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INTRODUCTION TO COMPUTERS

1. 3 columns with titl mark each 3 marks nina SD 1 mark ii State the expression that would be used to obtain I Monday s profit 2mks B3 C3 II Total income SUM B3 B7 OR B3 B4 B5 B6 B7 HI 18 a b Highest expenditure MAX C3 C7 Subtract Oil 1 from 1001 1001 111 0010 0010 10 Using two s complement subtract 7 from 4 and give the an notation POP Step 1 Write it as 4 7 RA Step 2 Change the values to 8 mg 4O in decimal 4 marks 0000011 Step 3 Get the Ones complement of the second value 11111000 Step 4 Add 1 to the One s complement to get Two s complement 11111000 amp l S y S 11111001 Step 5 Add the binary equival ro value to the Two s complement of the second value 00000100 11111001 111111 111111012 ep 1 Convert 91B16 to decimal amp Q Convert 91Bis to octal 3 marks 16 16 16 9x16 1x16 11x16 2304 16 11 2331 10 Step 2 Convert 233110 to octal ii 376s to Q Step 1 6S to decimal 87 8 3x8 7x8 6x8 ON 192 56 6 25410 Step 2 Convert 25419 to hexadecimal mm iii 9 6259 to binary 4 marks 1 R Q 4 250x2 0 50 0 0 50x2 1 00 gt 1 0 625 19 1012 9 625 19 1001 1012 19 a i ii ili iv
2. SECTION A 40 marks Answer all the questions in this section 1 How is a point of sale terminal used in a business organization 2 mks It can be used for pricing the different types of commodities 3 For adding totals of purchase amp calculating Ra e For receipt production It can be used as a bar code reader Fore checking stock levels stock control 2 Distinguish between compiler and int 2 mks A compiler translates t ram at once as a unit before execution can begin An Interpreter translat s one imstruction of the source program at a time The translated instruction is 1 y obeyed before the next instruction can be translated An interpr ates the program each time it is needed for execution compiled wa be saved on a storage media and run when required For terpreter syntax errors are reported amp corrected before the execution can continue For a compiler syntax errors are reported amp corrected after the source code has been translated to its object code equivalent 3 Explain why computers use binary numbers in data representation 2 mks Data is stored in computers in binary form The computer s CPU carries arithmetic amp logical operations by binary numbers This is because binary numbers has only two digits 0 amp 1 which make it suitable for O What is meant by the term dry running as used in program opment 2 mks A method of checki
3. a b 1 4 0 44241 8 4 24 1 1 4 0 7 15 1407Fi6 State one use of hexadecimal notation in a computer usa Helps to manage long binary digit properly Helps to improve the processing speed and o Convert 767 to hexadecimal equivalent o ry usage 2 mks Step 1 Convert 767s to decimal 87 g 8 4O 7 6 7 7x8 6 x 8 TRB 448 48 10 Ne 50310 to hexadecimal 503 Rem 16 31 7 16 1 15 8 9 7678 1 F716 Use One s compliment to solve the following the following sum 519o 2mks 2 5 Rem 2 2 1 2 1 0 1 1 Perform the following conversions a 341o to Binary g 34 19 1000102 2mks b 7 12510 to binary 2 7 Rem 2 3 1 2 1 1 1 1 111 0 12 x2 0 250 gt 0 0 20 x2 0 500 gt 0 0 500x2 1 000 gt l 111 001 athe c 101101 toa D 25 d zo oo ee 1 0 1 1 0 1 1x25 1x29 1x25 1x2 32 8 4 1 45 10 2mks Imk d 10 11 to decimal 1x2 Ox2 1x2 1x2 2 0 4 2 0 5 0 25 e 20 216 to decimal 16 16 16 32 0 125 32 12310 f TABi6 nS 2x16 0x16 z 16 16 16 7 A 2 7510
4. Compact Disk Rewritable CD RW 34 LS 120 super disk Digital Versatile Disk DVD Optical card Optical tape b Give two advantages of a digital Versatile Disk over a normal Compact disk DVD has a larger storage capacity than a CD Gy mks a State the two types forms of computer Ow a evices in a computer A DVD offers better data storage quality Softcopy Hardcopy b List any four examples of outp Monitors Printers Ww und Q e g speakers N units Plotters Sound cards Digital projectors Computer output on microforms COM Storage devices 35 c Identify three Functions of computer devices Transmit the intermediate amp final results to the users Convey messages e g error messages to the operators Provide immediate response to queries Convert the coded results produced by the computer to human readable form a State one function of the screen monitor Used to display the results of all the data that has been wpe the computer 5 It converts machine coded outputs results AS or into a form that can be understood by people b Show two differences between a C r and a flat panel display CRT monitor uses a cat y tuibe to display information while a flat panel does not CRT has a prot while a flat panel does not Flat panel O light amp easily portable while CRT s are heavy Tc lay a wide range of colours
5. 7x16 10x 16 11x16 1792 160 11 196310 2mks V1 V1 3mks 2mks g 0 111011 010 to Octal 2mks 000 111 0 11 1O 1 0 4 2 1 2 1 2 1 2 O 73 28 SS O N gt Convert 57 4 to its Octal equivalent 2mks a i gS 8 7 8 7 eS y 0 4x8 3 2 3 0 2x8 16 gt 1 0 31s 71s 71 318 11 a Perform the following Binary arithmetic i 11100111 00101110 1mk 11100111 00101110 1 00010101 100010101 gt 1 mk ii 10101 11042 LS Imk 101012 1102 11112 b Use Two s complimen 101 from 1000 2mks Step 1 change the values to 8 binarygdigits 000010002 0 Step 2 Add the bi alent of the first value to the Two s complement of Q value At 11111011 1 0000001 1 10000001 12 2mks 12 Step 1 Step 2 Convert 7A E46 to a decimal number 16 16 16 7 A E 7x16 12x16 1x16 3840419241 403310 2 4033 Rem 2 2016 1 2 1008 0 l2 50 lo 2 252 Jo l2 126 lo 2 63 0 2 31 2 7 1 2 3 1 7 1 1 1 1 403319 111111000001 2mks 14 ii iii iv Write the following abbreviations in full 4mks BIT BCD ASCII EBCDIC Binary digit Binary Coded Decimal American Standard Code for information Interchange Extended Binary Coded decimal Interchange Code
6. DATA PROCESSING 1 With an aid of a diagram explain the stages of the data processing cycle 6mks Data Collection Output of information e Data collection involves getting the data facts needed for processing from the point of its origin to the computer Data Input the collected data is converted into machine readable form by an input device and send into the machine Processing is the transformation of the input data to a more meaningful form information in the CPU Output is the production of the required information which may be input in future 2 Clearly differentiate between data collection and data capture Cemo Data capture is the process of obtaining data in a computer sensible form for at the achine sensible form for input Data collection involves getting the amp to the processing centre transcribing it converting it from one mediu D er and finally getting it into the computer point of origin the source document itself is pr 3 Outline the 5 stages of data Collection 3mks onversion i e conversion of data from one medium to another Input validation Sorting Explain the relevance of the term garbage in garbage out GIGO in reference to errors in data processing 1mk b a b The accuracy of the data entered in the computer directly determines the accuracy of the information given out Give and explain two transcription and two computat
7. Are small in size oc Are more e K Are more D do S Q can be used for many different tasks ing various functions than the early mainframe computers a Identify and explain five areas where computers are used to process data 10 mks Supermarkets For stock control i e records of what is in store what has been sold and what is out of stock For calculating customer s change For production of receipts It can be used as a barcode reader Banks Manage financial transactions through the use of special cash dispensing machines called ATMs used for cash deposit amp withdrawal services Processing of cheques For preparation of payrolls Better record keeping amp processing of documents LS O Provide electronic money transfer facilities A Homes sic playing computer games Entertainment e g watching movies p For storing personal information g s For calculating amp keepi i Industries To monitor and o ustries processes through the use of robots For manag Q i e to keep track of elders bills and transactions r ad ent purposes which enable an industry to attack more customers Poli ations Matching analyzing amp keeping databases of fingerprints For taking photographs amp other identification details For record keeping For face recognition scene monitoring amp analysis which help the police carry out criminal investigations speedily 19 Identify three advant Transport ind
8. Some pack capabilities which will require the user to develop them further is AY forget the commands to use the package especially if it is not used freq b i Explain why a value such as 6112334445555 may be displayed as when typed in a cell on a spreadsheet 2 mks ii How can the problem in b i above be corrected By increasing the column width c With reasons briefly describe the most appropriate type of printer or output device for the output of 6 mks i Customer invoices on multi part stationery Dot matrix printer or any impact printer It produces sharp impact on both original land and the copies 9 LaserJet Printer or any impact printer it is RA a 9 Dot matrix printer It is cheaper for iii Detailed engineering designs 49 Plotters Q Have appropriate faealities for drawing amp graphical output 20 a Distinguis Weng e following pairs of terms and data validation ii Letters to customers quality printouts ting is checking data manually to ensure ascertain that it has been transcribed written out correctly Validation involves subjecting data to checks built in a program to check for its appropriateness or integrity before it is processed ii Data encryption and passwords Encryption mixing up distorting or changing of data being transmitted over a network to prevent unauthorized disclosure A password a secret code used to
9. a Wha hescomputer Motherboard Address bus it conveys address arries the address of the memory location or device to be acted on by the This is the electronic board where all electronic components such as processor memory chips BIOS bus connections etc are assembled b State any four components found on the computer motherboard Processor CPU SIMM DDR sockets Memory chips 19 20 BIOS Interface chips Buses a What is a Drive A drive is a computer device for reading data from or writing data into a storage media V f a storage device used by e g a tape or disk b State any two types of computer drives giving a each Hard disk drive HDD isk drive FDD CD ROM drive iS ROM drive Tape drive 3 mks Zip drive USB port for flas Cost of implication Capacity of storage systems b State three different examples of auxiliary storage devices Magnetic tape Floppy disk 21 22 Cassette tapes Hard disk Zip disks Jazz disks Flash disks Video Compact Disk VCD Digital video Disks DVD s Punched cards AS me WAO or Optical discs e g Compact Disks LS 120 AN al card optical tape Using examples distinguished between S 2 mks QS directly by the CPU while secondary storage is i Primary and secondary Primary storage devices not ii Fixed and rem e d
10. iii Fibre optic cables is signals fro O o another on the network Advantag amp o Q to electromagnetic interference and eavesdropping is fast and supports high bandwidth ade ansparent glass and uses light to transmit data o It has low attenuation hence a long distance can be covered o Itis small amp light Disadvantages o Difficult amp expensive to install o Once broken it is difficult amp expensive to repair iv Wireless microwave radio transmission 3mks e In wireless transmission no physical connections are used to transmit data from one point to another Instead a transmitting antenna amp a receiver aerial are used to facilitate the communication Advantages o wireless networks can span large geographical areas easily o Can be used in very remote areas that do not have high Gy infrastructure like telephone lines o Flexible A Disadvantages o The initial cost is very high o Itis relatively difficult toe abl r configure Explain the function of the fo ork devices i Network interf ce c NIC NIC cre sical link between the computer and the transmission media ii Gat Q provide access to the Wide area networks amp the Internet iii ridge This is a network device that selectively determines the appropriate network segment for which a message is meant to be delivered iv Repeater A repeater receives a weak signal on the network cleans and amplifies it for transm
11. A word processor allows mail merging which makes oe produce similar aphics and formatting for use in all documents of 2mks sip Dine and makes creating of new documents easy It ensures that there is consistency between the documents being created Explain the difference between overtypes and insert mode in word processing 2mks Type over deletes the current text at cursor position and inserts new text Inserting pushes the old text away as new text is inserted at cursor position Veronica tried to retrieve a document file following all the steps correctly The filename did not appear in file list box State three causes for this 3mks The file may not have been saved The file may have been deleted The file may be located in a different folder from the one she Was mying to retrieve from or may have been moved The file may have been destroyed by a computemvifus Mwikali selected a paragraph in word processing Explain what happened after pressing the following keys on the keyboard 3mks i CTRL B Changes the paragraph ito bold removes bold from paragraph il CTRL A the whol document is selected ili CTRL U the sel cted text is underlined removes underline from the selected text Precisely explain the role of the following editing features of a word processor 3mks i Find and replace To find words that you want replaced by others il Undo and redo Undo reverses the previous latest ac
12. b Explain what the following DOS commands will do when executed A gt copy B 2 marks Copy all the files from drive A to drive B C gt ERASE DOC 2 marks Delete all files with extension DOC from drive C B gt DIR P BAT 2 marks Display all the files beginning with P and have extension of BAP in drive B A gt MD EXAMS 2 marks Creates a directory called EXAMS in drive A i With the aid of a diagram explain hierarchical tree network topology 3 marks 50 e It is connected in such a way that nodes are in different levels of control such that higher nodes control those below them e A child node has only one parent but a parent node can have more than one child e The child nodes can only be accessed through the parents amp topology A Advantages ef Provides centralized control ii List two advantages and two disadvantages ical network 4 marks Enhances data security amp aX Easy to isolate faults Easy to add and remove nodes If a non Y s partial communication is still possible Disadvantages vement along the branches q node fails the child nodes are inaccessible Difficult sophisticated to implement in a wide area network a Name and explain the function of the keyboard keys represented by the following symbols Tab key 2 marks Used in Word processors to move certain text or the cursor at set intervals on the Same line to
13. s Basic salary gross salary and all benefits 15ymks sar gt ENTER Name Years Basic salary Sales Experience gt YES 10 yrs ioe ma 0 1 Sales gt YES 200 0007 Bonus Sales 0 15 Sales YES Bonus Sales 0 1 Between 100 000 a Bonus Sales 0 05 Basic PRINT Name Basic Y Bonus E salary i SYSTEMS DEVELOPMENT 1 What do you mean by a system 2mks A system is a set of items equipments procedures programs or techniques amp people working jointly with an aim of achieving common goals 2 Differentiate between soft systems and hard systems 2niks In Soft systems goals and objectives are not clearly defined M hard systems goals amp objectives are clearly defined and the outcomes from thesprocesses of the systems are predictable Soft systems are usually the human activity Systems their boundaries keep on changing Smks 3 Explain five characteristiGjofa system 5mks Holistic thinkings system contains a set of interacting elements However in holisticahinking a system is considered as a whole unit Purpose a system must be designed to achieve a specific predefined objective System boundaries and environment the components of each system should operate within a specific framework limits or space The system receives inputs from amp communicates its outputs to the environment Subsystems A system does not exist alone but it is made up of different co
14. 1 Differentiate between data security and data integrity 2mks 2 a b Data security the protection of data amp information from accidental or intentional disclosure to unauthorized person or from unauthorized modification Data integrity the accuracy amp completeness of data entered in a computer Define integrity the accuracy amp completeness of data entered in a computer Define the term Computer crime 2mks The use of computer hardware or softwaresfor illegal activities e g stealing forgery defrauding etc A deliberate theft or criminal destruction of computerized data Committing of illegal acts using a Computer or against a computer system Explain the meaning 0f each of the following with reference to computer crimes 7mks 1 Gracking use of guesswork over and over again trying to look for weak access points in software in order to get access to data amp information ii Hacking Breaking of security codes and passwords to gain unauthorized access to a computer system iii Tapping Listening to a transmission line to gain a copy of the message being transmitted iv Piracy Making illegal copies of copyrighted software data or information i e copying of software illegally v Data alteration Illegal changing of stored data amp information without permission with the aim of gaining or misinforming the authorized users Alteration changes the information inferences from the data
15. 1 mk A Cr S QS Es ae c Give three directories or subfolders 3 mks hat are not required currently until they are needed again the files of one program separately from the files of another program It allows each user to keep his her files separately even if all the users are using the same systems 18 The Hierarchical system represented below shows how a school organizes its files Study it and answer the questions below The F2 directory has the files chs y tricts xls and the tribe mdb Write down the path of accessing the Distri AASCHOOL EX AMS FADistrict xls 2 mks 19 a i Explain Q of backup 2 mks E e of duplicate copies of data or programs from the hard disk into storage N in case the system fails or originals are corrupted or lost the data can be reconstructed from the backups This is used to protect data from accidental erasure or hardware problems ii Explain two methods you can use in windows to back up data into a storage device 2 mks Using copy and paste commands on the Edit Menu Using the send to command on the file menu Using the backup facility to compress the data into another disk b Identify two reasons why a user needs to know the space avait Go storage in the hard disk 20 21 To know the amount of data that can be stored 1 k To know how much space is left in the gt se a new programs needs to be installed To detec
16. amp accurate information Scene monitoring amp an A the police in arresting traffic offenders and criminals Library m ent systems 2mks rind records and stock management Trac overdue books Suggest how computers may in future be made more user friendly for persons that are a Blind Imk Development of Braille keyboards or engraved keyboards Computers can be installed with talking software i e can store voice patterns of the user b Without hands Use of voice activated commands Computers can be installed with powerful multimedia system amp speech recognition devices 12 Give at least four reasons why a firm may decide to comput its Operations z Handling of errors easily A Easy storage and retrieval of a Increased efficiency Higher quality work Reduced cost QS amp IMPACT OF ICT ON SOCIETY Identify four problems associated with the introduction of computers in a society 4mks o Job displacement and replacement o Computer crimes e g piracy fraud hacking o Health effects e g repetitive strain injury eye problems o Cultural effects and immorality DVD s pornographie lterature on the Internet Distinguish between job replacement and job displacenient inyreference to Computerization 2mks e In job replacement the unskilled workers may be replaced with the skilled ones In job displacement some employees maybe displaced moved
17. hence enquiries or file interrogation is possible 19 There is user computer dialogue established through the terminals connected to the host central computer Avoids duplicating of software The user of the system can benefit from the computer facilities through remote terminals Disadvantages of time sharing Te user has no control over the central computer OX N Response time is high when the users are man Not reliable as regards to the security amp m A school bought a computer system The items supplied include a 800 MHz processor 64 MB of RAM as eakers a monitor a keyboard a 120 GB hard disk a floppy disk drive a C Re 2 an operating system a BASIC interpreter and the following package spre ts graphics word processor art database and games a List three input devices from the given specifications write drive a mouse a modem an inkjet printer and a joystick The software supp Keyboard Mouse Joystick b Explain the meaning of the following i ii Gii c i ii 800 MHZ 800 megahertz 800 million hertz It s the processing speed of the CPU in Megahertz It means that the system cock has a speed of 800 million oscillations per second 2 mks 64 MB of RAM amp This is a measure of the storage capacity of the primary MOWRanom access Memory RAM in megabytes A 120 GB hard disk Q storage capacity in gigabytes 1
18. i Smoking Smoke particles settle on storage devices and may scratch them during read write operation It can cause fire It deposits ash on devices causing malfunction It affects the health of other users ii Eating foods amp Food particles may fall into the moving parts of the computer ge them SS Distinguish between real integer and characte Q as used in programming Real Used for numeric values th tS fractions decimals Has a higher range than i Integer CA Used fi mbers lower range than real Characters Used for alphanumeric control signal graphical character Character uses fewer bits than a real or integer The cells K3 to K10 of a worksheet contain remarks on students performance such as very good good fair and fail depending on the average mark Write a formula that can be used to count ALL students who have the remark very good 3 mks COUNTIF K3 K10 Verry Good a State the purpose of registers in a computer system 1 mks They act as high speed storage locations They are used to Pl instructions S s S temporarily just before and after processing b Name two multiprogramming operating s Linux 7 Microsoft windows 98 z UNIX QS Microsoft windows 2000 OS 2 2 Microsoft vell Q Mic Windows XP e Macintosh OS a A serial file comprises of records placed in positions 1 to 10 State the
