Computer Studies Paper 1 Questions and Answers - Cekenas Mock Exams 2022

QUESTIONS

SECTION A (40 MARKS)
Answer all questions

1. In a computer class a teacher taught on removable storage media. State three precautions of preventing data loss in such media that the teacher may have mentioned. (3 marks)
2. What is the function of an antistatic wrist member? (1 mark)
3. Classify the following software’s according to purpose. (4 marks)
   

   Software	Classification
   1. Need for Speed Game 2. BIOS 3. Google Chrome Browser 4. Adobe InDesign 6

4. Differentiate between Sequential file organization and indexed-sequential file organization. (2 marks)
5. List four threats to a computer system. (4 marks)
6. Distinguish between relative and absolute cell references as used in spreadsheet. (2 marks)
7. List three characteristics of a soft computer system. (3 marks)
8. Briefly describe two transcription errors. (2 marks)
9.      
   1. List two advantages of secondary storage devices which make them indispensable part of a computer. (2 marks)
   2. Give two reasons why magnetic tape is not a popular secondary storage device. (2 marks)
10. Define the following as used in word processing. (2 marks)
    
    1. Word wrap.
    2. Drop Cap
    3. Orphan
    4. Widow
11. Name the two common types of system units and differentiate them. (2 marks)
12. Without proper marketing, a business cannot survive in a competitive environment hence computers are being used in a number of ways to enhance marketing. List any three ways of ensuring this is effected. (3 marks)
13. Control unit is an essential component of the CPU. Describe the functions of the control unit. (2 marks)
14. Speech recognition devices are used to capture natural sound and convert the input into digital form. State two problems related to speech recognition devices. 2 marks)
15.         
    1. Differentiate between pasteboard and master page as used in DTP (2 marks)
    2. Differentiate between graphic-based and layout based desktop publishing software. (2 marks)

SECTION B (60 MARKS)
ANSWER QUESTION 16 AND ANY OTHER THREE QUESTIONS IN THIS SECTION

16.      
    1. Define the following terms as used in programming (2 marks)
       1. Source code
       2. Object code
    2. Differentiate between Assembler and Interpreter as used in programming. (2 marks)
    3. Identify the type of programming language used in the codes below; (1 mark)
       1. 1101 1101     1011 1011
          1110 0001     1100 0111
          0010 1110     1011 0011
       2. LDA A, 20
          ADD A, 10
          STO B, A
          NOP
    4. On the Nairobi-Nakuru highway, the Kenya Police have put speed cameras at a certain point to read the time a vehicle passes a point (A) on the road and then reads the time it passes a second point (B) on the same road. (Points A and B are 200 meters apart). The speed of the vehicle is calculated using:
       Speed = 100/((time at point B-time at point A)) (Km/ hr)
       The maximum allowed speed is 100 kilometers per hour.
       500 vehicles were monitored using these cameras over a 1-hour period.
       
       1. Write a pseudo code, which: (5 marks)
          • Inputs the start time and the end time for the 500 vehicles that were monitored
          • Calculates the speed for each vehicle using the formula above.
          • Outputs the speed for each vehicle and a message if the speed exceeded 100 km/hour.
            >=100km/hr “High Speed”
            <100km/hr “Normal Speed”
       2. Draw a flow chart for the above pseudo code. (5 marks)
17.    
    1. Describe two health issues related to working with computers and give a remedy for each. (4 marks)
    2. Robots are introduced into a factory which makes car engines. Describe three ways this could affect the workers. (6 marks)
    3. List two duties performed by the following personnel (2 marks)
       1. Database administrator
       2. Computer trainer (2 marks)
       3. Web administrator (2 marks)
18.        
    1. Differentiate between a database and DBMS. (1 mark)
    2. List two advantages of using electronic database systems. (2 marks)
    3. In database system, data integrity ensures the correctness and completeness of the data in the database. Differentiate the following types of integrity constraints.
       1. Validity integrity (1 mark)
       2. Entity integrity (1 mark)
       3. Referential integrity ( 1mark)
    4. Briefly describe any three database models. (3marks)
    5.      
       1. Differentiate between error handling and interrupt handling as used in operating systems. (2 marks)
       2. State three reasons why most network technicians prefer using command line operating systems to configure networking equipment. (3 marks)
19.      
    1. Define the following terms as used in networking. (3marks)
       
