard copy output devices. Printer The printer is a hard copy output device, which prints information and data from the computer on to paper. Some printers produce only textual information, whereas others can produce graphics as well. There are two types of printer: i) Impact Printer and ii) Non Impact Printer Impact Printer: Impact printers are the oldest printing devices and are still in use. They use some sort of physical contact with the paper to produce an image by physically Smart Computer Science Book-6 17

striking the paper, ribbon and print hammer together. It is comparatively slow, noisy and low printing quality and more cheaper printer. Dot Matrix Printer, Daisy Wheel Printer and Drum Printer are some examples of impact printers. Non Impact Printer: Unlike impact printers, a non-impact printer forms characters and images without making direct physical contact between printing mechanism and the paper. In this printer, the print head does not make any physical contact with the paper, and no inked ribbon is required. Ink can be sprayed against the paper and then heat and pressure are used to fuse a fine ink powder or drop into the shape of a character. Ink-jet Printers and Laser Printers are examples of non-impact printers. Plotter A plotter is a pen-based hard copy output device that is attached to a computer for making vector graphics; that is images are created by a series of many straight lines. It is used to draw high-resolution charts, graphs, blueprints, maps, circuit diagrams, and other line-based diagrams. Plotters are similar to printers, but they draw lines using a pen. MOTHERBOARD (BACK BONE HARDWARE) The motherboard serves as a single platform to connect all of the parts of a computer together. It connects the CPU, memory, hard drives, optical drives, video card, sound card, and other ports and expansion 18 Introduction to Computer Hardware

cards directly or via cables. It can be considered as the backbone of the computer. Features of Motherboard A motherboard comes with following features: • M o t h e r b o a r d varies greatly in supporting various types of components. • M o t h e r b o a r d supports a sin- gle type of CPU and few types of memories. • Video cards, hard disks, sound cards have to be compatible with the motherboard to function properly. • Motherboards, cases, and power supplies must be compatible to work properly to- gether. STORAGE HARDWARE Storage device is a computer hardware that is used for storing, porting or extracting data, audio, video, image and program files. It can hold and store information both temporarily and permanently. It may be internal or external to a computer. There are two types of storage hardware: i) Primary storage hardware and ii) Secondary storage hardware Smart Computer Science Book-6 19

Points to Know • The physical components of computers are called hardware which we can see, touch, feel and take from one place to another place physically. • The devices which are used to supply or enter the data into the computer for further processing is called input device. • The mouse is used to create graphic elements on the screen such as lines, curves and freehand shapes. It is also used to run a program and pull-down the menu. • Light pen is a pointing device which is similar to a pen. It is used to select a displayed menu item and draw pictures on the monitor screen. • The device which performs processing task such as calculation, comparison and manipulation is called processing device. Microprocessor is a processing device. • All the activities of the computer such as input, process, output, storage etc. are controlled by CPU. So, it is called brain of the computer. • The logical operations involve comparison of two or more than two data items to check whether they are equal, greater, smaller or not equal to each other. • CU checks, coordinates, directs and controls all the operations performed in different devices of the computer. So it is also called central nervous system of the computer. • The device which takes out the data and information from the computer in the video, audio and printed form is called output device. • The device which produces the electronic version of an output in audio and video form is called soft copy output device. • The device which produces the output result in printed form in paper or other printing media is called hardcopy output device. • Impact Printers use some sort of physical contact with the paper to produce an image by physically striking the paper, ribbon and print hammer together. • Ink can be sprayed against the paper and then heat and pressure are used to fuse a fine ink powder or drop into the shape of a character. • The motherboard serves as a single platform to connect all of the parts of a computer together. It can be considered as the backbone of a computer. • Storage device is a computer hardware that is used for storing data files and objects temporary and permanently. 20 Introduction to Computer Hardware

Terms to Know CAD : A System combination of hardware and software that enables engineers and architects to design everything Pixel : The smallest element of a picture represented on the screen Digital : Device which works in the basis of digits (0 and 1) Photocell : Sensors that allow you to detect light. They are small, inexpensive, low- power, easy to use and don't wear out. Chatting : Exchange messages with friends using internet Interface : Program enabling a user to communicate with a computer Video telephony : Real-time audio-visual communication with each other Messenger : Computer program that helps for messaging others instantly Motherboard : Physical arrangement in a computer that contains the computer's basic circuitry and components Compatible : Able to adjust together without problems or conflict Optical Disk : An electronic data storage medium that can be written and read using Blue print low-powered laser beam technology : A technical drawing, an architectural plan, or an engineering design, using a contact print process on light-sensitive sheets Port : A port is an endpoint of communication. Physical as well as wireless connections are terminated at ports of hardware devices Connectors : An electromechanical device used to join electrical terminations and create an electrical circuit Peripheral : Devices connected to a computer system in order to make work Slot : A long narrow slit in motherboard for expansion card to be connected IDE Connectors : Standard type of connection place for storage devices in computer CPU Socket : CPU house that forms the electrical interface and contact with the CPU Heat Sink : Heat exchanger that transfers the heat generated by an electronic device to a fluid medium or often air Porting : The process of adapting software for the purpose of achieving some form of execution in a computing environment Smart Computer Science Book-6 21