19. 1101001 011 1110111 1101 ii 1001011 011 111 111 1001011 011 111 111 1000011 100 f 4 a nanan machine and assembly language 2 mks chi uage uses machine codes binary digits that consist of 0 s amp 1 s whereas asse language makes uses mnemonic codes symbolic representations of the machine code b State the type of translator necessary for a program written in 2 mks i High level language Interpreter or compiler ii Assembly language Assembler Briefly explain the purpose of the following types of program documentation 3 mks a User manual This is a manual provided for an end user to enable him her use the program It is program but needs to be Ae reminded about a particular point or Aa about a particular applicable in user oriented documentation b Reference guide I is used by someone who already knows ho feature c Quick reference guide This is a single sheetgor c mall enough to fit into a pocket which the user may keep handy x Q ommon tasks carried out with as program Stat tures of a user friendly program 2 mks so and recovery Good screen display Validation of input Comment statements Indentations Self descriptive variables Menu driven Online help a a Distinguish between labels and formulae with respect to spreadsheets 2 mks Labels are text consisting of alphanumeric characters while a formula i
20. 4 binary digits to represent aia decimal digit b Number 4 O Write the number 45119 in BCD notation AS Imk 97 BCD equivalent 0100 0001 45119 0100010100014 NA 14 Arrange the followi 2 in ascending order of size BY TE NIBBLE 2mks V Nibble gt Byte File 15 State two health issues that may result from prolonged use of computers 2mks e Harmful radiations that cause damage to eyesight eye problems e eyestrain eye fatigue Headaches Repetitive Strain Injury RSI i e arm strain wrist strain finger deformation Back strain S S gt Q QS ae V SECTION B 60 MKS ANSWER QUESTION 16 AND ANY OTHER THREE QUESTIONS FROM THIS SECTION 16 iv a State the stage of program development in which 2mks N ii The programmer would check whether the KN as required program Testing iii The user guide would be written iii The user guide wouldbe written Program do WF The re remy Qpecifcation would be written i A flowchart would be drawn Program design Program testing definition analysis b State the output of the following flowchart segment 2mks Draw a flowchart to compute the combined resistance R of two 51 2mks c i resistors R 1 and Ra 2 in parallel using the formula R _ 1 R R nm A S v2 Read Ri R R 1 1 R 1 R2 V pan Y or ii 17 WRITE A P
21. Enter member Q and Deposit Depo INPUT Name Share IF shares gt 100 Int x Shares aS terest 0 03 x Shares ENDIF Total savings Deposit shares Interest PRINT Name Total savings Interest b Draw a flowchart for the above pseudo code 8mks INPUT Name Shares Deposit Shares gt 100 000 Interest 0 03 x Shares YES Interest 0 05 x Shares Total savings Deposit Shares Interest PRINT Name Total savings Interest 27 a Study the flowehart below and answer the questions that follow e me Me a dod a EVU a List all the outputs from the flowchart 3mks 24 50 102 any correct 3 b What will be the output if the statement in the decision box is changed to 3mks Only one value 11 will be printed V1 LS ii M lt 100 So i M lt 100 Only one value 11 wi dvl iii M 100 NA values starti gwith 1 to infinity i e 11 22 44 V1 c Modify the flowchart prin he sum of all the outputs 9mks M 2M 2 28 The gross salary of employees of Mutson Chemist is based on the Basic and additional benefits Employees with more than 10 year s experience get an additional pay of 10 of their basic salary Bonuses are given as per employees sales of the month as gt 200 000 15 100 000 200 000 10 Below 100 000 5 Draw a flowchart for the program that will calculate Gross salary and output each employee
22. State the value displayed in G1 Solution 15 2mks SUMIF Cells to be tested evaluated expression that defines which cells will be added actual cells to be added 7 10 17 Study the worksheet below and answer the questions that follow A B C D E F 1 2 SKYWAYS AGENCIES 3 PRODUCT REGION 1 J REGION 2 REGION3 REGION4 TOTAL Sale 4 Rexona 3400 3 700 4000 4100 5 Lifebuoy 2500 2600 2100 2500 6 Qimo 6000 6100 6300 1600 7 Ushindi 1200 1500 1400 6400 8 Carmel 7000 6900 7200 8000 9 Total 10 Maximum 11 Average i ii iii 16 Write functions that can be entered to get total maximum and average of each region 3 mks Total Sum B4 B8 Maximum Max B4 B8 Average Average B4 B8 O Write down the function that returns the number of sales i regions whose value is greater than or equal to 2000 WA 1 mk SUMIF B4 E4 gt 2000 1mk The function sum B4 E4 is entered at F function as it appears in the destinatia ED 2mks sum B7 E7 Q a What is a chart wiz in spreadsheets 1mk A chart wizard 0 step procedure of designing spreadsheet charts b te Q of 2mks i pie chart A pie chart is used to show distribution It shows the n copied to F8 Write down the Proportional size of items that make up a data series to the sum of the items ii A line graph A line graph is
23. United States of America What is the full meaning of the acronym ARPA imk Advanced Research Projects Agency Your manager wishes to be connected to the Internet He already has a powerful personal Computer PC a printer and access to a Telephone line However he understands that he will need a Modem State why a modem is required to connect him to the internet 2mks A modem enables one to connect to the Intemet and access information by transmitting data from one computer to another aeross telephone lines The Internet connects millions of computers and telecommunication devices that have different hardwarejandsoftware configurations For these incompatible devices to be able to communicateya protocols 1mk A protocols a set of rules that govern how tow computers can send and receive data on a network Special communication rule that government sending and receiving of messages by computers on a network b Name the two most common protocols for the Internet and state their functions a i ii a b 3mks Transmission control Protocol TCP It governs how data is transferred from one place to another Internet Protocol IP It is used to provide routing from one network to another i e it enable data to be sent amp received by the different computers on a network Explain the following terms as used in internet amp Website Or a A collection group of related Web pages aN anization o
24. be transmitted over analogue telephone lines 3 State three advantages and three disadvantages of computer networking 6mks Advantages Sharing of resources between the computers Sharing of risks Provides cheaper and efficient communication Running cost is low because of the minimal hardware required Reliable and error free Enhances faster communication It is not time consuming Disadvantages of networking 4 a What is a distributed system High initial installation cost i e expensive to install Security threats e g hacking which posses a great danger to loss of information Moral and cultural effects Spread of terrorism drug trafficking and viruses LS Over reliance on networks My 2mks ma different processors computers which are A This is a system in which data is on the same network but pl ate locations b State any two advant us systems 2mks There is sharin a amp other resources Religies Q computer of the burden of processing data A computer does not affect the operations of the other terminals Processing load is shared equally hence no time wastage There is faster processing of data since each machine can process amp store its data It doesn t need powerful amp expensive servers for data storage It can accommodate users with variety of needs Creation of employment at the remote centers Distinguish between bounded and unbounded transmission media giv
25. conduct a video conference 4mks b A computer A digital video camera camcorder attached to a computer Network software for video conferencing A microphone Speakers Define the term E commerce Qmo E commerce is a way of doing business where the n carried out electronically without the seller and buyer AN lly List down two advantages of e commerce 9 modern business me environment 2mks Reduces traveling hence saves m i A company can access over the world and is not limited by space amp wagons Reduces operati stS of small business as they can establish websites where they can auction the services This also increases their sales 10 ocr Oa has been applied to each of the following areas i Transportation systems 2mks Used by railway corporations to coordinate the movement of their goods amp wagons Used in airline industry for air traffic control surveillance of airspace using radar equipment Used in shipping control 11 vi viii Used in automobile traffic control in busy towns i e to simulate the timing of traffic lights Reservation systems 2mks To keep record of reservation For online reservation i e provide online remote services Paperless transaction Paying via credit cards Easy to check for vacant positions OX Law enforcement W For keeping record on fingerprints Biometric analysis in crime detection ovide immediate
26. contains 40 tracks on each side The tracks are divided into 9 sectors of 512 bytes each What is the total capacity of the disk in megabytes 2mks Total tracks 40 x 2 80 Total sectors 80 x 9 720 Total bytes 720 x 512 368 640 bytes LS lt gt 1 048 576 bytes So If 1 MB 368 640 bytes 368 640 OA 352 29 By giving exampl entiate between primary and Secondary Computer storage 3 mks 30 Primary Memory Secondary Memory 1 Used for holding data amp instructions required immediately by the CPU It is accessed directly by the CPU Provides fast access to information is accurate amp reliable It is expensive per bit of memory dues to the technology involved It has low limited storage capacity It is volatile amp therefore it is used to store temporary programs amp data The speed of the processor dep on the size amp type storage E g Read Only ROM amp Random Qe RAM 1 Used for storing backup information that is not needed immediately by the CPU It is not accessed directly by the CPU Provides slow access of information Secondary PN are cheap it has hi apacity gt o kA olatile i e stores data 9 ntly g punched cards magnetic tapes floppy disks hard disks etc a State four functions of Read Only Memory ROM It stores Firmware bootstrap instructions the essential files the computer uses w
27. easy production of financial reports They are cheaper than manual systems amp Write down all the input and output devices oe of Pesa point in Kenya AS Keyboard The ATM card Screen Visual display QS Printer List down W of ATM cards 3mks fer 2 service to customers Ens ore flexibility in cash deposits and withdrawals It is secure because it requires a personal identification number Pin which is only known by the card holder There is no need for human bank clerks 6 a State four components of an electronic Point of sale terminal 4mks b 7 Define the following terms a b Terminal e g Console which is connected to the main computer Monitor Printer Give two advantages of using electronic point of sale termi opposed to manual entry at a supermarket checkout counter OX 2mks AS It ensures faster entry of data since the aneo Gy not have to enter details Fewer errors made by employees i e correct p at the point of entry manually Ensures good stock manageme Biometric analysis This is the stud ement amp analysis of human biological characteristics It uses a computer_a metric device to recognize amp analyze features of human body parts Sua lips voice iris colour etc Telecommuting A situation where an employee works in a location that is remote from the normal place of work either on full time or part time basis 8 Outline four devices required in order to
28. generation computers NA Used large scale integr ted LSI circuits amp very large scale integrated VLSI circuits 1 ae BN amp very fast Qe memory capacity Nan disks bubble memories amp optical disks were used for storage The first operating system was introduced Fifth generation computers Are the modern computers 10 11 Are designed constructed using parallel architectures 3 D circuit design amp superconducting materials Are very powerful with very high processing speeds The computers can perform multiprocessing Have virtually unlimited very high memory sizes Can support complex programs z Use advanced hard disks and optical disks for storage oy Ds Use of zip disks z Use of multi user operating systems amp kA ication programs State four factors used to classify co Physical size amp processin Power Functionality node Method of operation i of te Ma erences between desktop computers and laptop computers esktop is designed to be used when placed on a desk in an office environment A laptop can be used comfortably when placed on the User s lap s CPU A laptop is small amp portable desktop computers are not portable a Explain the emerging trends in microcomputer technology in relation to size 12 13 14 PCs are becoming small and portable e g personal Digital Assistant PDA b Give two reasons why sma
29. i ii INTRODUCTION TO COMPUTERS a Clearly define a computer A computer is an electronic device that operates works under the control of programs stored in its own memory unit An electronic device that accepts data as input and transforms it under the influence of a set of special instructions called programs to produce the desired output referred to as information O b Give one reason why a computer is referred to AA Ran device It uses electrical signals to process data It is made up of electronic componen s electric energy to operate Explain the following terms Q Pinas science Data A collectio Ou S figures or instructions that do not have much meaning to the user O Program A computer program is a set of related instructions which specify how data is to be processed A set of instructions used to guide a computer through a process iii iv Data processing It is the process of collecting all terms of data together amp converting them into information Information Data which has been refined summarized amp manipulated in the way you want it or into a more meaningful form for decision making amp State any three functions of a computer A Accepting data Processing the data Explain the following input outp rms as used in computer systems Give an example Producing information for each Q a Read nsfer data from an input device to the compute
30. in house developed software for the processing activities rather than use of standard e i What is in house developed software These are programs that are uniquely desi itten by the user or a software house under contract to meet the speci QS to perform a specific job or solve only specific orga tion of a particular user or organization They are usually custo processing tasks in o ii Give two 2 be influencing these organizations for such a decision 2 mks Ne well tested program which he she is able to use with confidence The program provides all the facilities required to solve a particular problem The purchaser has direct control over the package as he she is involved in its Production The user is able to quickly implement the results obtained from the use of the package 55 56 57 58 They can easily be modified to meet specific user s needs without involving expert programmers Differentiate between single purpose programs and integrated software Single purpose software is developed for only one purpose while integrated software is a suite of more than one program and can be used to carry out a variety of tasks Explain the following considerations when purchasing software 2 mks i Authenticity It is the genuineness validity or legitimacy of oftWare ihe copy of the software you buy should be accompanied by the licenge ad c rtificate of authenticity o
31. is a program that is in machine readable form Ao i a source program by use of a translator OX O S 2mks by step processing logic of a program lish like statements that describe the b Flowchart and pseudo code A flowchart is a graphical representati while pseudo code is a set of stru processing steps to be fe lve a given problem What do the follo LG ations stand for 2mks i ery formula Translator ii CO Common business oriented language iii OOP Object Oriented Programming a Define a Language translator 1mk This is a language processor such as an assembler interpreter or compiler that converts the source program into object code 9 10 b Name the stages of a progra Give two advantages of compiling a program rather than interpreting it 2mks Interpreters translate the source program one statement line at a time Compilers translate the entire source code at once before execution Interpreters translate the program each time it runs hence slower than compiling Complied programs can be saved on a storage media It does n ire any further translation any time the program is run hence executes Q interpreted amp programs Interpreter translation takes less memory whi ed programs require more memory as the object code files are lar in their logical sequence 31 2 Problem recognition Problem definiti ae Program AN Q NV and debugging Program imp
32. not affected by water and dust Have a relatively high access speed Cheaper per unit of storage Optical disks can be used for storage of large volumes of data hence making them economical Have high data transfer rates OX lt gt Viewing directories TREE Renaming directories of files N RENAME Deleting a di 2 RD DELTREE Distinguish b pying and moving text 2 mks gt a duplicating copy of text moving is relocating transferring text from one pla a document to another In copying the original text is left intact while in moving all the selected text is transferred from its original location to a new location 14 15 a Name two methods of paper orientation Portrait Landscape b Name two keys used to delete text in a document 1 mk Delete Database creating facility A Table filers structures for holding related O Backspace amp Name two features of a database package As Records database updating facility Search facility that enables the us find information Qh Forms input screens dor viewing and entering data into a table Sorting F i nables the user to organize amp arrange the records within the through the records in the database so as to database ort ting facility Que cility Data validating facility which ensures that the correct data is entered into the database Macros which are used to automate frequently performed procedures or tasks S
33. student record has attributes such as Name admission number class etc State two methods tools that a system analyst may use to design a system 2mks Use of system flowcharts Data flow diagrams Entity relationship models Structured charts Explain three tasks that are carried out during System implementation 3mks File conversions Staff training Project management Changeover Strategies Your school has decided to replace its library control system The current system was implemented ten years ago but has restricted reporting facilities and has a text based interface The school intents to replace the old system with a new computerized system and is now considering both Parallel running and direct changeover a i Briefly explain the terms parallel running and direct changeover as used in system implementation 2mks e Parallel running is where both the old and the new systems are run in parallel to each other a the same time for sometime until users have gained confidence in the new system Data is processed on both systems in order to compare their performance and also cross check the results e Direct changeover is a complete replacement of the old system with the new system in one bold move The old system is stopped amp abandoned and the new system starts operating immediately ii Give two disadvantages of direct changeover byer parallel running 1mk O It may be
34. tested nay It is easier to document specific gt Use of modules can be named i Q y that they are consistent amp easy to find in documentation It is flexible Define lection to program control structures 1mk ctio rs to a situation where further program execution depends on making a decision from two or more alternatives List four selection control structures used in writing a program 4mks IF THEN IF THEN ELSE Nested IF CASE OFF 18 a Name the control structure depicted by the following diagram 2mks Selection control structure e g If then oe b Name the symbols labeled A a diagram above 2mks A Decision box lt B Process symbol 19 Define the term A amp in computer programming 1mk u An array is 20 Draw gt rcr diagram showing 2mks a IF THEN selection Condition Execute statements between THEN amp ENDIF cture that stores several data items of the same type Continuation of program b IF THEN ELSE selection 2mks TRUE FALSE Execute statements between Execute statements betw THEN amp ELSE ELSE amp ENDIF Execute statements after ENDIF Continuation of program c REPEAT UNTIL loop 4mks N Number of loops Count 0 Repeat process Count Count 21 a With aid of a pseudo code and a flowchart design an algorithm that would e Prompt the user to enter two number
35. the task of data processing even faster iii Artificial neural networks 2mks This is the use of electronic devices amp software to emulate the learning process of the human brain and how it recognizes patterns Explain the impact of information technology on organization in each of the following areas i Competition 2 mks Ability to advertise in the internet Improved quality goods amp services Reduced operational costs ii Pace of growth Reduced costs Reduced need for manpower Reduced space requirement Greater output wy a State three reasons why Q y resist the introduction of information and communication Tech i Fear of ey ii ar o their jobs By installing the computer into an organization employees to their place of work le are creatures of habit hence are afraid of change fear hey might end up losing their jobs iii Fear of failure Since the computer is very new in a given working environment the people will be afraid that they might never get used to it iv Loss of control The management fear that once a computer system is implemented they might lose control of the organization CAREER OPPORTUNITIES IN ICT 1 Give a brief description of the following careers available in the computing field i A Software engineers is one who is skilled in software development and technical operations of computer hardware He develops and updates both system and app
