MANGU HIGH SCHOOL TRIAL 2 MOCK 2021 COMP PP2 MARKING SCHEME

1. Importance of:-
2. –     RAM  – hold data that is urgently needed by the processor
3. Short term storage/ temporary storage for holding data instruction during processing
4. Hard disk – used to store large volumes of data that is not urgently required by the processor. Also for back up of os and data                                                (Correct description @ 1mk x 2  = 2mks)
5. Application areas of artificial intelligence

–     Expert system

      –     Natural language processing

      –     Robotics

      –     Artificial neural networks                                   (Each correct @ 1mk x 2 = 2mks)

• a)   Embedded object

            a separate image/ graphic/ clip that is placed into a file e.g. movie clip pasted into DTP document

             would be considered as an embedded object

• Auto flow: Facility that allows text to flow automatically from one textbox to the next when the first

text box is full                                        

• Zoom – changing the magnification of publication page either to get a closer view (zoom in) or to see more of the page at a reduced size (zoom out).                 (Correct description @ 1mk)each x 3 = 3 marks
• Ways of identifying an illegal copy of an operating system
• No license agreement as certificate of authenticity
• Prices that are extremely cheap
• No documentation manual
• When one connects to the internet for authentication, the report from the manufacturer indicates that the user may be a victim of software counterfeit.
• Frequent run time or occurrence of fatal error when using the machine.            (Each correct @1mk x 4 = 4mks)

• Source of information for the best farming practices
• Searching tool for best market for their produce
• Marketing tool
• ICT can also be used by farmers to manage complex business systems

                                                                              (any correct 3 @ 1mk x 3 = 3mks)

• Definition
• Password – Is a code that must be keyed in so as to access a file or a system
• Authentication – is the process of verifying a log on credentials of a user requesting access to a computer system or a resource.                                                      (Each correct definition @ 1mk x 2 = 2mks)
• Roles of an I.S.P
• Link user to the internet
• Host websites
• Provide customized email addresses
• Manage internet traffic
• Provide firewalls                                                     (any 3 correct @ 1mk x 3 = 3mks)
• –
• Design, develop and test websites

–     Maintain the websites

–     Upload information into the website

–     Monitor or control access to the website                   (any 2 @ 1mk each x 2= 2mks)

• Configure a computer network

–     Maintain and enforce network security measures

–     Check the user of computer network resources

–     Troubleshoot a network                                           (any 2 x@ 1mk each x 2=2mks)

• Advantages of using computer aided design
• Easy simulation and testing of models
• Duplicates of design are easy to produce
• Easier to make changes or update the original design 
• The length of time taken to draw design is reduced/ faster       (Any 3 @ 1mk x 3 = 3mks).
• –

–     Primary file/ main document

–     Secondary file/ data source

–     Merged file / letter                                                               (any 2 @ 1mk x 2 = 2mks)

1. Disadvantage of using magnetic tape

–     Wastage of space due to inter record gap (IRG)

–     Tapes are susceptible (prone) to dust, stroke and magnetic fields which distort data on the tape

–     Tapes have short life span (average of about 2 years)

–     Data stored on a tape must be read/ accessed sequentially

–     Data stored on magnetic tape ( and – disk) is not human readable e.g. if you wish to verify the accuracy of data stored on tape, a computer run would have to be made, in order to read the content on the tape and print it.                                                                                                    (Any 3 @ 1mk x 3 = 3mks).

1. Reasons why keyboard may not function correctly in reference to cabling
2. Keyboard  might not be connected through the right port
3. Keyboard might not be connected at all to the port
4. Pin(s) in the keyboard could be bent or broken
5. There could be breakage of the cable                                    (Any 3 @ 1mk x 3 = 3mks).
6. Ways in which robots can be used in the army
7. Detect bombs set up by the enemy and then detonate them
8. Spy on the activities of the enemy
9. Clear land mines any disarm bombs
10. Confuse the enemy by deploying decoys
11. Retrieve items from dangerous war zones                             (Any 3 @ 1mk x 3 = 3mks).
12. – H20 + P$18                                                                      (correct answer = 1mk)
13.  
14. Stimulation – is the modeling /imitating/mimicking/demonstrating real world situations.

                                                                                          (Correct definition – 1mk)

• Application areas of simulation
• Aviation
• Lab forecasting
• Missile launch
• Entertainment games
• Space exploration
• Vehicle accidents
• Medical training                                                                  (Any 2 correct @ 1mk x 2 = 2mks).  

      SECTION B (60 MARKS)

1.  
2. i)    = 1

      ii)   = 3

      iii) = 1                                                                               (Each correct @ 2mks x 3 = 6mks)

• pseudocode

      Start                                               marks

      S=1                                                start / stop – 1mk

      Read Y                                           initialization – 1mk

      Repeat                                            input/ output – 1mk

            Y-Y/10                                     looping – 1mk

            If Y <10 Then                           if statement -1mk

                S=S+1                                   logical sequence – 1mk

            End if

          Until Y<10                                  total = 6mks

        Print S

      Stop 

• Advantages of low –  level languages
• The CPU can easily understand low – level languages without or with little translation
• The program instructions can be executed by the processor much faster as complex instructions are already broken down into smaller simpler ones
• They have a closes control over the hardware, are highly efficient and allow direct control of each operation
• They require less memory space
• They are stable i.e. do not crash once written
• Not commonly used, hence can be used to code secret programs        (Each 3 correct @ 1mk x 3 = 3mks).