       1. Network
       2. Intranet
       3. Browser
    2. The World Health Organization is global entity that deals with health issues around the world. It has computer networks linking its regional and continental offices using internet. State two importance of the internet to such organization. (2 marks)
    3. Mr. Zuma, the Principal of a school wishes his school to have an internet connection in a bid to improve its service delivery. Mention four internet connectivity requirements that must be present to enable the connection. (2 marks)
    4. Explain the following as used in e-mail:
       
       • Inbox (1 mark)
       • Drafts (1 mark)
    5.    
       1. Failure of information systems is a major concern in the security of data in computing systems. State two causes of such failure. (2 marks)
       2. Explain the following computer crimes.
          
          • Fraud (1 mark)
          • Industrial espionage (1 mark)
    6. Excluding passwords, state two other security control measures used to guard against unauthorized access to computers in a network. (2 marks)
20.      
    1. Convert the 1010.0112 to decimal equivalent. ( 3 marks)
    2. Perform the following number system conversions. (3 marks)
       1. 342.258 to binary.
       2. 50310 to hexadecimal (3 marks)
    3.    
       1. Compute the binary arithmetic given below: (3 marks)
          10111 + 10001 + 101
       2. Using 8-bit notation, perform the twos complement of 2510 -1510 , leaving your answer in binary. (4 marks)

MARKING SCHEME

1. The storage media should not be exposed to excessive heat
   Not to forcefully remove the media from the drive or USB port.
   Do not bend or fold the media.
   Avoid dropping the media
   What is the function of an antistatic wrist member. (1 mrk)
2. These are gloves worn on the hands to prevent static cherge on ones hands from reaching silicon chips on the motherboard.
3. 
   

   Software	Classification
   1. Need for Speed Game 2. BIOS 3. Google Chrome Browser	Application System software Application