36. type of processor etc Basic design of Q uter It is an IBM compatible or apple computer Hardware D ility er Mion to be done i e the applications intended for the computer ndliness or human computer interface i e it is command line based Menu driven or graphical user interface Availability in the Markey e g Microsoft Windows based operating systems are very common vii Portability viii Cost how expensive the OS is ix Reliability i e can it run without crashing stop responding to commands x The method of communicating with the computer e g the number of peripherals xi The method of operating the computer 13 Explain how windows organizes information in reference to files and folders It stores related data amp information records into files and re Gy into folders amp subfolders V O 14 a Distinguish between systems files and appli N 2 mks System files hold critical system infor ile application files hold programs data b State the extensions used signif O llowing file types 2 mks i Driver or system file S ii Batch file BAT 15 a List and e n the three parts of the windows Taskbar 3 mks q Provides access to the start menu Task Manager Displays buttons of currently running tasks Systemtray displays icons of applications that automatically start and run in the background b Outline the procedure of renaming a file or folder using
37. vi Fraud use of computers to conceal information or cheat other people with the intention of gaining money or information vii Trespass illegal physical entry to restricted places where computer hardware software amp backed up data is kept 3 Outline four ways of preventing piracy with regard to data and information 4mks Enact amp enforce copyright laws and other regtlatery frameworks that protect the owners of data amp information against pifacy make software cheap enough to increase affordability use licenses and certifieates of authenticity to identify originals Set installation passwerds that prevent illegal installation of software What is a Computer virus 2mks This is a program intentionally written to destroy data information or the working of other programs inn a computer system b i State two ways through which computer viruses may be controlled 2 mks Running antivirus software programs regularly Controlling the movement of storage media e g floppy disks flash disk etc in and out of the computer room Disabling the floppy disk drives ii Explain how each of the two ways listen in b i above assist in controlling computer viruses 2mks Antivirus software helps to detect and remove the viruses from the computer controlling the movement of floppy disks ensures that infected disks are not inserted into computers 5 Computer systems need maximum security to prevent an unauthofrizedyaccess S
38. while a flat panel displays a limited number ofc S CRT consumes more electrical power than flat panel displays The screen of a flat panel is much thinner amp smaller than that of a CRT The screen resolution of a CRT is adjustable while that of a flat panel is often set c 36 37 Give there examples of flat panel monitors available in the market today Liquid crystal displays LCD Electro luminescent EL Gas plasma Thin Film Transistor TFT a What are pixels Pixels picture elements are dots on the screen that X ar and images b What role do pixels play in screen display w They determine the clarity of images o en c Give two advantages of th ts of pixels per square centimeter 2 mks Higher screen resoluti z Displays of 4 images The screen display a higher number of different images a ne Oa printers 1 mk Are usually low speed printers that print one character at a time b Give two examples of character printers Dot matrix Thermal 38 39 Daisy wheel Inkjet Golf ball Distinguish between impact and non impact printers and give two examples of each Impact printers print by striking mechanism amp are noisy e g Dot matrix Daisy wheel and Golf Ball drum and chain printer Non impact printers print either by laser ink or the Ar mechanism amp are silent e g Laser Inkjet thermal printer NN ographic a Distinguis
39. will be possible for people in various business organizations to work from home Such working using a PC as a remote terminal is often described as teleworking State three advantages and three disadvantages of working from home 12 mks Advantages Reduces unnecessary travel tothe place of work Reduces traveling exp nse 1 saves traveling time risk and cost There is less stre sdue t commuting inconveniences such as traffic jams Reduces office space equipment and cost Extends working hours Suitable for people with disabilities because they are able to overcome the barrier of not being able to commute to an office People can live where they choose without the worry of having to move towns and break up social amp family networks in order to find suitable employment 18 Disadvantages Lack unavailability of appropriate facilities to allow the work to be done There is poor security on home offices Privacy threats Lack of control and supervision The workers have to be able to motive themselves to work without supervision amp There is possible delegation of duties to unauthorized p A Isolated employees may be exploited in an Na they can t easily get support from co workers a Explain three ways by which com O can protect their eyes from harmful emissions from the computer streg 6 mks Using antiglare radiation filte screens that are specially tinted to reduce the
40. work under windows environment 3 mks 18 c List three Multimedia components Optical drive CD ROM or DVD ROM drive Speakers headphones Media Player software Microphone Sound card adapter TV Tuner card Editing card Digital camera VGA or SVGA graphics card and moni A RAM of 32 MB or higher d i What is meant by com i anufacture CAM is the use of computers the manufacture of industrial products ii Give t O Arc es of computer aided design software P Draffics 3 Dmacs a Give three examples of network software UNIX 2 mks 2 mks 3 mks Linux Novell NetWare Microsoft Windows NT Microsoft Windows 2000 Microsoft Windows 2003 b List any three items that may be referred to as data terminal e Gy in a network i 3 mks Servers My Dummy terminals oe File servers Terminators q c Briefly i wing terms as used in networking 4 mks i Re Qion This e transfer of data between computers in different locations Itis along distance data transfer without the use of cables Printers Modems ii Distributed processing Distributed processing is the sharing of computer processing power d State three advantages and two disadvantages of mesh network topology 5 mks Advantages of mesh topology It is fast Failure on one mode will not cause communication breakdown Easy to troublesh
41. 20 Gigabytes f Some of esa s in the school use the computer to do homework Name the This is the measure of t cka to Do ations and draw graphs 1 mk Spreadsheets Write an essay Word processor 20 iii Make a poster Art d Students enjoy playing noisy computer games i Which two hardware items are needed to produce sound 2 mks Sound card Speakers ii Which input device is only used for playing games Joystick 1 mk AS ntains the files CATS EXAMS A school organizes its work in directories The direc and ASSIGNMENTS The directory of SP co spreadsheet files The directory DB contains the database files The director contained in the OTHERS directory The directory WP also contains the directory Given that the directory STUDENT contains directories SP DB and OTHERS a Draw the dire 4 structure with C as the root 7 mks b Write the path at which the contents of subdirectory DB can be erased or displayed 2 mks C STUDENT DB gt c Write the path for the directory PROG ey mks d Give two reasons for storing files in anni C STUDENT OTHERS PROG gt directories 2 mks Management of the files will be easier Retrieving of certain files will be To avoid accidental del of files when the files in C are being deleted e Give two di Ws f using command driven interfaces as compared to menu driven int 2 mks e Q know the command to type
42. ECTION B 60 MARKS Answer question 16 and any other three questions from this section 16 Study the flowchart below and answer the questions that follow a Write a high level langu 7 mks ge program for the above flowchart Oe a Program Uses Win Q A OUNT INTEGER BEGIN A 0 B 1 REPEAT Writeln B COUNT COUNT 1 C A B A B B C UNTIL COUNT 10 END OY ARo OR X Program ABC input output ee ae Ne FOR COUNT 0 TO 10 DO USES Win CRT VAR Begin Writeln B C A B A B END b List the outputs of the flowchart above 5 mks 1 1 2 3 5 8 13 21 34 55 any ten integers LS lt c Modify the flowcharts so that it adds up all its ak displays the sum obtained Pa 3 mks 17 A computer specification has the following details Pentium II 1 44 MB floppy disk drive 20 GB hard disk Full multimedia 17 SVGA monitor Pre installed operating system Pre installed office suite a What is meant by i 1 44 MB floppy disk drive Kli 1 44 megabytes It has a floppy disk for ii 20 GB hard disk Refers to t capacity of the hard disk in Gigabytes iii Prono Refers to the type colour and size 17 inch of the screen b Which operating system might be pre installed in this computer and why 2 mks Any version of windows Linux Macintosh OS 2 UNIX Solaris Scounix Reason the office suite can only
43. It is ser friendly i e it is not easy to use The user is required to master the format syntax of all commands and their usage perfectly Writing commands is time consuming K C S E SAMPLE PAPER Kenya Certificate of Secondary Education Plus Agencies 451 1 computer studies Paper 1 theory 2 1 2 hours INSTRUCTIONS TO CANDIDATES This paper consists of TWO sections A and B Answer ALL the questions in section A RS Answer questions 16 and any other THREE questions from a FOR OFFICIAL USE ONLY SECTION Vi 20 TOTAL SCORE SECTION A 40 Marks Answer all the questions in this section 1 a What is disk formatting Process of preparing a new disk for use by imprinting empty tracks amp sectors on the surface of the disk that can be recognized and access by a particular operating system The preparation initialization of a disk for storage of data b Indicate whether the following devices are used for input or tout A O i Plotter Output aN ii Light pen Input iii mouse Input iv Visual display unit Input qO a Explain why the following controls should be implemented for computer based systems g 2 mks i Back ups a be used to recover restore prevent lost data ii gt ords control access to computer systems facilities b For each of the following give one reason why they are not allowed in a computer laboratory 2 mks
44. ROGRAM USING Pascal or c languages for the flowchart in c i above a Smks PROGRAM resistors Input Output VAR R R1 R2 Real V1 Begin My Writeln Input R1 and R2 Readln R1 zO R 1 1 R 1 R2 3 ax m reci Imk result r 1mk Writeln R y gt a List par a activities in word processing 3mks cra case Borders Background Drop caps Bullets and numbering alignment Paragraph Spacing Indentation Tabs columns c b Differentiate between bolding and highlighting text 2mks Highlighting Selecting or marking a given of text e g a word sentence or paragraph in order to work with it Highlighting is temporary Bolding se To add emphasis to the text by thickening ay aracters making the selected text appear darker then the rest Bolding is permanents The following information sh i and expenditure for behayote matatu for five days The i ri onday to Friday was Ksh 4 000 9 000 10 000 15 000 e 4 and 12 000 N ile the expenditure for the same period was Kshs 2 000 e 000 7 000 Q Aoo respectively i Draw a spreadsheet that would contain the information Indicate the rows as 1 2 3 And the columns as a B C 4mks A B C 1 BEBA YOTE MATATU 2 Day Income Expenditure LS O Ksh Ksh eS 3 Monday 4 000 AS 4 Tuesday 9 000 Wednesday Thursday
45. X and Y e Divide X by Y However if the value of Y is 0 the program should display an error message Error Division by zero START PRINT Enter two numbers X and Y Input X Y SY IF Y 0 THEN A PRINT Error division by zero ELSE Quotient X Y PRINT X Y Q ENDIF STOP aQ Flowchart YES Error Division by 0 b Write down the assignment statement used in the algorithm above 2mks Quotient x Y c Which program control structure is depicted in the algorithm 1mk If then Else 22 Draw a flowchart for a program that is to prompt for N numbers ulate the sum and them find the average The output is the accumulated t Ai average SN Initialize Sum 0 Count 0 Sum Sum N Count Count 1 Average Sum Count lt u YES PRINT Sum Average 23 Write a pseudo code that reads temperature for each day in a week in degree Celsius converts the celcius into Fahrenheit and then calculate the average weekly temperatures The program should output the calculated average in degrees Fahrenheit START INPUT temperature in C SET Initial day to 0 WHILE Initial day lt 6 DO F 32 9c 5 INPUT temperature in C Initial day Initial day Cumulative 1 F END WHIL Average mmulative 7 PRINT av fp 24 Michael deposits 1 000 in a bank at an interest rat of 10 per year At the end of each year the interest earn
46. ages 2 Processor Memory RAM ge Secondary storage devices Input output devic Communic Q T O amp ation ports c There are several types of operating systems in use today State two examples of Operating systems which you are familiar 2 mks Disk Operating System DOS Windows MacOS Unix Linux Name the two latest operating systems from Microsoft corporation 2 mks Windows XP 7 Windows Vista Explain any four functions of an operating system software 8 mks i Memory allocation amp loading of programs LS 5 Loads application programs from an external eS e available locations in the Main memory RAM It keeps track monitors of the parts o ory that are in use and those which are free ii Processor managemen a The processor can o Q one program at any one time Therefore in a multi tasking system e CPU must be carefully control amp monitored The OS must decide A will be allowed into the system and for how long iii b sc ng it schedules amp loads programs in order to provide a continuous Ve processing This is necessary when more than one application program is occupying the main storage iv Error reporting and interrupt handling The OS reports any errors that occur during program execution v Management of CPU time vi vii viii ix x In a multi taking system where several user programs share the computer reso
47. amples of word processing software widely used in the market today V mks Microsoft word amp WordPerfect A Lotus WordPerfect WordStar WordPad O e ion method of typing a document on a Typewriter against usin d processor 6mks s es using a word processor is easy it is hard to correct mistakes ultiple copies of the same page is possible using a word processor but it is not possible to produce multiple copies on a typewriter Text formatting features are available on a word processor e g front size font type font colour boldfacing italicization etc The documents created can be stored in the computer for future reference a b Typing using a word processor is easier amp more efficient because most of the actions are automatic For example the word wrap feature automatically takes the text cursor to the beginning of the next line once it reaches the end of the current line A new page is automatically inserted after reaching the end of the current page Graphics can be added within documents using a word processor Grammar amp spelling mistakes can be checked amp a text editing tool that provides alternative words with similar meanings letters and sent them to several people A Q What is a template amp 1mk It is a document that acts as a bl fi outline for other documents of the same type It contains the QS this type State two Z using a template to create a document
48. as you may accidentally knock the peripheral devices ly Q people should enter the computer room Co rs users should be trained on how to use computers frequently Computer illiterates should not be allowed to operate the computers collect any waste papers which might be lying in the computer room amp put them into the dustbin Shut the door of the computer room properly 22 23 24 25 26 Describe the ideal environment for a computer to work properly 3 mks Should be free from dust water and magnets Should be kept in well ventilated rooms with optimum medium humidity Explain why smoke and Dust particles are harmful to a computer Dust and smoke particles settle on storage devices and may scratch them during read write operation It affects the cooling of the computer Identify three facilities that will ensure proper ventilation in a room Large amp enough windows and doors Installing fans Installing air conditioning system Avoid overcrowding of either machines or people in the room Why must foods and beverages be kept out of the computer room Food particles may fall into the moving parts of the computer and damage them Liquids may spill into the computer parts causing rusting or electrical faults Why would it not be good to install Powder or Water based fire extinguishers in the computer room Powder particles settle on storage devices and may scratch them during read wr
49. at Do not expose it to dust smoke particles Do not unprocedurally switch off the computer c Describe the structure of a hard disk in reference to ovina Gog cks and sectors The surface of hard disk is divided into circles Pe tracks on several platters are called cylinders The tracks are further subdivided into lt O ae can be grouped to form clusters State two reasons why Magnetic tape ommonly used as computer data storage medium today Are slow when retrieving da his is because of the linear storage of data o the tape Do not fully us ording surface due to inter record Gaps Differe i Mic puter and microprocessor A microcomputer is a computer whose Central Processing Unit CPU has been implemented with a microprocessor A microprocessor is a small computer processor mainly a combination of the ALU amp CU manufactured on a single chip ii iii iv v vi vii Volatile memory and non volatile memory Volatile memory is temporary while non volatile memory is permanent RAM and ROM RAM is a temporary and rewritable memory while ROM is a permanent and read only memory Hard disk and floppy disk o Hard disk is a hard metallic platter used to store dat Mores in a metallic housing casing Re Hard disk is metallic Shinny and non O Magnetic and optical storag e In magnetic storage me WY using magnesium while in optical storage media data is record
50. can edit save sort filter use forms to enter and view records and worksheet data Scientific applications spreadsheets can be used by scientists amp researchers to compile and analyze their results Statistical analysis spreadsheets provide a set of statistical Functions tools that can be used to develop complex statistical or engineering analyses e g teachers can compile their students marks and produce results v Forecasting using the what if analysis technique spreadsheets can be used to find out the effect of changing certain values in a worksheet on the other cells This helps in financial forecasting budgeting etc 5 State five features of spreadsheets that are useful in financial modeling 5mks e Have inbuilt functions amp formulae which can be used to perform most mathematical statistical trigonometric or financial calculations e Allows automatic recalculation on formulae LS AQ d to find out the effect of e have ability to perform what if analysis whi changing certain values in a worksheet on ny s e Have the ability to sort amp filter data e Have a data validation facility res that the correct data is entered into the spreadsheet e Have a chart facility that can d used to draw Line graphs Bar charts Pie charts Histogram lt Q e Somes gt have a SOLVER facility that is used to uncover the best uses of Ww es so that desired goals such as profit can be maximi
51. cial kind Q ound at the back of a computer used to connect an external such peripheral ns inside the computer Data interface cable as a printer monitor mouse scanner modem flash disk etc to These are special cables that connect all the peripheral devices to the motherboard and the CPU They transmit data signals and information to and from the devices c 46 47 48 Power cable Cable for power supply to devices State the function of the power supply unit found in the system unit 1 mk It supplies stable power to the motherboard and other internal devices of a computer Converts the potentially dangerous alternating current AC a low voltage a Name any two peripheral devices which get gt supply through ports Keyboard b State the type of port lt j would commonly be used to connect the following devices direct current DC usable by the computer Mouse i Mouse CA 2 Serial or USB ii Modem D Serial iii E a Parallel a Explain two differences between serial and parallel communication ports of a computer Serial ports have 9 pins while parallel ports have holes for 9 or 25 pins Parallel cables transmit several bits of data simultaneously while serial cables transmit One bit at a time 49 50 Serial cables are slower than parallel cable Serial cables allow for 2 ways communication i e communication to and from the computer and the device co
52. computer pro he anguage must be understood by the computer for it to execute Explain the meaning ote as used in computer programming 2mks rd 1 Syntax th s that govern the arrangement of commands in a p cul Magee ii XY the meaning attached to every command in a particular language a What are low level languages Give their features 4mks These are the basic programming languages which can easily be understood by the computer directly or which require little effort to be translated into computer understandable form Features b They are machine hardware oriented They are not portable i e a program written for one computer cannot be installed and used on another computer of a different family They use Mnemonic codes They frequently used symbolic addresses O Give three advantages of high level languages as op w level languages A 3mks Easier to learn understand and use Easily portable i e they can be transf run with little or no modificatio t The programs are short een computers of different families and er time to be translated More flexible henc enhance the creativity of the programmer and increase his her They are user friendly amp problem oriented hence can be used to solve problems arising from the real world Examine two features of fourth generation languages 4GLS 2mks Have programming tools such as command buttons forms textboxes e