1. – a) i) 15₁₀

                               = 1111₂

                        12₁₀=1011₂        √1 mk

      Ones complement of = 1100₂ = 0011₂ √(1mk)

      Therefore:

                                       1111₂

                                    + 10112     √

      Overflow bit           (1) 1011₂

                                           1011 +

                                              + 1 (overflow bit)

                                    = 1100₂√ 1mk

      ii)   10111₂ – 1011₂

            Ones complement of 01011₂ = 10100₂√ 1mk

            Therefore

                        10111₂

                        10100

                        (1)01011                       √1mk

                        Add the overflow bit

                        01011₂ + 1₂ =01100₂      √1mk

b)    Binary positive is 0010₂                  √2mks

       Convert to base 10              √1mk

                           = + 2₁₀             √1mk

c)   Whole numbers

      10/2           = 5       R         0

      5/2             = 2       R         1      read upward. √1 mk

      2/2             =1        R         0

      ½               = 0       R         1

Fractional part

      0.375x 2    =          0.75

         .75 x 2    =          1.50     read the whole number downwards √1mk

         .5   x 2    =          1.00

                        =          0.011₂

  Combine the two

                       =           1010₂ + 0.011₂    √1mk

                       =            1010.011₂         √1mk

• Base five numbers

      0, 1, 2, 3, 4  √1mk

1. a)
2. Advantages of wireless over Fibre optic
3. No cumbersome cabling needed between sites
4. Do not require access rights on the land between the buildings
5. Wireless support un-directed signals therefore allowing more recipients
6. Allows remote access to the network to the network signals
7. Less risks of vandalism                                                              (any correct 3 @ 1mk x 3 = 3mks)
8. –     access points

–     Wireless antence

      –     Personal computer memory card international association card     (Any 2 correct @ 1mk x 2= 2mks)

b)   i)    In Ethernet topology , all computer listen to the network media and a particular computer can only send data when none of the others is sending while in token ring (topology the data to be transmitted is placed in a special packet which then goes around the network. Only the computer whose address is on the data held in the token will pick the token to read it.                                                       (Correct difference = 2mks)

      ii)   Hierarchical topology

      Advantages

–     Provide centralized control

–     Easy to add and remove notes

–     Easy to isolate faults

–     If a non- critical node falls, the network is not affected since partial communication is still possible

–     It is possible to give control in the network to the DTE’s other than server

–     Enhances data security and privacy                                                  (Any 2 correct @ 1mk x 2 = 2mks).

      Disadvantages

–     If the parent node fails, the network fails because it controls all other computers in the network

–     If the linear backbone fails, the network fails

–     Installation is expensive

–     Data moves slowly along the branches

–     It is difficult or complex to implement in a wide area network            (Any 2 correct @ 1mk x 2 = 2mks).

• Importance of the front end processor

–     They link terminals to the central/ host computers

–     They are used to control the communication information between the various work stations and the host computer

–     They handle input and output activities from various terminals

–     They relieve the main processor from excess storage and processing by handling some of the limited processing activities                                                                                   (Any 2 correct @ 1mk x 2 = 2mks).

• This is a network situation where all the connected computers are equal and each work station in the network acts both as the client to resources hosted by other computers and a server to the resources it hosts. 
• –
• –  Classification of related files will be easier

–  Retrieving central files will be easier                                             (Any 2 correct @ 1mk x 2 = 2mks).

• Time sharing mode is where the central processor serves two or more users with different processing requirement                                                                                                     (correct definition = 2mks)

      Advantages

• Better services to user since the output is fast
• User interaction is possible through terminals                                   (Any 2 correct @ 1mk x 2 = 2mks).

      Disadvantages

• The user has no control over the central computer
• The response time is slow where there are many tasks                       (Any 2 correct @ 1mk x 2 = 2mks).
• Importance  of training staff or users
• To remove the fear of change from them
• To convince the staff of the user department on the effectiveness and efficiency of the new system
• To enable the staff run the system or to show users how the system can help them perform their job better
• To enable the staff to cope with the processing tasks of the new system
• Contents of feasibility study report 
• Recommendations on whether to continue or abandon the project
• Methods used to collect data
• Benefits and limitations expected (whether cost effective)
• Technology required to develop and maintain the project
• Installation and running cost
• Time limit                                                                                       (Any 3 correct @ 1mk x 3 = 3mks).
• –
• Field values are the values assigned to the attributes i.e. actual names classes,
• The field value for each student constitutes a record
• The collection of all student records is the file.                                 (correct description each @ 1mk x 3 = 3mks)
•  Admission number – Text

      Membership number – Text                                                              (Each correct @ 1mk x 2 = 2mks)

• Membership number                                                                  (correct statement = 1mk)
• i)    Table  – for storing data

            Form – data entry, editing and viewing the records

            Query – extracting data based on some criteria, performing calculations

            Reports – creating summaries for data, performing calculations (Each correct purpose @ 1mk x 4 = 4mks)

ii)   –     Forms

      –     Queries

      –     Reports                                                                                     (Any 3 correct @ 1mk x 3 = 3mks).

• i)    55 (correct = 1mk)

      ii)   11 (correct = 1mk)