4. Sequential – Records are stored and accessed in a sequential order from beginning to the end of the file.
   Indexed- An index is used to enable the computer to identify individual records on a storage media.
5. Computer viruses
   Power fluctuations
   Poor Handling of storage media
   Unauthorized access
   Theft
   Sabotage
6. Relative cell reference – Cell address used in a formula that adjusts itself to reflect its position in the worksheet.
   Absolute cell reference- a cell address that keeps on referring to a special cell regardless of its position in the worksheet
7. Boundaries keep on changing
   Hard to exactly measure performance
   Goals and objectives usually conflict.
8. Misread- errors emanating from incorrect reading of the source document by the user entering wrong values.
   Transposition errors – Is as a result of misplacement of characters.
9.    
   1. High storage capacity
      Non-volatile
      Cheaper than primary storage
      Portable
   2. Its bulky
      Low storage capacity
      Its contents can only be accessed sequentially hence slow.
10.      
    1. Word wrap. – a feature that automatically moves the cursor or text to the next line when the end of the line is reached.
    2. Drop Cap – A character or a group of characters at the beginning of the paragraph that spreads in more than one line.
    3. Orphan: A paragraph-opening line that appears by itself at the bottom of a page or column, thus separated from the rest of the text.
    4. Widow: A paragraph-ending line that falls at the beginning of the following page or column, thus separated from the rest of the text.
11. Tower
    Desktop
    Desktop -the monitor is placed on top of the system unit. The tower type the monitor rests on the table
12. Electronic Commerce or e-business
    Electronic presentation
    Advertising
13. The control unit is responsible for coordinating all the activities of the C.P.U
    To coordinate these activities, the control unit uses a system clock that sends command signals
14. Recognition rate is slow – the number of words in English and the number of words which can be said at a given point (known as branching factor) mean that response rates are still relatively slow.
    Limited vocabularies – most systems are still limited to words in isolation; connected speech is much harder to get right than segmented speech. A computer may not respond to a voice command that has speech related problems like accents, Inflations and varying tones.
    Speaker variability–The speed, pitch, range, rhythm. Intonation, loudness and pronunciation of an individual can vary (especially if they a have a cold).
    Homophones – Some words e.g. see and sea, sound the same.
    Problems of speech context – A computer cannot understand different contexts and meanings of speech because it is ‘literal minded’.
    Background noise –Can upset voice input without a shielded mouthpiece on the microphone.
15.      
    1. Pasteboard: The background that lies behind your document. It is a convenient space to put things if you need to move text or images between pages. You can also place items on the pasteboard until you decide where to position them on the page. Any text or images that you place on the pasteboard won't be printed.
       Master page: A page used in designing the general layout that will be replicated in all other pages in the publication.
    2. Graphic based- They are specifically developed to edit and format graphic objects such as pictures and vector drawings.
       Layout based- Are specifically developed to create different page layout designs for text and pictures.
16.  
    1. Source code
       The program instructions entered in the program editor window that is not yet translated into machine readable form (binary language).
       Object code
       The program or source code that is already translated into machine readable form (binary language).It is produced by the assembly process (the production of a source code to machine form/binary).
    2. Assembler(s) – it is a program or language processor that translates assembly language into machine language that the computer can understand and execute.
       Interpreters – It is a translator program that translates source program one instruction at a time, completely translating and executing each instruction before it goes onto the next. Interpreters seldom produce object code but temporarily produce intermediate code which is not stored in main memory.
    3.      
       1. 1101 1101 1011 1011
          1110 0001 1100 0111
          0010 1110 1011 0011
          Machine Language
       2. LDA A, 20
          ADD A, 10
          STO B, A
          NOP Assembly Language
    4.       
       1. Start
          starttime=0
          Endtime=0
          Speed=0
          For Vehicles=1 To 500 Do
          Input Start Time
          Input Stop Time
          Speed =100/(End Time-Start Time)
          Print Speed
          If Speed >100 Then
          Print Over Speeding
          Else
          Print Normal Speed
          ENDIF
          NEXT VEHICLE
          ENDFOR
          STOP
       2.    
17.    
    1. RSI – Use ergonomic keyboards.
       Eye problems and headache. - Use LCD or antiglare screens on CRTs
       Backache - Use standard furniture.
    2. Job replacement
       Job creation
       Job displacement
    3.      
       1. Designing and developing database applications
          Setting up security measures needed to control access to data and information.
          Keeping databases up to date by adding new records, modifying or deleting unnecessary records.
       2. Training people on how to use the computer and application programs
          Developing training reference materials
          Guide learners on how to acquire knowledge
          Preparing learners for ICT exams
       3. Web administrator
          Coding websites – the most popular languages include HTML and JavaScript
          Collaborating with development teams to program websites
          Setting up tools to monitor website traffic
          Analyzing website traffic to inform design decisions
          Addressing usability issues
18.    
    1. Database – A collection of organized data.
       DBMS – Programs that help the user to enter , store, edit , retrieve and print databases.
    2. Has unlimited storage capacity.
       Has forms that provide a user friendly way of entering records
       The output is presentable.
       Editing records is easy.
       Has inbuilt queries that can help the user extract records that meets the conditions he specifies.
    3. Validity integrity (1 mrk)
       Ensures that the data entered is correct
       Entity integrity (1 mrk)
       Ensures there is no duplicate records within the table and that the field that identifies the record is unique.
       Referential integrity ( 1mrk)
       Is database concept that ensures relationships between tables remain consistent.
    4. Network model – entities form network of objects
       Flat file model – keeps one set of data
       Relational model – uses tables /relations
       Hierarchical model- data items arranged in tree form
    5.    
       1. Error handling .
          The OS has many ways of reporting to the user of any errors that occur during program execution. It does this by monitoring the status of the computer system & performing error checks on both hardware and software.
          When the user makes an error, the OS through the Kernel determines the cause of the error, and prints diagnostic messages on the screen suggesting appropriate routines of how the error can be corrected.
          In case of a fatal error that cannot be corrected, the program will be suspended permanently. E.g., the user program will prematurely terminate when it encounters an illegal operation, such as, dividing a no. by 0 or if it attempts to read a data file that had not been opened.
          Interrupt handling
          An Interrupt is a break from the normal sequential processing of instructions in a program.
          Each hardware device communicates to the processor using a special number called the Interrupt Request number (IRQ). Therefore, when an interrupt occurs, control is passed to the Kernel, which determines the cause of the interrupt. The processor stops executing the current program to wait for the corrective response of the user. Control is returned to the program that was interrupted once corrective action has been taken.   
       2. A CLI can be a lot faster and efficient than any other type of interface.
          It is secure since the expert only knows the commands.
          A CLI requires less memory to use in comparison to other interfaces.
          A CLI doesn't require high graphics, hence a low-resolution monitor can be used.
          A CLI does not require Windows to run
19.       
    1.       
       1. Network
          A collection 2 or more computers connected together using transmission media (e.g., telephone cables, or Satellites) for the purpose of communication and sharing of resources.
       2. Intranet
          Internal corporate network that uses the infrastructure of the Internet and the World Wide Web.
       3. Browser
          A browser (short for web browser) is a computer program/software that accesses webpages and displays them on the computer screen. It is the basic software that is needed to find, retrieve, view and send information over the internet.
    2. Communication with other organizations, with your members, with your staff, with your supporters and donors through e-mails, messenger, web pages, mail lists, web site message boards. The Internet greatly offers rapid communication on a global scale. It even delivers an integrated multimedia entertainment that any other mass medium cannot offer.
       Publishing your message to the world using online books, journals, press releases, workshops, conferences, lectures. Websites with conference proceedings, PDF (Portable Document Format) files of your publications, blogs, newsfeeds e.t.c. support publishing.
       Customer support - the people you are helping through your organization. It can help them when you aren't there: email, messenger, web pages, mail lists, and web site message boards. With video-conferencing, podcasting and other great web tools, you can even have workshops and classes online.
       Research on news, issues, papers and literature relevant to your cause. Use of search engines to find materials world-wide, mail lists e.t.c.
       Leisure activities – e.g. online games, videos or music.
       A place to do business and many other commercial activities. E.g. e-bay, amazon.com, e.t.c.
    3. Transmission/Telecommunication/Network media
       Data Terminal Equipments - A TCP/IP enabled computer with a web browser.
       An account with an Internet Service Provider (ISP).
       Networking equipment such as a modem, router or switch to connect the computer transmission media.
    4. Inbox: Stores incoming mails (1 mark)
       Drafts: Stores a saved copy of e-mails (usually composed but unsent) for later use. (1 mark)
    5.        
       1. Hardware failure due to improper use.
          Unstable power supply as a result of brownout or blackout and vandalism.
          Network breakdown
          Natural disaster
          Program failure/crash
       2. Fraud (1 mark)
          Fraud is the use of computers to conceal information or cheat other people with the intention of gaining money or information.
          Industrial espionage (1 mark)
          Involves spying on a competitor to get or steal information that can be used to finish the competitor or for commercial gain. The main aim of espionage is to get ideas on how to counter by developing similar approach or sabotage.
    6. Audit trails
       Firewalls
       Proxy servers
       Log files/security monitors
       Encryption
       User access levels/Multilevel access
       Biometric security
20.    
    1. 
       