53. d 0 9 Cursor control keys PgUp PgDn Home end Arrow keys Special PC keys Ctrl Shift Alt Ins Enter Spacebar Caps lock Num lock etc Editing keys Del Backspace and spacebar c Name the keyboard keys that will help you LS 2 mks ey i Type the upper character in a key ii Execute a selected command S QS ae V ey COMPUTER SYSTEMS Define the following terms as used in computing i System A collection of independent entities that collectively work together to achieve a desired goal ii Computer system A collection of entities that work together to process ens information using computers RO working together in data tput from a computer A collection of hardware software and li inputting processing and production of r Differentiate between a computer and a A computer is made up A ware and software while a computer system integrates hardware softw nd user system a List and explai ctional elements of a computer system 6 mks Haraware Th he physical amp tangible devices that make up a computer systems e g system unit input devices output devices and storage devices Software These are programs amp data used in a computer system that enable it perform a number of specific functions e g operating systems application programs utility programs programming languages amp device drives Live ware people ware Thes
54. e ICT Information and Communication Technology e ICT refers to the integration of computers and telecommunication facilities for the purpose of communication State four areas where computers are used today 4mks 1 Financial systems e g accounting stock exchange payroll Banking etc il Transport systems e g air traffic control shippingscontrof automobile traffic control iii Entertainment systems e g used in showing Movies playing music amp computer games iv Scientific research i e weathemforecasting medical research military amp space exploration State two ways in which afcomputer may be used in efficient running of a hospital Keeping records of in oming and outgoing patients In elects62eardiogram screening and monitoring analyzing the sickness amp checking for damages e g X ray Acomputer controls life supporting machines For inventory control To access foreign expertise or labour i e to get in touch with consultants or surgeons in another country thereby reducing traveling of patients amp professionals a Name the type of processing that would be required by a payroll system 1mk Batch processing b a b Identify two benefits of using computers in accounting systems 2mks They make the processing of financial records easier Error checking procedures can e established to ensure accuracy amp security of data Used to store volumes of financial records Ensure fast amp
55. e are the people who coordinate the various activities which are necessary to make a computer system perform useful tasks e g data entry clerks computer operators programmers system analysis etc b Draw a well labeled diagram showing the functional units of computer hardware mS Central Processing Unit CPU Arithmetic amp Logic Unit Control Unit Output devices Input devices Secondary storage 4 a Give two main functions of a computer input device 2 marks Accepts data amp instructions from the user and sends them into the CPU V Converts data into a form that the computer can understand i e machine Sensible readable form b Give an example of a 3 marks i Device that reads data scanning device Scanner Digital cameras Barcode readers Credit smart card readers Kimball tag readers OMR OCR MICR etc ii Keying device QS Keyboard Keypad ot OH Pointing dev roy Light pen Joystick h Voice input device Microphone v Printing device Printer Plotter 5 State two advantages of using a mouse instead of a keyboard 2 marks The mouse is easy amp convenient to use Modern software includes an option to use it It selects a position on screen much more quickly than a keyboard 6 Outline any two advantages of a light pen as an input device 2 m It is a faster input device because it involves ju
56. e following concepts as used in the windows environment Desktop Desktop is mostly an empty screen that appears when windows starts and has some standard icons that show that the computer is ready for use b 10 Window c d e f A rectangular area on a computer screen in which text graphical images or the contents of a folder or disk may be displaced Icon A little picture on the computer screen representing a program disk file folder or any other item Sidekick menu A submenu that appears either on the right or left of a we Taskbar S A long bar strip that runs across the d displays the start button and any other Task Any x L e in windows and is displayed on the taskbar e g running active tasks program 3 mks my functions of taskbar Indicates what programs are running Holds minimized programs Provides a shortcut menu for arranging programs 11 12 i ii iii iv v vi State two differences between Disk Operating System DOS and Windows operating system 2 mks DOS Windows i Single tasking i Multi tasking ii Single user ii Multi user ii Command driven interface iii Graphical User Interface iv Not easy to use iv User friendly SS Identify three factors you would consider on an operating system for use in a computer 3 mks Qe e g RAM memory size Hard disk capacity Hardware configuratio
57. e limited to Yes No e Where 100 coverage is not essential e Where privacy anonymity of the respondents is to be maintained b Outline three advantages of questionnaires 3mks e Use of questionnaires gives the respondents privacy hence there is likelihood that the information given is sincere and real e Questions can be answered quickly since respondents can complete and return the questionnaires at their convenient time e tis a cheap method of collecting data from large number of individuals e Responses can easily be tabulated and analyzed quickly 14 a Explain the importance of using automated methods in fact finding 1mk Automated method of data collection can be used in asa are not easily accessible b Give one example of automated information Use of a video camera to capture mo Use of Tape recorder 15 Mention the four factors that may be sir in order to design a good file 4mks A o Output specifica tput from the system pecifications o H a O Q specifications 16 State four factors that may be considered in order to design a good file 4mks o Input specifications o AO e specifications Record key fields Data type for each field Length of each field Backup and recovery strategies 17 18 19 20 Define the term attribute 1mk An attribute is a unique characteristic of a record for which a data value can be stored in the system database E g a
58. ed is added to the amount on deposit and this becomes the new deposit for the next year Develop a pseudo code to determine the year in which the amount accumulated first exceeds 2 000 Also for each year print the year starting from 1 the deposit the Interest earned and the total accumulated at the end of the year START LS DF Input initial deposit Interest rate and Target EAN Set Deposit to 1000 Set Year to 0 REAPEAT Ves Yeti Qs x Interest Dep sit Total Q nterest De al S sit gt 2000 PR eposit Year STOP 25 Study the flowchart diagram below and answer the questions that follow R R 1 Term R 2 Sum Sum Term stop gt a What will be the value of the QA Show how you arrive at your answer f 5mks 0 0x2 0 0 0 1 Ny Bre 0 2 2 2 2x2 8 2 8 10 Sum 3 3x2 24 10 24 34 The value of Sum 34 26 a Mwalimu savings society MSS Pays 5 interest on shares exceeding 100 000 shillings and 3 on shares that do not meet this target However no interest is paid on deposits in the member s MSS bank account Design a pseudo code for a program that would 1 Prompt the user for shares and deposit of particular members amp ii Calculate the interest and total savings OX iii Display the interest and total savings on the lar members of the society 7mks START STOP PRINT
59. ediusing a beam of light laser Hardcopy opy output ie M prin copy e g printout on paper such as letters while softcopy is inta e information e g screen display or music MICR and OCR scanners MICR uses magnetic technology to read magnetic characters while OCR uses laser light technology to read characters 27 28 Explain four rules for handling magnetic disks Keep magnetic away from excessive heat This is because heat energy weakens the ability of the magnetic media to store data Store the media in their cases when not in use in order to protect safeguard their recording surfaces against environmental influences such as dust touch direct sunlight radiations etc Do not drop the disk on the ground Never bring them near moving or strong magneti QA Such bodies might demagnetize the recording surfaces Ba in terms of magnetism impossible When mounting the media into its re ting unit avoid brushing the recording surfaces against the mechanical c s of the drive qw media and off after removing the media from the This is beca nO uation in power might cause demagnetization Put on the power befor drive a Calculate Qis in MB of a two sided floppy disk with 6 sectors per surface and 512 by er sectors No of sectors 2 sides x 6 sectors 12 sectors If 1 sector 512 bytes 12 x 512 6 144 bytes 1 000 000 bytes 1 MB 6 144 1 000 000 0 006144 MB b A double sided disk
60. en relatiye an D7 Absolute column reference only the column reference is absolute A formula to add the contents of B5 and C4 was entered in Cell F5 what will it become when it is copied to Cell H8 1 mk D8 E7 Explain the reason for your answer Gjo When we move to cell H8 from F5 the column changes e the row changes by 3 The formula B5 C4 is als wise This is because of relative referencing Ss G20 Imk What is the equivalent R1C1 r R20C7 AN solute cell reference as used in Ms excel 2mks Relative ce Q means the referencing means that the references of cell used in orm relative to the location of the cell where the formula is placed e g E3 C3 this tells Excel to multiply the contents of C3 by D3 which have been defined in relation to E3 Absolute cell addressing means reference is made to one or more cells in a way which doesn t vary change according to circumstances 13 The fist column in the table below contains formulas as entered into cell D46 In the second column enter the formulas as they would appear when copied to cell B56 4mks Formula in D46 Formula when copied to B56 D1 B11 F5 C10 D15 A20 z H 46 J40 F 46 H50 A C2 E12 D 14 F 2 A 14 A worksheet contains the data shown b Cell AI A2 lt C2 C3 Entry 5 7 1 10 15 15 SUMIF Q C1 C3 lt gt 10 AI A3
61. equirements specification System design System construction coding System implementation System review and a NB Order must be followed 2 as used in system development 2mks This is a ial Study carried out to establish the costs and benefits of a proposed 10 Define the term Fea Ne 11 Youarere ed to develop a registration system for a particular school State two ways in which you would gather the information required for the system development 2mks Study of available documents Observation Interviews Use of questionnaires workshops and seminars Use of automated methods 12 Identify two disadvantages of Observation method used in fact finding 2mks The person being observed may perform differently or change his her behaviour leading to wrong requirements being observed The work being observed may not involve the level of difficultor volume normally experience during that period of time The need to be on the site where the activities ar taking place consumes a lot of time Some activities may take place at odd mes Causing a scheduling inconvenience for the analyst 13 a Name three circumstances4n which it is better to use a Questionnaire than an Interview for gathering information 3mks e If the information tobe gathered is located over widely spread geographical area e Ifa large number of people are to be questioned and the questions to be asked requite short answers or ar
62. essage normally takes Oy minutes depending on the distance to the receiver Efficient A message prepared only once can b ral people Convenient with e mail one can send his es when it is convenient for him her amp the recipient ond at their convenient times g mail users accept less well formatted e overlooked unlike in business letters which are Cheaper in preparing the messa messages and slight typ Q r expected to be error free an matted according to certain standards Disadvantages xX init allation cost is higher Mes may be lost before they can be read due to virus infection Messages may not be kept for future reference due to the high cost of storage 2mks a What is a search engine 2mks Google com Yahoo Com Hotmail com Excite com Briefly describe four factors contributing to Internet access and Aon Kenya ii iii iv 6 Cost for effective use of internet a powerful A puter is needed The cost of installing internet ni one bills is also high hence discouraging internet growth Illiteracy Many people are comp ter literate and therefore have no idea of computer internet se Inadequate infrastruc of infrastructures such as telephone services in gura o hinders growth of internet access Lack of electricity discourage from installing internets in their offices qS of the existence of such services by the public DATA SECURITY amp CONTROL
63. explain the term computer booting Booting tefers to the starting up of a computer It is the entire process that makes the computer ready for use b Explain what happens in the computer during the booting process When the power is switched on internally it first checks whether all the components are in good working condition i e the RAM CMOS BIOS hard disk amp floppy disk drive controllers and the keyboard If no problem is found it then loads the operating systems 37 c i ii d Give and explain two types of booting Cold booting It happens when a computer which was originally off is switched on by pressing the power button on the systems unit The Computer starts by checking all its components to determine whether they are S gt Warm Booting NA This happens when a computer that was origi forced to restart by pressing the functioning properly restart button on the system unit by p Q tore the boot up program the first program to combination of keys on the keyboard CTRL ALT DEL What type of memory be executed on switching onfa co ter Read only X2 1 mk a Whatis a Q keyboard Ani device that lets the user enter commands into the computer for execution by typing b List four types of keys found on a computer keyboard giving an example of each 4 mks Function command keys F1 F12 Alphanumeric Keys A Z 0 9 Numeric keypa
64. f the developer ii Portability It refers to whether a program canbe copied or installed in more than one computer Differentiate between portability with reference to hardware and software In hardware the computer device should be sufficiently small amp light to carry Ta software portability refers to whether a program can be copied from one computer to another or installed in more than one computer a Explain why documentation is necessary for any software package It contains details on how to install use and maintain the software It also shows the purchaser how the program can be used to solve particular problem as well as provide the user with assistance on using the program b A firm intends to purchase new software List three items of documentation that should accompany the software A license Installation guide User manual guide Reference manual A ae or WS i lt 9 ae S OPERATING SYSTEMS The central processor and peripheral devices of a computer system are coordinated by the operating system a Define the term operating system A set of computer programs that normally reside in the main memory and used to control the basic computer hardware resources amp the operation the entire system The main program that controls the execution of user AS d enables the user to access the hardware amp software resources of wO b List two resources components that an o stem man
65. ge amp of purchasing the required equipment A 11 Differentiate between source program and ogram e Source program is the program y the programmer using an editor program either in high level or a 5 Ad e Object program is the pro in machine code or binary form produced by a compiler or V4 er translating the source program and can be readily and can be readily RSS 12 a In ww are the following commands used for i RD Remove directory means deleting a directory from the tree o the computer ii DEL deletes all files in a particular directory b What happens when the following commands are typed in the DOS environment i CD Changes the directory one level up the directory tree 13 a b ii Dir It lists all the contents of the current directory A student presented a budget in the form of a worksheet as follows A B C 1 Item Amount 2 Fare 200 3 Stationery 50 4 Bread 300 5 Miscellaneous 150 6 Total id term Given that the value 0 5 is typed in q0 e the shortest formula that would be typed in cell C2 and then copied Q n to obtain half the values in column B 1 mks B2 B9 gt g Write iM formulae that can be typed to obtain the total in cell B6 and then The student intends to have spent half the a copied to cell C6 SUM B2 B5 2 mks OR B2 B3 B4 B5 14 15 State three operations that can be perfo
66. h between a line printer and nter A page printer prints document line by line 3 b State three ady W s ne disadvantages of page while a line printer prints documents i Laser Printers Advantages Cheap running cost NY Produces high quality of printouts Has a very high speed of printing it is fast 7 Economical in maintenance It is very silent Disadvantages Expensive to purchase amp maintain 40 Involves expensive multiply colour printing ii Inkjet Printers Advantages Cheap to purchase Cheaper multiple colour printing Produces high quality prints Disadvantage Expensive to run i e to buy cartridges LS O Produces a water based print wh a Highlight four factors one should consider gt a printer 4 mks items like printing pape artridges Cost involved i e the printer s io cost of maintenance amp cost of consumable Volume of printing expecte eed of the printer Quality of printi Capability W printer i e multiple copy production paper size etc Ma with other computers in which the printer will operate Ease of maintenance ity to print graphics amp colour Reliability of the printer Application it is required for i e purpose use of the printer Type of paper used by the printer Documentation 41 42 43 Give two advantages of using sound output devices Availability List three advantages of a plotter over normal
67. he feasibility of potential computer applications Reviews the existing system amp makes recommendations on how to improve or implement an alternative system Works hand in hand with programmers to construct a computerized system Coordinates the training of new system users and owners He is the overall project manager of the information system being implemented Some of his duties include assuring quality keeping within schedule amp budgeting 6 Define the following terms LS O i ii iii System control A system control is a method by whi o adapts to changes in the environment in order to give t ected output or perform at the expected level a System bounda ional data analyze it and generate reports that can be used to support the ecision making process in an organization Te State one disadvantage of the Traditional approach in system development 1mk The structure of the old system is not changed in anyway hence hence the weaknesses of the old system are not corrected and are carried forward to the new system 8 What is Prototyping as used in system development 2mks It is a Rapid system program development technique V1 where system developers quickly capture user requirements by designing system interfaces in the presence of the user y 9 Outline the seven steps followed in structured system development 3 2 mks Problem recognition and definition Information gathering R
68. hile booting starting up b Give three characteristics of ROM It stores the system data amp instructions that are necessary for the normal functioning of the computer hardware e g the Kernel supervisor of the OS It stores translation programs code converters used for converting a user s program into machine language It stores special functions facilities peculiar to a given machine It stores character generators for printers amp Video displays It stores instructions used in special purpose Sain fuel pumps x It can only be read but cannot be written to can only read the information in the ROM but cannot write on it unless cial type of ROM Provides permanent or semi pe orage of instructions amp data from the manufacturer NA It is non volatile memory Forms a small of the main storage i e it contributes 30 of the internal Memory D 4 Q files for starting the computer Bootstrap programs c Name two different types of ROM Masked ROM Programmable Read Only Memory PROM Erasable Programmable Read Only Memory EPROM Electrically Alterable Read Only Memory EAROM 31 a Outline three characteristics of Random Access Memory RAM Stores data amp programs temporarily during the times when they are needed in the Main Memory or during execution Provides read amp write facilities i e it allows instructions to be written read o
69. ied List any thee sources of graphics that can be used in Micros 3mks a b From Microsoft clip gallery A From Scanner O By drawing using the Drawing tools a in Ms World Import from another file Explain the concept of k Ss can be used in Microsoft word 3mks Getting rea Q cts and text from other applications into the word processor at Y Terence between object linking and embedding 2mks In li the object imported can only be edited in the original application from which it was created In embedding the object imported becomes part of the current application and can be edited there 19 20 21 22 Give a reason why it may be necessary to merge cells in a table 1mk a b a a To create larger cells in a table without increasing the height or width of the existing cells Define mail merging 2mks The process of generating personalized letters or documents by combining a standard document but addressed to different recipients amp Give two advantages of mail merge over copy and Ke erat times to l e mass mail a document A combining of letters saves time when printin 2mks It allows producing of many documen The mailing list can be re used 40 document Give two advantages o a document before printing 2mks To check t e layout is OK To confir details are outside the printable area o S the document before printing To save on printing pape