Worksheet Objective Questions 1. Fill in the blanks: a. Computer hardware can be compared with......................... of human body. b. An input device first converts input data and instruction into ............................. c. The common layout of keyboard is.................................... d. Track ball is just like........................................................mouse. e. Scanner works like a ...................................machine. f. ...............................is a processing device. g. Touch pad is a ...........................device. h. Storage device holds and stores information both ................... and ...................... i. The ........................... serves as a single platform to connect all the parts of a computer together. j. Plotter is a ..................... hard copy output device. k. CU is placed between ........................... and ........................ l. Logical unit always returns ..................... and ......................... 2. Write 'T' for true and 'F' for false statement: a. Microphone is an output device. b. CPU is the brain of computer. c. The control unit is a traffic management system. d. Monitor is also called VDU. e. Printer is a soft copy output device. f. Touch pad is also called pointing device. g. Dot matrix is an impact printer. 22 Introduction to Computer Hardware

h . The sharpness of the image depends upon the number of pixels. i. Motherboard supports a multiple type of CPU and memories. j. The smaller pixels lead the better image clarity, or resolution. k. The electronic version of an output is known as soft copy output. l. Touch pad is a substitution of a mouse. m. Peripheral devices attached to the motherboard must be compatible. 3. Write the full forms: VDU....................................................... ALU ....................................................... GUI....................................................... CPU.......................................................... CAD....................................................... LCD.......................................................... CD..........................................................CU............................................................ MU......................................................... CRT.......................................................... LED ....................................................... Pixels ..................................................... 4. Match the following: a. Input Impact b. Output Store data c. Processing Print in paper d. Memory Non impact e. Hard copy output Plotter f. Soft copy output Scanner g. Ink Jet Printer CPU h. Dot matrix Printer Sound Smart Computer Science Book-6 23

Descriptive Questions 1. Answer the following questions: a. What is meant by processing device? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... b. What is computer hardware? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... c. What do you mean by input device? Give three examples. Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... 24 Introduction to Computer Hardware

.................................................................................................................................... d. What is the function of mouse? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... e. What is light pen? Why do you use it? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... f. Why is CPU called the brain of computer? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... Smart Computer Science Book-6 25

g. What is the function of CU? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... h. What does logical operation involve in? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... i. What do you mean by output device? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... j. Differentiate between hardcopy and soft copy output. 26 Introduction to Computer Hardware

Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... k. What is scanner? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... l. Why is mother board called the back bone of the Computer? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... m. What do you mean by storage device ? Ans.............................................................................................................................. Smart Computer Science Book-6 27

..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... n. What do you mean by vector graphics? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... o. Why is CU called traffic management system? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... p. What is the role of ALU? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... 28 Introduction to Computer Hardware

..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... q. What is plotter? Why is it called vector graphics printing device? Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... r. What is keyboard? Write the working principle of Keyboard. Ans.............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... s. What is the role of memory unit of CPU? ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... Smart Computer Science Book-6 29

Activity 1. Visit the computer Lab and perform the following activities: a. Make a computer ready for experiment and get help of a teacher for this experiment or watch the related video in YouTube. b. Recognize the major external components of a computer as mentioned in the chapter. c. Open the CPU cabinet and recognize details as given in the picture of motherboard in this chapter as well as other internal hardware components. 3. Organize a chart paper presentation in the class room about 'The parts of moterboard and their functions'. 30 Introduction to Computer Hardware

Memory Device CHAPTER Learn and Act... 3 Ritu : Excuse me Ma'am ! As we remember and recall the matters of past, can computer also do so? Teacher : Of course! Computer also has a device having the capacity to recall the previous activities called the memory device. Ritu : We may not recall all the past matters. Can computer recall all of it? Teacher : Computer has two types of memory devices: Primary and Secondary. Once you store matter in the secondary memory, you can recall until you remove them from there. But, if your matter is recorded only in the primary memory, it is stored as long as your computer is on. Let's discuss in detail. INTRODUCTION OF MEMORY 31 The hardware which holds our data, information and programs for future use or current use is called memory hardware or device, simply, it is called computer memory. The CPU of the computer can easily access the data information and programs from the computer memory. Basically, memory hardware is classified into three categories: Smart Computer Science Book-6