       23	22	21	20		2-1	2-2	2-3
       1	0	1	0	.	0	1	1
       8	0	2	0		0.5	0.25	0.125

       8+0+2+0      0+0.25+0.125      Ans = 10.37510
    2.    
       1. 342.25₈ to binary.
          

          3	4	2	.	2	5
          011	100	010		010	101
          011	100	010		010	101

          Ans = 11100010.0101012
       2. 503₁₀ to hexadecimal (3 marks)
          

          	Divide	Result	INT	DEC PART *16	Hex
          Ignore decimal parts	503/16	31.4375	31	0.4375 x 16 =7	7=7
          	31/7	1.9375	1	0.9375 x 16 =15	15=F
          	1/16	0.0625	0	0.0625 x 16 =1	1=1

          Ans = 1F7
    3.      
       1. 10111 + 10001 + 101
          

          Carry digit ˃	1	1	1	1	1
          	1	0	1	1	1	1
          +		1	0	0	0	1
          	10	0	0	0	0	0

          
          

          Carry digit ˃		1	1	1	1	1	1,1
          	1	0	0	0	0	0	0
          -					1	0	1
          		1	1	1	0	1	1

          Ans = 111011
       2. 25 = 00011001
          15 = 00001111
          Ones complement/Bitwise NOT 15 = 11110000
          Twos complement 15 (11110000 + 1) = 11110001
          Add the binary of 25 to the twos complement of 15 i.e. 00011001 + 11110001
          

          Carry digit ˃	1	1	1				1
          	0	0	0	1	1	0	0	1
          	1	1	1	1	0	0	0	1
          	(1)0	0	0	0	1	0	1	0

          Ignore overflow bit. Ans = 00001010