70. ing two examples in each e In bounded media data signals are transmitted from the source to the destination through a restricted pathway e g two open wire cables twisted pair cables Coaxial cables fiber optic cables e Unbounded media transmits data without physical connections e wave Satellite oS State what is meant by each of the following data WN edia and give two advantages and three disadvantages for each i Twisted pair cables amp 3mks A twisted pair cable is made up ey ed copper wires twisted around each other RY aei fields from developing around the radio infrared communication in a spiral pattern This two wires as they trangmit data Advantage Q Has high sfer rates of up to 100 Mbps LS O of mass production for telephone use Disadvantage o They suffer from high attenuation o affected by electromagnetic fields o It has low data transmission rates as compared to other cables ii Coaxial cables Coaxial cables consist of two conductors which are insulated and shielded to provide high noise immunity amp also more resistant to electromagnetic interference Advantages o They have a large bandwidth up to 1 Gbps compared to twisted pair cables o They can carry voice data and video signals simultane oy erence than twisted o They are more resistant to radio and electromagnetic i pair cables A Disadvantages o They are hard to work with o They are expensive to 4S
71. ion a wi Pens with reference to the purchase of computers A warranty is an agreement between the buyer and the seller that spells out terms and conditions of after selling a product in case of failure or malfunction A warranty is usually the duration in which your computer is supposed to work without any problem 53 b Why is it important to carefully study a warranty before committing yourself by signing it In order to negotiate on sensitive items like duration after sales services etc c List down three issues to understand about warrants Duration scope of cover How comprehensive is the warranty good warranty should Gay parts of the Liability agreement e g how long should the KAN to repair a fault or replace the product and if he she delays who bears Computer Does the warranty offer online suppo Regularity of service or minera Y What are clones with refer Qs and what is their disadvantage Clones are iO ed computers Disadv wee Gover are not optimized to work with each other They are not as reliable as their brand names like IBM Compaq Hewlett Packard HP Dell Gateway etc 54 a What is standard software These are programs developed packaged and then made available for purchase either directly from the developer though a vendor or a distributor They may be used for a wide variety of purposes b Small and large scale organizers are turning to the use of
72. ional errors committed during data processing 8mks Misreading errors they occur when the user reads source document incorrectly thus entering wrong values e g a user may confuse 5 in the numbem586 with S and type S86 instead Transposition errors they result from incorrecthasrangemient of characters 1 e putting characters in the wrong order especially when Keying data onto a diskette e g the user may enter 396 instead of 369 computational ergors Overflow errors An overflow oceurs if the result from a calculation is too large to fit in the allocated memory space e g if the allocated memory space is able to store an 8 bit character thean overflow will occur if the result of the calculation gives a 9 bit number Define the term data integrity 2mks Data integrity refers to the dependability timeliness availability relevance accuracy amp completeness of data information State three ways of minimizing threats to data integrity 3mks Backing up the data on external storage media Enforcing security measures to control access to data Using error detection amp correction software when transmitting data c a Give three advantages an Advantages CA e Designing user interfaces that minimize chances of invalid data being entered briefly explain real time processing 2mks e Airline reservation systems e Theatre cinema booking e Hotel reservations e Banking systems e Police enquiry sys
73. ionship between different data items forming a ne s Define the ter i 2mks Sorting inv ranging of records in a logical order in the database It can either be sce or descending order What are database management system software 2mks A collection of programs used to store amp retrieve data and manage files or records containing related information from a database b Give the two classes of database software 2mks PC based database software Are usually designed for individual users or small businesses e g Ms Access Dbase Paradox FoxPro Corporate database software Are designed for big corporations that handle large amounts of data e g Oracle SQL Server Sybase etc 5 State the use of the following objects in databases 3mks i Tables To store related records ii Forms They act as screens for entering changing amp wewing data in tables iii Query Searching for specific records Data manipulation Selecting 6 a Define the term normalization as used in database design 2mks Normalization is the process of trying to eliminate storage of duplicate values in a database b State three objectivesjof normalization 3mks e To relate differefit tables in a database e To ease the retri yal of data from a relational database e Bxreakingup multi theme tables into smaller workable tables 7 Give three advantages of separating data from the applications that use the data in database design 3mks e You can re
74. isks Fixed mAN inside the computer system unit e g Hard disk mov isks are not hosed inside the system unit amp are portable e g floppy disk Ne Zip disk flash disk CD R CD RW DVD Explain the following storage devices i Hard disk A fixed storage device housed inside the Computer System Unit ii Flash disk 23 24 A high capacity plug in portable storage device Usually attached at the USB port of the computer iii Zip disk High capacity disk that resembles a floppy disk but is slightly larger and thicker in size a Compare a floppy disk and zip disk in relation to size 2 mks A floppy disk is physically small in size and capacity while a zip disk is slightly large in size and has large storage capacity amp ay Give three disadvantages of floppy disks as kA Floppy disks are slower than hard disk Highly affected by viruses Low storage capacity QS Not reliable Affected by Ke2 al factors exposure to sunlight magnetism and dirt a Stat hr Grises of using hard disks as medium of storage he T vide permanent storage of data They have a large storage capacity Are cheap per unit of storage Are rewritable provide read amp write facilities Are very fast compared to other secondary storage devices in terms of data transfer 25 26 b Describe three precautions you would take to avoid damaging the hard disk 3mks Do not drop the disk drive Do not expose it to strong he
75. ission over the next portion of the network Signals become weak due to attenuation 8 List two advantages of cell phones over fixed lines 2mks e Are cheaper than fixed lines e Less prone to transmission errors e Can be used even where there are no telephone lines e Portable i e can be carried around 9 a Study the diagram below and answer the questions that follow Ne 10 i ii a b Name the communication media depicted in the above diagram 1mk Satellite communication Name the parts labelled A B C and D 4 mks Receiving earth station Satellite in space Down link LS Sf Up link RA List three advantages of the above ony edia 3mks S line of sight to each station Hence It is convenient because it provides there is no need to keep on QU dish so as to track the line of sight Can be in very remote areas that d not have high cost physical infrastructure like telephone lines Sie 2mks Define OS topology 2mks two logy refers to the arrangement of the computers printers and other equi t connected on the network Distinguish between logical and physical network topology 2mks It is fast e Logical signal topology deals with the way data passes from one device to the next on the network e Physical topology refers to the physical arrangement layer out of devices on the network APPLICATION AREAS OF ICT Write in full hence explain the term ICT 2mks
76. ite operation Water causes rustling of metallic parts and short circuits if used 27 28 29 a State one reason why a computer needs to be connected to a stable power supply b 1 mk To prevent damage to the computer s secondary storage media To avoid damage and loss of important data or information such as application software stored on the media Prevent loss of data information that had not been saved 7 List down four functions of the ve 4 mks It prevents sudden power surges that might d computer It supplies power to the Computer duri It provides stable clean power i Alerts the user of power uts and brownouts ping Allows the user to saye his her work and switch off the system using the correct procedure Mention two thin likely to cause strain in the computer room or Q the room Bri onitors Flickering monitors Very bright wall paints reflect too much light Identify three proper sitting postures while using the computer Adopt relaxed and straight back position to avoid bending forward or learning far backwards 30 31 The feet should be firmly placed flat on the floor The seat must be high enough allowing the eyes to be the same level with the top of the Screen The seat must have a straight backrest that allows someone to sit upright This prevents muscle pains amp backaches caused by poor sitting posture The height of the chair or working surface mu
77. lation as compared to manual worksheet Has inbuilt formulae called functions that are non existent in manual worksheets Uses the power of the computer to quickly carry out operations Has better document formatting amp editing qualities than a manual worksheet Utilizes the large storage space available on computer storage devices to save amp retrieve documents Can easily be modified while manual spreadsheets involve a lot of manual calculations amp are very difficult to amend The user can very quickly amp efficiently perform complicated computations using the information stored in an electronic spreadsheet Enables the user to produce neat work Offers graphical representation of data leading to comprehensive decisions It is accurate in its calculations amp allows automatic recalculation_omformulae For a manual worksheet changing one value means rubbing the result amp writing the correct one again 4 Explain five application areas where spreadsheet Software can be used 1 ii iii iv 5mks Accounting spreadsheet softwafe cam be used by accountants to record their daily transactions amp also keep financial records e g they can record sales amp purchases preduce invoices compile financial statements calculate profits prepare budgets gete Data management a spreadsheet enables data amp information to be asrangedmeatly in tables produced easily and also kept up to date e g one
78. learn how to install and use the program LS e Operator oriented documentation It ww at enables the user to learn how to install and use the program Programmer oriented docume is is a detailed documentation written for skilled programmers the necessary technical information to help the programmer 4 dification of the program State three types of control structures use in programming 3mks Sequen Se cision amp Qorin b Draw a simple flowchart diagram to illustrate the FOR DO structure 3mks Boolean Expression amp rm structured programming 2mks 16 a fine This e technique of program design that allows large programs can be broken down into smaller components sub programs called modules or sub routines each performing a particular task b List any two characteristics of Structured programming 2mks Modules or sub routines Use of control structures in problems solving 17 c a b Give two benefits of structured programming 2mks Breaks splits a large program into smaller sub programs modules each able to solve a particular specific problem Structured programs are easier to read They are easy to code and run Programs are easy to modify because a programmer can chandEies of a section without affecting the rest of the program Modules are easy to test amp debug i e correct wo This is because each module can be designed coded amp
79. lementation and maintenance Program documentation a Give two reasons why it is necessary to have a program design 2mks It identifies the exact order in which the processing tasks will be carried out so as to solve the problem e It provides for easy maintenance amp modification b State two requirements during computer program testing 2mks Compilation to check the whole program if there are any errors Debugging the program a State any four rules guidelines that should be follow airing AS 4mks g point and one exit point program flowcharts e A flowchart should have only one en e The flowchart should be clear e Use the correct symbol xO e in the flowchart e The flowchart s t pen to more than one interpretation asy to follow e Avoid overl g the lines used to show the flow of logic as this can cre Q n the flowchart arison instructions simple i e capable of Yes No answers e N gical flow should be clearly shown using arrows e Ensure that the flowchart is logically correct amp complete b Give one advantage of pseudo codes over flowcharts 1mk e Pseudo codes are easier to write and understand e They are convenient especially for long algorithms which span over several pages 12 Explain the following types of computer program errors a Syntax error 2mks These are programming errors mistakes that occur due to incorrect improper use of the grammatical rules of a pa
80. lication software together with the associated documentations ii Data processing managers DPM 2 mks A data processing manager is the person who usually isin charge of the overall running of the data processing department in an organization He plans monitors and controls the persomnel ensures that resources and labour are available as required and interfaces tosisers 2 Differentiate between software engineer and a computer engineer 2 mks Software efiginceendevelops software programs as per requirements computer engineer designs computer hardware and improves on existing ones 3 a Sate three public universities where one can further her computer studies 3 mks Nairobi university Moi University Kenyatta University Jomo Kenyatta University of agriculture and Technology JKUAT Egerton University Maseno university b Identify at least three related courses offered at i College level Certificate in information technology Diploma in information technology Diploma in Education computer science ii University level Bsc Computer science Bsc Information technology Msc Information systems a Name three responsibilities that Cy ut by a Develop amp test websii 3 Maintains CA odifies information on the websites to meet new demands by the users nito access amp use of internet connection by enforcing security measures Do ds information needed by an orga
81. ller computers like Laptops tend to be more expensive than Desktop computers The technology of producing smaller devices is expensive They are convenient because they are portable They have advanced power management capabilities Co less power since a laptop can operate on rechargeable bat Which category of computers would you wA series Nokia phone Microcomputer palmtop Q is regarded to be a computer uses ctric energy to operate Give three reasons wh It is electroni It has a y unit screen Ith d Q memory for storage programmable a Mention three Analogue devices Computer used to control a flight Simulator for training pilots Bathroom scale z Thermometer 15 Speedometer z Post office scale 2 A radio with a knob that slides in a slot to increase volume b Give three example of special purpose computers Robots Mobile phones used for communication only Calculators that carry out calculations only ASS z Computers used in digital watches amp in N Computers used in petrol pumps Computers used in washing m An automatic pilot A word mon D State a specific examp a Gst Petr research Defense and weapon analysis ere each of the following types of computers can be used Aerodynamic design and simulation b Mainframe computer 1 mk Banks for preparing bills payrolls etc 16 Hospitals Airport
82. m amp time wastage especially when searching for a particular item In order to carry out any file processing task s all the related files have to be processed Misleading reports due to poor data entry and organization Difficulty in sorting retrieving amp updating records amp Security no protection of files against a De Sharing of files is difficult EN Some information resulting from several file ot be available List any two methods used S in a database 2mks Password protection User and group permi User level oF Data e The following car details are to be entered in a database Make Date of manufacture colour and cost Prepare a suitable database structure showing field names and their field data types 5 mks Field name Data type ID Primary key Auto Number b c d Make text Date of manufacture Date time Colour Text Cost Currency Explain how you index the data such that cars of the same make and colour are together 2mks Create a query to show same make and colour K 1 000 000 3mks Write a statement that can be used to select cars of colour A 2mks D Create a query In the colour field and in the Criteria r Give an instruction that would i Select cars whose cost is between 500 Create a query In the cost field criteria row write gt 500000 ost 2 cars 3mks ii Determine the averag 1 Create a query O verage of costs Avg opti
83. mponents or other systems that communicate with each other Inputs and outputs a system communicates with its environment by receiving inputs and giving outputs E g a manufacturing firm gets inputs in form of raw materials from the environment and transforms them into finished products which are released into the environment Process a system usually transforms or processes data from one state to another System entropy decay a system must have controls which help it not to operate beyond its boundaries The controls enable the system to adapt togehanges in the environment in order to give the expected output or to perform tothe expected level 4 a Define the term information system 2mks An information system is the arrangemefit of people data processes and information that work together to support and improye the day today operations of a business b Highlight three circumstances that necessitate the development of new information systems 3mks e New opport inities a chance to improve the quality of internal processes and service delivery in the organization may arise eA Invention of new systems which are more successful than the existing ones e Problems the user may encounter some difficulties in the operations of the existing system e Directive these are requirements imposed by the management government or external influences 5 State four roles functions of an Information system analyst 4mks e Examines t
84. n or organization having it Data should not be transferred to tries without the owner s permission Do not collects irreleva An individual has a right to lemand guarantee to privacy of personal information stored s on a computer Give Q xO Dat irth too much information for a purpose types of information 3 mks ID Number Residence Address Phone number DATA REPRESENTATION IN A COMPUTER With the aid of a diagram explain the difference between a digital signal and an analogue signal 2mks An analogue signal is continuous in nature while a digital signal is in discrete form TH Analogue signal sine Waves N L Digital tangular shaped Explain the role 6 s communication 2mks A modem conv les data from digital to analogue form to be transmitted over the h ng At the receiving end the modem attached to the receiving computer converts demodulates the analogue signal back to the original digital form Explain each of the following computer terminogies as used in data representation 4mks 1 bit The smallest binary unit 0 or 1 ii Byte A group collection of 8 bits used to represent a character iii Nibble a group of four binary digits usually representing a numeric value iv word The total number of bits that a single register of a Gy machine can hold State two reasons for using binary in digital tech It is easier to develop de
85. ng a program for logical N ing the corrections on a paper or from the printouts G tes should not be used in the computer representing two states of data such as OFF amp ON A computer teacher has put a rule a Give a reason for e To preven of viruses between the computers laboratory pre authorized copying of programs from or to the computers Stu may carry immoral files using the diskettes b State two alternatives that can be used to achieve the same objective 2 mks Using diskless computers Use of antivirus software to detect clean viruses before use List three differences between a laser printer and a dot matrix printer 3 mks Laser printers are faster than dot matrix printers Laser printers are quiet while dot matrices are noisy Laser printers use thermal technology while dot matrix is an impact printer Laser jets use Toner cartridges while dot matrix use ribbons Data collection preparation oO a What is a AO This is a p ed frequently by the computer to carry out routine jobs ility are is used to manage computer files diagnose and repair computer pro and assist in helping the computer to run more efficiently b Give four examples of utility software A laser printer is expensive than a dot matrix The print quality of a laser printer is better List four stages involved in the data processing cycl 2 mks Data input Processing Output of info