(a) Primary Memory (b) Cache Memory (c) Secondary Memory Primary Memory Primary memory is the main memory or internal memory which is directly accessed by the CPU(Central Processing Unit). It allows a processor to access running programs and currently processed data stored in a memory location. Its speed of data accessing is faster than the secondary memory because it is made by IC (integrated Circuit) or semiconductor device. But it has limited storage capacity. It is also used to store such programs which are useful to start up the computer. The Primary memory is divided into two subcategories RAM and ROM. RAM (Random Access Memory) RAM is the internal memory of the computer for storing data, programs and processes result. It is also called the 'main memory' because CPU directly access it for processing task. It is read/write memory which stores data until the machine is working. Data in the RAM can be accessed randomly so that it is high speed memory. As soon as the machine is switched off or if there is a power cut, data is erased from this memory, so it is also called volatile memory. Hence, a backup UPS(Uninterrupted Power System) is often used with computers. ROM (Read Only Memory) ROM stands for Read Only Memory. The memory from which we can only read but cannot write on it. This type of memory is non-volatile. The information is stored permanently in 32 Memory Device

such memories during manufacture. A ROM stores such instructions that are required to start a computer. This operation is referred to as bootstrap. ROM chips are not only used in the computer but also in other electronic items like washing machine and microwave oven. SECONDARY MEMORY The memory which is used to store data, information and programs permanently for future use is called the secondary memory. In this memory, data is permanently stored even if power is switched off. So, it is also called non-volatile memory. This type of memory is also known as external memory. It is slower than 'main memory'. CPU directly does not access these memories. They are accessed via input-output routines. Contents of secondary memories are first transferred to main memory then CPU can access it. Hard disk, pen drive, CD-ROM, DVD, etc. are the examples of the secondary memory. Hard disk Hard disk is the main secondary storage device of the computer. It is also called mass storage device. It uses 2-4 metallic disk (platter). It is usually made of aluminum. Both sides of the disk is used for storing data except the upper side of the uppermost disk and lower side of the lowermost disk. The data storing surface is coated by magnetic oxide. Each data storing surface contains separate read/write head. During data read/write process, platter rotates at the rate of 3600-15000 rpm (revolution per minute). Hard disk is also known as hard drive because both data storing disk and data read/write components are combined together. It has the storage capacity of few Mega Bytes (MB) to Tera Byte (TB). Smart Computer Science Book-6 33

Pen Drive Pen Drive is a flash memory. It is mainly used for transferring data. It has faster reading/writing speed compared to magnetic memory. Pen drive has storage capacity of a few MB (Mega Byte) to GB (Giga Byte). A pen drive is also called plug and play device because it can be connected with the computer through USB (Universal Serial Bus) port. Optical Storage Optical storage is a type of secondary storage in which data are written and read with a low powered laser beam technology. Compact disks (CDs), Digital Versatile Disks (DVDs) and Blu-ray Disks (BDs) are popular example of optical storage. Optical storage are made by plastic with laser assembly. It is coated with thin metal or some highly reflective material. These are light, portable, cheap and storage capacity is moderate, so these are used for distributing multimedia applications and software. CACHE MEMORY Cache memory is a very high speed semiconductor memo- Cache Memory Primary Secondary ry which can speed up CPU. CPU Memory Memory It acts as a buffer between the CPU and main memory. It is used to hold those parts of data and program which are most frequently used by CPU. The parts of data and programs are transferred from disk to cache memory by operating system, from where CPU can access them. In modern CPU, Cache memory is built inside the CPU. 34 Memory Device

Points to Know • The hardware which holds our data, information and programs for future use or current use is called memory hardware or memory device. • Primary memory is the main storage space of the computer which holds data and instructions currently using and needed to startup the computer. • RAM holds only those data and instructions on which computer is currently working. • As soon as the machine is switched off or if there is a power failure, data is erased from RAM. So, it is also called volatile memory. • ROM stores such instructions that are required to startup a computer. • The memory which is used to store data, information and programs permanently for future use is called secondary memory. Hard disk, pen drive, CD ROM, etc. are examples of secondary memory. • Both sides of the Hard disk is used for storing data, except the upper side of the uppermost disk and lower side of the lowermost disk. • Hard disk is also known as hard drive because both data storing disk and data read/write components are combined together. • A pen drive is a flash memory which is connected with the computer through USB port. • Optical Disk is coated with a thin metal or some other highly reflective material. Laser beam technology is used to read and write the data in the disk. • Cache memory is a very high speed semiconductor memory which can speed up CPU. • Cache is used to hold those parts of data and program which are most frequently used by CPU. Smart Computer Science Book-6 35