86. nization or institution from internet websites ii Computer trainer i Web administrator Training people on how to use a computer amp the various application programs Development training reference materials Guiding learners on how to acquire knowledge through carrying out research Advising the learners on the best career opportunities in the broad field of ICT Preparing learners for ICT examinations Explain two factors one would consider before enrolling for an ICT course in a college The cost of the course Marketability of the course i e whether it offers courses recognized both locally and internationally Basic course requirement e g qualifications Job opportunities S QS ae V K C S E SAMPLE PAPER Kenya Certificate of Secondary Education 451 1 computer studies Paper 1 theory 2 hours This paper consists of TWO sections A and B Answer ALL the questions in section A A Answer questions 16 and any other THREE questions fr Q B FOR OFFICIAL USE ONLY INSTRUCTIONS TO CANDIDATES V SECTION TION SCORE z her 16 Ve 18 19 20 TOTAL SCORE SECTION A 40 marks Answer all the questions in this section 1 Computer systems are built from three types of physical components processors memories and I O devices a State two tasks of a processor To fetch data amp information from memory Decode
87. nnected to it while parallel cables usually offer 1 way communication b Give two major advantages of a USB interface cable over other cables in the computer It is light amp convenient to carry It provides faster transmission of high quality data Its serial nature enables it to connect devices a longer di y _ The USB port can be used to connect a aN common universal interface Outline three precautions one should ripheral devices due to its assembling a computer Disconnect all diverts fr er source before starting to work on them Never work alone be ay need help in ease of energy se y Discharge ant e icity that might have built up on the hands by touching an earthed me State AY which you would consider when selecting computer hardware for an organization ct and wearing an anti static wrist member Cost of the system Processor type and speed Storage capacity of hard disk amp RAM memory size Warranty service contract 51 52 Upgradeability of the computer Compatibility of the system Portability light to carry User needs Popularity of the hardware manufacturer Availability of spare parts Multimedia capability amp List down any four hardware components you can KA N a computer system Q 4 mks Processor CPU Ports e g USB ports SCSI ports ey Hard disk Qs DVD drives tape dri RAM memory or Expans
88. oke down due to the excessive heat generated hence were short lived and were not very reliable Their internal memory capacity size was low Processing speed was very slow Very costly Used magnetic drum memory Briefly explain the classification of computer according to historical development generations First generation computers Used vacuum tubes in their memory Large in physical size consumed a lot of power Produced a lot of heat LS W excessive heat generated le hence were short lived and were not Q Their internal memory capacit s low Slow in processing data The computers constantly broke dow Very costly Used magnetiedrum memories k C o enter data into the computers Second ner omputers Ne transistors in their memory They consumed less power amp produced less heat than the first generation computers They were relatively faster than the 1 generation computers Used magnetic core memories Were less costly than first generation computers RAM memory capacity was 32 KB Third Generation computers Used integrated circuits in their memory They were faster than second generation computers RAM memory capacity was 2 GB Slightly smaller in size than 1 amp 2 generation com They used a wide range of peripheral devices Could support remote communication fi e than one user at the same time Magnetic disks were introduce ge purposes Fourth
89. on in the total section and lt 1000000 DESKTOP PUBLISHING DTP 1 a Define the term desktop publishing 2mks The process of producing publications such as newspapers books newsletters cards etc by marking areas for text and graphical objects using specialized programs installed on a desktop computer b Give any three examples of desktop publishing software gt in the market today ks Adobe PageMaker AS Adobe Photoshop Adobe illustrator Ventura Microsoft Publisher CorelDraw aie pes of publications that can be produced using desktop 2 4mks Cards e g for special occasions such as weddings graduations congratulations etc Newsletters Newspapers Calendars Advertisements Posters a b c Differentiate between the following OX O Magazines Certificates Notices Catalogues Pamphlets Books Brochures Pasteboard and printable page 2mks Pasteboard is where text amp objects are place g before transferring them to the printable area Printable page refers to nclosed in margin guides g9 uide 2mks 2mks Margins and colum Margins mark t divide the A S ang and drop cap 2mks N is changing text from upper to lower case sentence title or toggle case while drop cap refer to making the first character in a line bigger and drops down to on the page along the edges while column guides everal fields The
90. oot cable problems If two machines are not communicating the administrator will only check the cable between them Enhances flexibility in communication LS A Enhances fault tolerance provided by Bka ks Q Difficult and expensive to install ain A A of cables or redundant links nodes when the network is large Difficult to add mor Difficult to isol ue to lack of a central control point a cong decided to computerize their operations They have decided to Disadvantages Very costly as it requir purcha ckages instead of developing their own programs Give three advantages and two disadvantages of their approach 5 mks Advantages of packages They are cheaper to purchase as the cost of developing them is effectively shared between the purchases There is saving of the programming effort because the company buys the software when ready made Packages are thoroughly tested Relatively quick results are obtained Disadvantages of packages The purchaser is not in direct control of the software because is not involved in N Packages are produced to meet general needs KA deal with the specific user e to the application of the developer s developing it or company needs Packages cannot be modified custo Os may not be required by an individual user or copyright acts Packages include extra company Packages may y aclumsy solution to the task at hand
91. ow m ch data the disk can hold can also check for bad sectors on the new disk 23 a What is meant by the term disk partitioning It is the process of dividing a large physical disk into 2 or more partitions volume b Give two reasons why the hard disk may be partitioned To install more than one operating systems on the same disk 24 25 State two purposes of the re ycle For the purposes of backup on the same disk so that if one partition fails the other will still be working A Form four computer student is attempting to print a programming documentation The printer is not responding to the print command Explain three possible causes for the anomaly 3 marks The printer may not be installed The printer may not have been set as the default printer N The data interface cable to the printer could be WX ure it is firm at the ports The printer could still be off Switch it on a ill start printing The wrong printer could have been sel box and send the print job again we 2 marks ect the right printer in the print dialog Contains the fil ers that have been deleted Can be use f files amp folders accidentally deleted from the computer V a b Give three comparisons of th WORD PROCESSING What is a word Processor 1 mk A computer program that enables a person to create retrieve edit format and print text based documents List two common ex
92. p less space Easier to update and modify Provides faster access and retrieval of data Reduces duplication of data or stored records Cheaper Enhances data integrity i e accuracy and completeness 11 12 Bit 13 Distinguish between logical and physical computer files 2mks e A logical file is viewed in terms of what data items it contains and what processing operations may be performed on the data e A physical file is viewed in terms of how the data items found in a file are arranged on the storage media and how they can be Gey Arrange the following components of the informati ta hierarchy in ascending order of complexity Field Database Byte Record Bit and file gt Byte Qh Database 4mks In a computer based i on system state the purpose of the following files and give one example whe amp 8mks 1 Report file It contains a set of relatively permanent records extracted from the data in a a file may be required in a school master file They are used to prepare reports which can ve printed at a later date e g report on student s class performance in the term extract of students who have not cleared their school fees report on absentees 14 ii iii iv a b i ii Backup file Used to backup data or to hold duplicate copies of data information from the computer s fixed storage or main file for security purposes e g a copy of all the
93. page single sheet stored in a workbook Name four data types used in spreadsheets 2mks e Labels e Values e Functions e Formulae An Agrovet Company wants to analyze its employee s personal details using Microsoft Excel The company has five employees Mary Anne Francis Kihara Lena Achieng Hellen Wanjiku and mwangi Peter Their ages are 20 45 90 45 and 34 years respectively Mary department Mwangi Peter in finance department and Hellen Wanjiku in Computer department Mary Anne and Hellen Wanjiku are single whereas Francis Kihara Lena Achieng and MwangiPeter are married Construct a worksheet showing the above information Use appropriate column headlings 6mks 10 A B C D 1 AGROVET COMPANY 2 NAMES AGE DEPARTMENT STATUS 3 Mary Anne 23 Research Single 4 Francis 45 Personnel Married Kihara 5 Lena Achieng 90 Research ied 6 Hellen 45 a ie Ni ingle Wanjiku RA 7 Mwangi Peter 34 Geom Married D a What isa cell ref e 1mk A cell reference is y of a cell in a worksheet A cell is identified by use of the column letter Q row number headings b For each of the following state the type of cell reference 4 mks i AS Relative reference il F 5 Absolute row reference only the row reference is absolute ili H 21 Absolute column reference only the column reference is absolute 11 12 iv a b c Differentiate betwe
94. ple in each case explain the AtA p of operating systems a Single user single tasking A system that allows only one user t ser program at a time in an interactive conversational mode E g Ms DOS b Multi User Multi king A multi u Py system can allow interactive facilities to several at a time A Multi puter system can allow more than one program which are in the ory processed at the same time E g Microsoft Windows Linux A computer user may interact with a computer either through Graphical User Interface GUT or though typed commands a Give one advantage of using GUI based operating system over a command line interface 1 mk User friendliness Easy to learn amp use even by those who do not have much knowledge about them One does not need to master any commands It is faster to work with than a command line interface as it only relies on clicking the icons by use of a pointing device b Some computer systems still use command line interfaces State two advantages of command line interface They are more flexible than menu driven interfaces amp es will access There is security of data as only those who know iow 9 it A They use cheap hardware amp software facili amp One has a better control over the syst es What is a deadlock in refe AS systems It is a situation in an hen a particular task holds a needed resource and refuses to release it for u tasks Exp bri th
95. position of the end of the file market 1 mk The end of file marker is the position immediately after the last record i e position 11 b State the purpose of each of the following i File server software Controls access to avail files stored on a networked shared storage location Services client requests for files ii Communication software Used for receiving sending messages or data in a network Used for routing traffic amp Used for assigning identities to nodes LS lt a Name the control structure depicted by the fl gt lt V Selection control structure e g If then else b Explain the following terms as used in program implementation 2 mks i parallel running This is where both the existing and the new systems are run concurrently simultaneously at the same time for a period of time until users have gained confidence in the new system Data is processed on both systems in order to compare their performance and also cross check the results V e new system in one bold ii Direct change over This is a complete replacement of the existing s move The existing system is stopped amp O d the new system starts q9 operating immediately 8 Consider the linear ar i AA 5 50 aw ili Find 9 of elements in each array 3mks AAA 5 50 50 5 1 46 BBB 5 50 10 5 1 16 CCC 18 18 141 18 cannot be determined Define the term a
96. prevent unauthorized access of data in a computer iii Dry run and walkthrough Dry run is where the program is tested on paper before it is keyed in Walkthrough is a style of evaluating a program by a team of p Qj which in turn reports to the programming team AV O b Draw a labeled diagram to illustrate the inte N of a diskette 4 mks aa Track 0 at the edge of the disk Hub Information stored on many concentric tracks c Give two diffe s between post Office Mail electronic mail E mail 2 mks Post office mail is operated manually Email is computerized Post office mail is slow email is fast Email has a wide area of coverage Email is more secure d Speed and accuracy are some of the advantages of using computers in banking State three other advantages of using computers in banking 3 mks Makes it easy to access information It is easy to update records requires less space for storage of documents Improved data security amp privacy S QS ae V K C S E SAMPLE PAPER Kenya Certificate of Secondary Education 451 1 computer studies Paper 1 theory 2 hours This paper consists of TWO sections A and B Answer ALL the questions in section A A Answer questions 16 and any other THREE questions fr Q B FOR OFFICIAL USE ONLY INSTRUCTIONS TO CANDIDATES V SECTION TION SCORE z her 16 Ve 18 19 20 TOTAL SCORE
97. printer machines Plotters produce information in an easily understandable form Their presentation is quick amp reliable Produces large graphical designs of high quality which are east to read amp use Can print on large sized papers e g papers e g Al Which a A ji cannot g O S ters away from the computer Very fast making it useful in emergency situ One can receive the output even when No reading ability is required of _t Suitable for the blind and People with poor sight Can be used for distanco CA ed e g if used in a camera one know when the film or ication if done over telephone lines Errors are easi exposure i Ko interesting and entertaining George connected new multimedia speakers to his computer and tried to play his favorite music CD but no sound came out Suggest two problems that might have occurred 2 Volume control was too low Loose or improper connection to the sound card 44 45 Speakers not powered Multimedia not supported Lack of analogue cable connecting the optical drive to the motherboard or sound card Sound card drivers not installed List down 4 factors to consider when buying an output device a b Define the following terms QS The volume of the data The speed at which the output is required OX Cost of the method chosen as compared with N e derived Suitability of the application Whether a printed version is required Port A spe
98. r e g the computer reads data from a disk a keyboard etc gt To move or copy data from backing storage to the main Storage b Write To transfer information from the computer to an output Device e g the computer writes output on a printer or onto a disk To move or copy data from the main storage to a backing storage 5 State four different parts that make up a computer 2 mks System unit Monitor Keyboard Mouse Printer Modem Scanner Speakers Graph plotters 6 a Explain the term system Unit b This is the casing that h s rnal components of the computer such as the CPU and storage devices List O AA under the cover of the system unit processing Unit CPU e Power supply unit Main memory Hard disk Disk drives Battery Buses Input output ports Video card Expansion slots c Give two differences between tower style and desktop system units Tower style system unit is designed to stand alone or Cy on the floor A desktop units lie on the desk with the monitor pl S the typical desktop units z Tower style units have more space for IN 7 Computers have evolved through a O generations List any 4 characteristics of the first generation of compu A Large in physi al siz 2 mks Relied o ic valves vacuum tubes to process and store data Co ot of power Q a lot of heat Ng computers constantly br
99. r individual Browse Surf the web Moving around and between the What is meant by the Q ing 1mk This is learning through interaction with special programs on the computer co A school X an e learning system List three problems that are ikely t countered 3mks 2 mk Lac apital Lack of skilled manpower required technology to run amp support the e learning system Spread of computer viruses Availability of pornographic material amp literature to the students from the internet a b Identify the parts of the following e mail address labelled A B C and D 4mks lat africaonline co ke rc 2 A B C D N A Name of the individual or organization RA B Name of the host computer in the 9 ich the e mail account is hosted C Identifies the type of the n or institution offering a particular service i e commercial D Name of the country re the site is located i e Kenya Mention t Qoo O express les of e mail software 2mks Microsoft exchange Eudora Discuss four advantages and two disadvantages that electronic mails have over regular mails 6mks Advantages 1 Cheap amp economical It costs almost nothing to transmit and e mail ii iii iv v vi message over the network There is no need for stamps envelopes etc Secure Access to a user s mailbox can be restricted by use of a password Faster The delivery of an e mail m
100. radiation from the monit at reaches the eye Controllin intensity by adjusting the brightness buttons on the screen iting Qi so as not to face the user directly We special spectacles when using computers in order to control the light intensity Avoid using flickering monitors as they can cause extreme eye strain that can damage eyesight Very bright wall paints reflect too much light into the user s eyes Taking frequent rests b List three factors to be considered when deciding on the choice of an electronic data processing method c Type and size of business Timing aspects of the information produces Link between applications Volume of data records held in the organization Cost pf acquiring the relevant hardware software storage ASJ cost of maintenance Operation speed A Quality of output required Explain time sharing data proc de giving two advantages and two 6 mks disadvantages Qs Time sharing is a prog ssing Mode where a central processor services 2 or more users who have di K ements Advantages Marine AN oo idle time This is because the processor doesn t have to wait for the slower commutating peripherals Helpful to small companies which cannot afford purchasing a computer amp the related facilities The company can be served at a fee through time sharing processing mode Provides better services to the user since the output is fast Files are held online
101. rmation Text editors Sort utility Language translators 10 Merge utility Loader Copy utility Linker Dump utility Diagnostic tools Database management system Distinguish between an intelligent terminal and du An intelligent terminal is one which is PS ae some limited amount of processing on data before transmittin yond their processing abilities to the central computer A dump terminal is on Se c have any of its own processing capabilities power It relies on thegrocessimg capabilities of the central computer that serves it List two duties of a Database Q irior Des develops database applications for the organization ing personnel Installs amp co ordinates database systems Updates the database by adding new record modifying the existing records amp deleting the unnecessary records Responsibilities for the security of data in the database i e designs amp sets up security measures needed to control access to the organization s data Ensures the database meets the information needs of the organization Ensures facilities for retrieving data and structuring reports are appropriate to the needs of the organization Responsible for documenting the manuals for users b Data processing manager Ensures that the organizational information needs are met In charge of the overall running of the data processing ts e g he is in char
102. rmed on a relational database files 3 mks Indexing Sorting Filtering Querying Updating of records Report generation V List three parts that constitute an array definition s 3 mks Array name S Range which contains the initial value inal value Data type E g Score Array 1 50 Qh amp SECTION B 60 marks Answer question 16 and any other three questions from this section 16 Bidii wholesalers has two categories of customers for order processing category A obtains 10 discount on all orders up to Kshs 10 000 otherwise the discount is 20 on the entire order Category B obtains 30 discount on all orders if the debt repayment is good otherwise the discount is 15 Draw a flowchart for the rdemprocessing 15 mks qav ua noy READ customer name category Amount order number NO Category A YES READ Credit status Amount 10000 YES f Amount Amount 75 Amount Amount 80 Amount Amount 80 Amount Amount 90 rly PRINT Customer details Amount 17 a List three application areas of artificial intelligence 3 mks b Expert systems e g medical diagnosis engine repair legal defense etc Natural language processing Artificial neutral networks e g investment analysis signature Analysis etc Robotic perception systems With the improvement in price and performance of computersgand communication equipment it