Terms to Know Flash memory : A type of re-programmable memory that retains information even with the power turned off Optical Disk : An electronic data storage medium that can be written to and read from using a low-powered laser beam Laser Beam : A beam of radiation produced from a laser Buffer : A region of memory to hold data that is waiting to be transferred Instruction : Command given to a computer to carry out a particular operation Semiconductor : Kind of electronic circuit element Register : A mechanical component which automatically records certain data. Volatile : Does not remain data when electrical power is turned off or fails Disk : Device used to store data permanently Magnetic Oxide : A chemical substance applied to disk Platter : The circular disk on which magnetic data is stored in a hard disk drive Hard-Drive : A disk drive containing a hard disk Worksheet Objective Type of Questions : 1. Fill in the blanks: a. ....................... .............................. is the main memory of the computer. b. The information is stored permanently during .................................................... in ROM. c. CPU accesses secondary memory via .............................................. routines. d. The data storing surface of hard disk is coated by ................ ..................... 36 Memory Device

e. Pen drive is a ...................................... memory. f. CD is an .......................................disk. g. Cache memory is a high speed ..................................................... memory. 2. State whether the following statements are true or false. a. Hard disk is also known as mass storage device. b. Secondary memory is a non volatile memory. c. ROM is a read and write memory. d. CPU directly access the data, programs and informations from the RAM. e. USB port is used to connect pen drive with computer. f. Cache memory acts as buffer between CPU and main memory. 3. Write the full forms a. CPU.............................................. b. USB ........................................................ c. CD ................................................ d. ROM ....................................................... e. BD ............................................... f. RAM ........................................................ g. DVD ............................................ h. CD-ROM.................................................. i. CD-R............................................. j. CD-RW...................................................... k. MB............................................... l. GB ........................................................... m. TB.............................................. n. rpm......................................................... Smart Computer Science Book-6 37

4. Match the following Group 'A' Group 'B' a. RAM Buffer b. ROM Successor of DVD c. Cache memory Volatile d. Blu-Ray disk None-volatile e. Pen drive Mass storage f. Optical disk Flash Memory g. Hard disk CD-ROM Descriptive Questions 1. Answer the following questions: a. What is computer memory? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... b. What is RAM ? Why is RAM called volatile memory? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... 38 Memory Device

..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... c. What is the function of ROM? Ans: ............................................................................................................................ ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... d. What type of memory is called the primary memory? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... e. What type of memory is called the secondary memory? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... Smart Computer Science Book-6 39

..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... f. Why is hard disk called hard drive? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... g. What is hard disk? Why is it called mass storage device? Ans:.............................................................................................................................. ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ ................................................................................................................................ h. What is an optical disk? Ans:............................................................................................................................. ..................................................................................................................................... 40 Memory Device

..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... i. What is pen drive? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... .................................................................................................................................... j. What is the function of cache memory? Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... k. Differentiate between RAM and ROM. Ans:............................................................................................................................. ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... ..................................................................................................................................... .................................................................................................................................... Smart Computer Science Book-6 41

Case Study and Application-based Questions 1. Rampati Chaudhary has typed her project work in the computer. a. Where is typed information being stored? Ans:............................................................................................................................. b. If she wants to store information permanently in her computer for future use, which device should she use? Ans:............................................................................................................................. 2. The given informative image shows the computer is going to startup: a. Where is such information stored? Ans:............................................................................ b. Can you change such information? Mention your logic. Ans:............................................................................................................................. ..................................................................................................................................... .................................................................................................................................... 3. Ritesh Chaudhary is the owner of a video recording and distribution company. He has to sell music videos in the market; which device is more reliable for Ritesh to distribute the music videos? Ans:.............................................................................................................................. 4. Taniya has to print her project work but she doesn't have printer connected to her computer. She thought to print from her friend Rampati's printer. How would she take her project work on her friend's computer? Mention your most effective logic? Ans:.............................................................................................................................. 42 Memory Device

5. Muktar Alam has to buy a computer for heavy graphics design task, hence he needs high speed computer. Which is the most significant memory device for this requirement? Mention your logic. Ans:............................................................................................................................. ..................................................................................................................................... 6. Shikha Gupta has typed her project work on her computer. Suddenly, she faced power fluctuation problem, hence the computer restarted. After restarting the computer, she could not get her typed matter. a. Why didn't she get this typed information? Mention your logic. Ans:.............................................................................................................................. b. To get the typed information after facing such problem, what could she do? Ans:.............................................................................................................................. Smart Computer Science Book-6 43

Activity 1. Visit the Computer Lab and perform the following activities with the help of your teacher: a. Watch the respective YouTube video associated with this chapter. b. Open the CPU cabinet and recognize all the memory devices and respective drive. c. Take out the motherboard and separate all the components as possible and recognized RAM and ROM. d. Reassemble all the parts you separated. 2. Divide the class into the two groups of students to organize the Chart paper presentation on the following topics: a. Primary memory b. Secondary memory Project Work 1. Write an article for your school's news bulletin on the topic 'Role of Computer Memory' . 44 Memory Device