103. rs amp printer toner because errors on the printouts that may require reprinting will be minimal Distinguish between Portrait and Landscape orientations 2mks In Portrait text amp graphics are printed with the longest side of the page vertically upright while in Landscape text amp graphics are printed with the longest side of the page placed horizontally b State two reasons why it is necessary to specify the correct paper size before printing a document 2mks e Select a paper size depending on the document page size needed e To comply with printer capabilities 23 Outline any three main features that make word processo programs A 3mks e Saving of documents for future refere e Printing of multiple documents a e formatting of document quited form e Mailing features su a mail merging of standard document with another saved file SPREADSHEETS What is electronic spreadsheet software 2mks e A computer program that looks like the manual ledger sheet with rows amp columns for entering data that can be manipulated mathematically using formulae Give any two application programs classified as spreadsheets 2mks e Microsoft Excel e Lotus 123 e Corel Quattro Pro e super calculators e Multiplan e VP Planner S e VisiCalc 4 analysis ledger sheet and an electronic Differentiate between the traditi spreadsheet 5mks An electronic Q H worksheet for data entry amp manipu
104. rticular language E g Punctuation mistakes i e omitting a comma or a semicolon improper naming of variables wrong spellings of user defined and reserved words b Logical Errors These are errors that occur as a result of bad programpde sign Logical errors relate to the logic of proc ssingstollowed in the program to get the desired results e g they may o euras a tesult of misuse of logical operators c Run time execution efror 2mks Run time exegution efrors They occur when the programmer develops statement which are not projecting towards the desired goal Such statements will create deviations from the desired objectives 13 Explain four error detecting methods in program development 4mks 1 Dry running desk checking checking a program for errors by making the corrections on a paper before entering it in the program editor ii Translator system checking It involves the running of a translator program e g compiler or Interpreter after entering the set of coded instructions in order to detect any syntax errors 14 15 iii Use of debugging utilities It involves supplying data values to the program for which the answer is known If the program does not give the correct answers it shows that it contains some errors Describe three types of program documentation in reference to programming i ii iii a 6mks User oriented documentation It is a manual that ena user to
105. rtificial intelligence 2mks 10 11 b c 12 Artificial intelligence is the development of machines that imitate copy human like qualities in particular areas e g learning reasoning communicating seeing hearing and self correction These are programs that make computers to mimic human intelligence A study in which computer systems are made to think act imitate human beings Name two types of relationships that can be applied in database sion 2mks One to one One to many Many to One My Many to Many Explain the following terms as used in wor 3 mks Se from the left or right margin egin Leaving a space at th Alignment Q sey positioned lined up in a paragraph relative to the left right or tre age Word o gt A facility that word processor use to automatically move the text cursor to the a Indenting It is moving of line par of a line paragraph of text from the margin Refers to beginning of the next line when it reaches the right margin automatic rolling of text to the next line when you reach the end of the line Outline two ways in which computers can be used in hotels 2mks e Reservation booking of rooms Record keeping on sales and purchases stock control Producing bills amp payrolls Marketing and advertising Communication Security 13 a Explain binary coded decimal code of data representation 1mk This is a data encoding system that uses
106. s i e in Airline reservation systems for booking amp storing flight information Communication networks as servers c Minicomputer 1 mk Scientific laboratories amp research institutions Engineering plants for controlling chemical or mechanical Gy y Space industry OX i l a Insurance companies amp banks for accounting EA Communication centers as servers d Microcomputer personal comput 1 mk Training amp Learning QS schools as termi Communication cent Small A Q s e g shops small offices and homes a Define a T a d 1 mk Ww who s CPU processor has been implemented with a microprocessor b Differentiate between a microcomputer and a personal computer 2 mks nals A microcomputer is larger in physical size than a PC A microcomputer is more powerful than a PC A PC was designed to be used by one person only 17 18 c List three factors to be considered when purchasing a microcomputer 3 mks Type of processor Processing speed Amount of main memory RAM Storage capacity of the hard disk Cost of the computer Speed of output devices LS Number of users who can access the computers uN ime Explain four reasons which make microco uitable for personal computing work Reduced cost i e are cheaper tha y R gt space i e consume less power icomputers amp mainframe computers Have high processing s
107. s a sequence of values cell references functions and arithmetic operators whose calculations results to S gt b Consider the entries made in the cells below A a numeric value Cell B2 B3 C10 C11 C13 Entry 200 100 B2 B3 C1l0 D ALUE State the value displayed in c 2 mks It returns an error mes age 8 List three ans Wide Area Networks WAN and local Area Networks L 3 mks LAN is limited to a small geographical distance Data transmission speed in LANS is higher Cost of data transmission in LANs is small There are less transmission errors in LANs 9 10 11 Study the flowchart segment below and state the last value printed from the flowchart O SS O S AN a What is an expert system 1 mk an that mimics human expertise in a particular area of specialization i b State any eren hanism for making decisions Kno ge base Explanation facility An expert system is co onents of an expert system 2 mks User interface Give reasons why optical disks are better storage media compared to floppy diskettes 12 a b c d 13 What are DOS commands used for the Q Changing directories O Have a high storage capacity More secure against alteration i e they require writers to alter their contents More robust i e can resist temperature electromagnetic fields and
108. s instructions Execute runs programs N Controls hardware operations through sending ae als b State the functions of I O devices Transfer information into amp out O uter q amp the computer uni Threats to th of computer system take many forms such as white collar Serves as the interface Enables the user to c e with the computer DOA vandalism and carelessness Give on y as to how each of these forms of threat can be controlled 2 mks i White collar crime Use of policies System auditing and use of log files Use of passwords putting in place punitive measures Data encryption Use of firewalls ii Natural disasters Use of UPS Use of backups Installation of lightening arrestors Having standby fire fighting equipment Use of fire proof data saves Contingency plans iii Vandalism Tighten security a alarm systems fitting burglar proof doors Punitive measures iv cate WO tter of personnel Imp employee training and Education Plus Agencies Limit access to data and computers Regular backups Use of UNDELETE and UNFORMAT utilities a Explain the term nibbles as used in data representation in computers 1 mk A nibble is a group of 4 binary usually representing a numeric number b Perform the following binary arithmetic giving the answers in decimal notation 3 mks i 1110 0111 1101001 11 1110 0111
109. st be high enough such that your forearms are parallel with the floor and your wrists are straight The seat must be high enough relative to the table to enable theuser use the hands on the peripheral devices comfortably State two methods of minimizing dust in a compufer laboratory Fit the computer room with special curtains toeeduce entry of dust particles Cover the floor with carpets in order tojabsorb dust Regular cleaning of the Jaboratory Cover the computer devices with dust covers when cleaning the room Name two main causes of fire in the computer laboratory and give the precautions that should be taken to guard against them Inflammable chemical such as those used to clean the computer equipment Keep the chemicals away in store after use Open wires cables Ensure that all electrical wires are properly insulated Ensure that the computer room has a gaseous fire extinguisher containing carbon dioxide in case of any accidents 32 33 34 Smocking What is the purpose of labeling a diskette To prevent confusing the data in the different diskettes To prevent mixing diskettes that are used everyday with those used for long term storage of important data List three things that can spoil a printer if they are not of ct specification and explain what damage may be caused RA i Printer Paper Different printers have differ ity to printing papers Using the wrong quality paper in a partic
110. st pointi screen and selecting options A Can be used to draw images on the screen e It is light and easily portable saves A light pen will result in few err 7 a What are computer scanni i 2 marks These are devices thaenter ture data into the computer directly b Name the type of s sed 2 marks i To capture p ods at points of sale terminals in supermarkets and superstores Ne ii To grade multiple choice examination Optical mark reader OMR 12 Computer studies c Mr Otieno a French teacher used speech method to store students oral answers to an exam into a computer a What is a speech input It is a type of input where a microphone connected to a computer system is used to enter data in form of spoken words into the computer b State two advantages and two disadvantages of using this method of data input mks Y se with impaired hands Advantages Voice input is fast Its suitable for people with special needs es Can be used in emergency situations a Voice input is complex to develop Disadvantages Voice input X care speech related problems such as accents tone etc The respon speech input devices are relatively slow st Q input devices can recognize a limited standard vocabulary of spoken wor d the voice of only one speaker Cannot differentiate words that have same sounds homophones State four areas where speech input
111. stitutions with many departmental offices Bureaus or communication cyber cafes Airline reservation systems LS gt List down two benefits and three risks that might Wica with the distributed data processing system ks Benefits QS The load on the host computer i uced The use of low cost minicomputers minimizes the cost in data processing Delays in data proce uced Provides better ser iQ the customers There Ne ase of system breakdown The design plementation of the system is less complex due to decentralization The level of expertise required is less e Data duplication is very common e Programming problems occur with microcomputers amp minicomputers e Security threats i e the data amp information sent one the network from one place to 9 a b another can be tapped or listened to by unauthorized parties More training is needed for the users involved It is expensive due to the extra cost of communication equipment Explain the concept of multi programming 2mks A Multi programming system allows the user to run 2 or more ys all of which Give two benefits that are derived from or 2mks are in the computer s main memory at the same time It increases productivity of a comp ter Reduces the CPU s idle Reduces the incidenc of peripheral bound operation 10 State at least ages of storing data in computer files over the manual filing system 4mks VW takes u
112. students admitted in a school fees report on absentees Reference file Used for reference purposes It contains records that are fairly permanent or semi permanent e g Deductions in caution money wage rates tax deductions employees address price lists etc Sort file used to sort rank data according to a given order e Cy position in a N What is file organization It is the way records are arranged laid out on file or any secondary storage device in a computer Differentiate between the oO ganization methods 4mks class of students Sequential and serial In sequential file organizati O the records are stored in the order they come into the file and l are not sort way a Pd indexed sequential In random file organization records are stored in the file randomly and accessed ecords are stored in a sorted order using a key field while directly while in indexed sequential the records are stored sequentially but accessed directly using an index PROGRAMMING Section A Define the following terms 3mks i Computer Program A computer program is a set of instructions that directs a computer on how to process a particular task E ii Programming Programming is the process of designing a set Sau which can be used to perform a particular task or solve a specific s iii Programming language of instructions used in A programming language is a AS writing of
113. t the likelihood of a virus S Name the command one wo use to repair cross linked files in graphical user interface software CA 1mk Scandisk A a nam Disk Defragmenter and give two advantages of this feature 3 Vv mks Disk defragmenter is a tool that is used to re arrange scattered files amp folders on a storage media Advantages Rearranges scattered folders amp files on storage media Reduces the time by the read write head to locate files or folders on the storage media This speed up access to files amp folders hence makes files to open more quickly Consolidates related data close to each other hence frees space on the storage media b Distinguish between disk compressing and disk defragmenting Compressing is creating more space on a disk by squeezing disk contents files into a smaller storage location on the disk Defragmenting is rearranging scattered related files folders cloSergto each other on the surface of a storage unit 22 Give two reasons why a new disk must be formattedjbefore using it 2 mks To prepare a new disk so that files can be stored On it To create sectors amp tracks for the storag of data To create prepare a new root dire toryjand file allocation tables on the disk To remove delete any existing files or information stored on the disk if it is no longer needed To determine thefeffective storage capacity of the disk i e formatting enables the user to know h
114. tate six precautions that you would expect an organization to take to prevent illegal access to its computer based systems 6mks Lock the doors i e keep the computers in a trong room which should remain firmly locked when nobody is using it Avoid welcoming strangers into the computer room Use of personal identification cards Use of fingerprint idefittification Install secugity alarms at strategic access points so as to alert the security personnel in case of a break im UWse of special voice recorders that would be able to analyse the voice of a trespasser amp check against the database containing the voice patterns of valid users Enforce data amp information access control policies on all employees to control access to data Use file passwords to prevent any person from getting access to the electronic files Enforce network security measures e g use of firewalls Encrypt the data amp information during transmission e Perform frequent audit trails to identify threats to data amp information Give four rules that must be observed in order to keep within the law when working with data and information 4mks It should be kept secure against loss or exposure Should not be kept longer than necessary Should be accurate and up to date Should be collected used amp kept for specified lawful p A data should not be used for unlawful gain RY The owner of the data has a right to know O eld by the perso
115. tc Use of mouse pointer to drag an object on a form b Use application generators to generate program codes Can enquire amp access data stored in database systems List three examples of fourth generation programming languages 3mks Visual Basic Delphi Pascal Cobol Access Basic K N Describe 5 factors to be considered while cnosing pean language 5mks i ii iii iv v vii viii The availability of the relevant PN Whether the programmer is 4S e language lication areas such as education business Ease of learning and us Purpose of the program i e a scientific Execution igh level languages are easy to read understand amp develop hence Ne ss development time Machine code amp Assembly languages are relatively difficult to read understand and develop hence they are time consuming Popularity the language selected should be suitable and or successful in the market with respect to the problems to be solved Documentation It should have accompanying documentation descriptions on how to use the language or maintain the programs written in the language ix Availability of skilled programmers The language selected should have a pool of readily available programmers to ease the programming activity and reduce development time Differentiate between the following as used in programming a A source program is a program that is not yet translated Object code
116. tems N e Hospitals to monitor the progress of a pai o disadvantages of a real time system 5mks e Chemical processing plants e Missile control systems Provides u ormation is readily available for instant decision making Provides better services to users customers Fast amp reliable Reduces circulation of hardcopies Disadvantages Require complex Os amp are very expensive Not easy to develop i e Real time systems usually use 2 or more processors to share the workloads which is expensive e Require large communication equipment Differentiate between CPU bound jobs and I O bound jobs 2mks CPU bound jobs require more of the CPU time to process these jobs Gy the work the I O Most companies are now shifting from the use of PN distributed personal devices perform is on the Input and Output hence they CPU time computers This method of data processing is Distributed Data Processing DDP Required A Name any threes computing resourees that can be distributed 3mks CPU Processors re Files Application Q gt O Computer processing power Memory computer storage Input Output devices e g printers communication devices communication ports ii iii Risks Name four examples of industries and business organizations that extensively use distributed processing systems 4mks Banks Computerized retails stores e g supermarkets Learning in
117. the required position on the screen Used to move from one cell to another Used to move the cursor between options Used to indent text Enter key 2 marks ga al Q It is used as a RETURN Qe at the end of a text line or paragraph in a word processor it for es the text cursor to move to the next line or paragraph It is used tofi QE commands to the computer It is used to instruct the compute ut execute a command that has been typed or selected on the G vi Shift key 2 marks E It can be used for changing cases e g to get single capital letters It is used to get the punctuation marks on top of the Number keys or the symbols b on top of certain keys especially on the alphanumeric section Used for shortcuts in combination with other keys e g SHIFT DEL Simulation is one of the application areas of computers i What is meant by the term simulation 1 mark Simulation is the designing of models of either an actual or theoretical physical item and analyzing testing the execution output using a computer amp ii Name two application areas of simulation 2 In training of pilots using flight simulators RO In medicine to train doctors on operation O di roads and cars Design of bridges Aeronautical ering i e design of aircrafts To ina of traffic lights In engineering e g Architectural design of buil Design of electronic ci Alo si the
118. timing of a nuclear attack for testing national defences Ne training Laboratory experiments Missile launch Space exploration Vehicle accidents Entertainment e g games iii State three advantages of computer based simulation 3 marks e Saves cost it is an economical cheap way of testing models before actually building them e It enables the manufacturers identify weaknesses of the real situation or object hence e put the correct reinforcements to their designs e Reduces risks it allows some activities that would otherwise be expensive amp dangerous in real life situation to be put under test amp e Faster LS O e Convenient c Explain three ways in which computers have impaca education Standardizing learning Has ensured quality output A Brought the need for ret Enabled distance le g Created jobs e ter trainers Causes job ment and replacement Q 3 marks
119. tion while redo does the undone action iii Thesaurus It gives suggestion of words or phrases with similar meaning synonyms and sometimes antonyms to the selected word iv Autocorrect It checks for wrongly spelled words and automatically replaces them with the correct ones as set by the user 8 Give the steps you would use to find and replace the occurrence of a particular word in Microsoft Word 4mks Click on edit select find or replace Type the word you want to replace with in the replace with box Click replaces or Replace all if you want to replace all the ona Gy of that word in 9 Name and explain the use of any three buttons SS your document at once ell check dialog box 6mks Ignore Once Leaves t d error unchanged if the highlighted word i Q Ignore all T e occurrences of the same word or phrase in the document Change Accepts the uy in the suggestions box ord amp finds the next spelling or grammar error another language e g a Kiswahili Adds the highlighted word in the Suggestions box to the Custom dictionary 10 Clearly explain the meaning of the following terms as used in word processing 7mks 1 Editing a document Making changes to an already typed existing document 11 ii iii iv v vi vii a b Blocking text Selecting a group of text in order to work with it as a whole e g a word sentence or paragraph Printing ha
120. to new working areas as the computer may serve t0 penform tasks that may be performed by several people A recent breakthroughiin the manufacturing industry is the development of a full manufacturingslant that can produce vehicles using robots only a Give three advantages of fully automated manufacturing 3mks e Increases efficiency due to the balancing of workload and production capacity e Production increases in the workplace e Improves customer service e Enables production of adequate amp high quality goods in time Enables efficient utilization of resources e g raw materials personnel and equipment hence reducing operating expenses b State three other areas where automation is applicable 3mks food processing companies LS Intelligent control of traffic lights The autopilot in aircrafts Use of robots in industries Manufacturing industries such as vehicle assembly plants oil tefimeries and Discuss the applications of Artificial Intelligence in KAG llowing fields i Expert systems e In medical institutions for diagnosi ses In mining companies for pro minerals Financial forecastin ormelation of taxation amp marketing policies and making of investment decisions Financial fo ing e g formulation of taxation amp marketing policies and C stment decisions ii Ne processing 2mks It involves development of programming languages whether spoken or written This will make
121. trieve recorded data easily e You can do calculations in an easy way e Creating of queries forms reports will be easy by using data separation 8 Differentiate between i Primary key and relationship 2mks Primary key is a field or a set of fields that can be used to uniquely identify each individual record in a table It is used to relate a table to the foreign keys in other tables ii Tabular and columnar form layout mks Or and presenting a new record Tabular the records are displayed from left to right a KS e left the labels appear at the top of each column wit Columnar the fields for each record are di wn a column i e each value is displayed on a separate line with field 9 State three types of relationships that O d to link tables in databases Qs 3 mks 10 Explain how and child tables are related in relational database 4mks e One to One e One to ma e Many to Ap table is the one that has the primary key of the relationship while a child table is the one that has the foreign key of the relationship Parent and child tables are related through a common field that links the two tables Records in a child table relate to one record in a parent table 11 12 a a b Describe four major shortcomings of the conventional paper file structures that are being addressed by the database approach 4mks Unnecessary duplication of data Boredo
122. ty of the data e a reference to where it is to be used e Accuracy required Availability of space Appropriateness of the devic Describe three win erformed by the CPU 3 mks i arri rocessing of data ii Sys ontrol it controls the sequence of operations within the computer iii It gives commands to all parts of the computer iv It controls the use of the Main Memory in storing of data amp instructions v Storage of data It provides temporary storage RAM amp permanent storage ROM Explain the functions performed by each of the following central processing unit elements 14 i ii iii iv v Control Unit 2 mks Interpreting instructions Issuing control instructions to the operating system Arithmetic and logic Unit Performs arithmetic calculations such as addition or multiplication of figures Performs logical operations amp comparison on data Performs output of logical functions variables LS ore and after processing Registers Holds data and instructions temporaril 4O processing Stores inst K4 g to be obeyed executed Holds prog ctions amp the data currently being processed lt Qi results of processing awaiting transfer to the output devices The main memory Stores data just befor fand a The system clock It determines the processing speed of the CPU In reference to ALU explain the meaning of logic operations and gi
123. ular printer can paper get stuck ii Cartridges amp Ribbons Printers iQ cific to manufacture s cartridges amp ribbons Use of clones or imitations i e rong make amp model can damage the printer mechanism iii Refilling of cartridges or re use of poor quality Ae Explain4hree hat computer technology could make office more efficient 3 mks ing of ribbons It can spoil the printer due to leakage or The easier amp faster retrieval of data i e they reduce the time and effort needed to access and retrieve information Increased accuracy of data Better presentation of data Ensure faster processing of data Ensures economic use of storage space 35 36 a Explain the steps you would follow to set up a new computer Gently and carefully connect the interface cable of each device to the correct port and to the device Connect the computer to the source of power and switch it on Observe boot up information on the screen to see whether Power On Self Test POST displays any error message A successful boot means that th Computer was properly setup b Outline three reasons why it is important to first shutgdown the computer before turning it off To avoid damaging storage devices thatMay still be in use To avoid damaging system and applicatior files To avoid loss of data and information 3 mks A computer must go thr ugh the process of booting initialization before use a Briefly
124. urces the processing is done according to the job priorities allocated and in a continuous process until all the jobs in the queue within the memory are executed This ensures that the CPU does not remain idle at any given time Manages the input and output devices The OS controls the allocation of I O devices and tries to resolve any conflicts that arise It also monitors the state of each I O device and signals Gy detected File management OS is concerned with the logical organization ways for sorting retrieving amp sharing of the It also provides a means of protectin iles amp programs against unauthorized Q of the hardware devices used for input output amp the computer amp provides access and corruption It controls the mn storage It interfaces th the system s hardware i e it provides a quick means of a the computer user and his programs gi counting The eeps records internal logs on how the computer resources e g CPU time memory peripherals are being used It also keeps a complete record of all what happens during processing usually in the form of a printed log What is an interrupt An interrupt is break from the normal sequential flow of instructions processing in a program Give three ways in which operating system are classified 3 mks The number of users they handle The number of tasks they execute concurrently Human computer interface x S Giving an exam
125. urrent page during typing b Auto complete and AutoCorrect 2mks AutoComplete helps a person to type quickly by completing automatically a word that he she has already started to type 14 15 AutoCorrect automatically replaces mistyped words with the correct ones as set by the user c Drawing and inserting a table in a document 2mks Drawing use the pen tool to draw the table Inserting table use the Table Insert table Command Explain how a paragraph can be moved from one page to another G a word processor Ky a b Select the paragraph Click Cut on the Edit menu standard t r Press CTL X Click to place the insertion eo ant to put the text Click on Edit then cho So CTRL V What is line spacing Imk The vertical iQ een two text lines in a document Explain a Q spacing specification used in Microsoft Word 3mks Ng space accommodates the largest font in a line ii 1 5 line space 1 1 2 time that of single line spacing iii Double twice that of single line spacing iv Exactly a fixed line spacing that word does not adjust v At least the minimum line spacing that is needed to fit the largest font or graphic on the line 16 17 18 vi Multiple a line spacing that is increased or decreased by a percentage that you specify 4mks Give any four text alignment features 4 mks Left alignment centre alignment Right alignment Justif
126. used to show trend DATABASES a Define a database 2mks A collection of related files organized to provide consistent and controlled access to the data items A collection of related data elements stored together under one logical structure so as to provide a consistent amp controlled access to the items A collection of information related to a particular subject or A common data pool maintained to support the BAe s taking place within the organization A b List four examples of database progra Qore today 2mks Microsoft Access Oracle a FoxPro Q Dbase ahe State the compon atabase hierarchy in ascending order 2mks O alphabets numbers and special characters Fields Facts attributes set of related characters Records Collection of fields File Collection of records a il iii iv b a Database Logical collection of files Explain three types of database models 6 marks Flat file database It holds only one set of data Relational database Related data items are stored or organized together in structures called relations or tables Each table consists of rows and colu Hierarchical database The data items are organized i al tree like structure The records are stored in multiple Ro Q r record to be related to more than one its further down the system are subordinate to the ones above Network database It allows a data other data element record 4 o express the relat
127. ustry Airports to control the movement of aircrafts their take off amp landing using radar equipment For making reservations booking purposes Storing flight information Automobile traffic control to monitor vehicle traffic in busy towns In Railways corporations to coordinate the movement of oia gons In shipping control for efficient management N cargo handling amp communication KO Offices For receiving amp sending of informatio ing computers in banking 3 mks e mails fax etc Production of documents Keeping of records Speed and sy Q information Eas pdate records Requires less space for storage Improves data security and privacy 20 21 a Define the term computer laboratory 2 mks A computer laboratory is a room that has been specially prepared to facilitate installation of computers and provide a safe conducive environment for teaching amp learning of Computer studies b Give two factors to be considered when preparing a computer laboratory 2 mks Security of computers Reliability of the source of power LS A Number of computers to be installed and the a available The maximum number of users that the accommodate List down three safety precautions Id observe when entering a computer LN 3 mks puters to dust laboratory Avoid smoking or exposing Avoid carrying rinks beverages to the computer room Avoid unn Ovements
128. ut amp to be changed at will The contents in RAM are user defined i e the user dictates ey to be contained in the RAM LS O Its contents are temporary A It is a volatile memory Forms the major proportion of main st b Name the two types of uQr their differences 3 mks i ii Static RAM Q A static uA etain its data content as long as power is provided to the memory ips 1 es not need to be re written periodically Dyn RAM Dynamic RAM can only hold its content for a short while even when power is on Therefore in order to maintain its content data a DRAM must undergo the refreshing process i e it must be re written continually Static RAM is much faster than Dynamic RAM SRAM chips are physically large amp much more expensive than DRAM chips 32 i 33 Dynamic RAM has a much higher packing density than SRAM i e a DRAM chip is able to store more information than a SRAM chip of the same size The diagram below shows as example of a secondary S X Vv Identify the name of the devices Flash Disk QS ii List down two Q s of this device over a floppy disk in storage 2 mks Smaller in sa Q storage capacity compared to a floppy disk Flas a floppy disk hence easily portable s are more reliable than floppy disks a List any four examples of optical storage devices Compact Disk Read Only Memory CD ROM Compact Disk Recordable CD R
129. ve an example of this processing operation 15 16 Logic operation is the ability to compare two quantities or numbers to determine which is greater than less than equal to or not equal to the other It also involves the testing for existing of a condition encountered during the processing of an application amp altering the sequence of instructions accordingly Give four types of registers found in the CPU 7 Accumulator Instruction LS Address register My Storage register a Name the basic unit used to speed of a computer 1 mk Hertz Hz b A computer processor speed is measured in Hertz What fraction of a second is the Q S 1x 10 1 000 000 000 seconds following ii 1 Microsecond 1 1 1x 10 1 000 000 seconds 17 18 a What is a computer bus 1 mk A communication path medium within the computer that connects the basic computer components It allows different elements or sections of the computer to communicate with each other A parallel collection of conditions that carry data amp control signals from one element to mS b State the functions of each of the following c S 3 mks another Data bus carries data from the processor to Aune the write operations and from memory to the processor during the read Control bus it carries ing amp control signals necessary to coordinate the activities of the entire AG
130. very inconveniencing or the organization will incur huge losses in case the new system fails or fac s problems The users may not have gained enough confidence to run the new system The weaknesses Ofthe old System may not be corrected amp may still be transferred to the new system Loss of jObsifor the workers whose departments are affected If the n Wasystem fails data recovery may be impossible iii Mention any two advantages of running both the manual system ad the computerized system simultaneously 2mks O If the outputs from the two systems are similar confidence in the ICT systems Users have time to familiarize themselves with the ICT systems It is reliable because it enables thorough testing Weaknesses in either of the systems are corrected NETWORKING amp DATA COMMUNICATION 1 Define the following terms 2mks i Computer network 2mks e A collection 2 or more computers connected together using tran mission media e g telephone cables or Satellites for the purpose of communicationand sharing of resources ii Data transmission 2mks e Passing information from one terminal to another aa Computer network through telecommunication channels b Differentiate between a modern anda naultiplexer 2mks e A Multiplexer enables sending of multiple data signals over the same medium either simultaneously or at diff rent times e A Modern converts a digital signal to analogue form so that it can
131. vices that understa Devices designed using binary logic ar ore reliable amp consume less energy Distinguish between Le Octal number systems and give an example of each 2mks Binary base 2 m has just two states usually called ON and OFF or 0 and 1 Oc ase 8 system has eight different characters I e 01234567 Perform the following computer arithmetic In each case show how you arrive at your answer a Convert the following Decimal numbers to their Binary equivalent i 2 45 Rem 2 22 1 2 11 0 2 5 1 2 2 1 2 1 0 1 1 ii NY ee 4510 2mks S S S Imk 2 4 Rem 2 2 0 2 1 0 0 115 0 75 x2 1 50 gt 1 0 50 x 2 1 00 gt 1 100 100 112 b Convert 77 to Binary Q WO Step 1 Convert the octal number given to deci 7x8 7x8 56 7 6310 lt number to binary Step 2 Convert the res i 111111 c Use binary addition to solve the following 410 310 2mks Step 1 Convert the decimal numbers to binary 2 4 Rem 2 2 0 2 1 0 1 1 419 100 LSS O Step 2 Add binary notations A 1002 1l 111 111 lt S er 4 d Convert 10100000001111111 to its Hexadecimal equivalent 2mks 2 23272120 23272120 TOEO O N 1 0100 0000 0111 1111
132. ving your work copied on a piece of paper as output Saving Storing a file document permanently in the computer s secondary memory e g hard disk so as to be used in the future Italicizing text making the text saint forward Header It is a standard text or information such as pa D chapter titles etc that appears above the top margin of e a document or in a section Footer It is a standard text or information O elow the bottom margin of every page in a document a What is document formatting 1mk Q o enhance the appearance of a document Give any ent formatting features of a word processor 5mks Font colouring Applying vario Text alignment Font type Setting tabs Underlining Italicizing Font size c Differentiate between superscript and Superscript is text formatted to be at the bottom of a line Superscript is text formatted to be at the top of a line Subscript is text formatted to be S gt the distance that text starts ona at the bottom of a line 12 What are page margins Non printing but visible text limiting border page away from the edge of the page a 13 Differentiate between a A Hard page break a page break 2mks A hard page br inserted on a page even before the end of the page e g by pressing C R or setting a manual page break ra Q break the text cursor moves or creates a new page automatically when at th of the c
133. windows operating system 3 mks Method 1 Inan explorer window click the file folder you want to rename Click on file choose rename Type the new name then press enter Method 2 amp Inan explorer window right click the file meee Choose Rename from the shortcut menu that a Type the new name then press Enter 16 a What is a dialog box a Window that appears tempo to request or supply information It contains options settings one must cid thon a task b List five mS may be found in a dialog box Te box you can type data in List box a box that contains a list of options one of which is selected Checkbox a small square box that can be selected or cleared It appears with an option that you can turn on or off When the checkbox is selected a selected a checkbox WJ or Exl appears in the box 17 Radio button a round button that can either be blank or can contain a dot If the button contains a dot it is selected Pull down menu A box with a downward pointing triangular button at its right end v When the triangular button is clicked it displays a menu Command button A button that can click to carry out or cancel the selected action E g the OK or cancel button a Define folder directive tree amp Directory tree is the hierarchical arrangement of mae GD from the root downwards A b Give two examples of root directories yo Gow
134. would be used For people with special needs or disabilities e g the handicapped especially those with impaired hands 10 Emergency situations Where faster data input is required In language translator or programs Voice tags for voice dialing In automated materials handling e g in airports a good handlers give spoken commands that direct the luggage to the appropriate conveyor belt For house office or car security where voice activated locks Cy access control In voice activated toys and games LS a In electronic funds transfer A Name two examples of scanning data capt ices used at point of scale terminals in supermarkets Q Barcode reader QS Light pen Cash KO a What are Qon documents These are ents produced as output and which can be re used as input by the computer b Name any two data capture techniques that make use of turnaround documents 2 mks Optical character recognition OCR Optical Mark Recognition OMR Magnetic Ink Character Recognition MICR 11 12 13 Optical Bar Recognition OBR Magnetic Stripe Recognition List five factors one would consider when selecting a data input device 4 mks The needs of the user Type of data to be input Volume of data to be entered amp Input speed LS Cost i e the initial cost of the input device amp SN the device on a day to day basis Availability amp reliabili
135. y are used to define the printable area occupy the space in the lines that follow d Kerning and tracking 2mks Tracking refers to changing the visual denseness or openness of characters in aline while Kerning is fixing particular pairs of letters that are too close or too far apart from each other e Fill and stroke A stroke refers to a line style while a fill refers to applying background pattern such as shading to a graphical object a What is layering as used in DTP LS 1 mk Layering is the placing of text or objects on top wO b Why is layering very useful in a desktop Ls Imk It may be used to create watermarks What commands are used in place of O d landscape page orientation in PageMaker Q 1mk i _ Portrait tall ii Landscape Le Give three KO that are used to transform an object 3mks Ww i R i Skewing ii Reflecting a what is text wrap 1mk Text wrap is controlling the flow of text over or around a graphical object b Give three ways you can wrap text on an object 3mks 8 Make the text jump the object to the next page or column Allow to text to jump over the object and continue on the same page Create a rectangular text wrap around all the sides of the object Define the term object grouping 2mks This refers to joining objects in order to manipulate them as one object Q QS ae V INTERNET amp E MAIL The first computer Network was set up by ARPA in the
136. zed or undesired goals stch as cost can be minimized e They enabled printing of entire worksheets portions of a worksheet or several worksheets within the shortest time possible e Have the ability to summarize data using Consolidation and Pivot tables Define the following terms as used in a worksheet 3mks i Columns These are the fields that make up the worksheet of a spreadsheet and are identified by letters They run vertically from top downwards ii Rows These are the records that form a worksheet and are identifies a They run horizontally from left to right LS gt iii Cell of A box formed when a row amp a colt K X in a worksheet where the data is entered QS spreadsheets 4mks n i Automatic recalcula This is whereby eetronic spreadsheet will adjust the result of a formula automatica e values are changed so that they correspond with the different lt gt ii What if analysis Explain the following concep What if analysis is a feature in spreadsheets that is used to find out the effect of changing certain values in a worksheet on the other cells It involves changing the values of one of the arguments in a formula in order to see the difference the change would make on the result of the calculation iii Sheet tabs These are names of the worksheets that appear at the bottom of the worksheet window They enable the user to move from one worksheet to another iv Worksheet A

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