Questions
Instructions to Candidates
- This Paper consists of two sections A and B.
- Answer ALL the questions in section A.
- Answer question 16 (compulsory) and any other THREE questions from section B.
SECTION A (40 Marks)
Answer all questions in this section
- For each of the following computer generations, state the technology used to control the internal operations. (2marks)
- 1st generation:
- 2nd generation:
- 3rd generation:
- 4th generation:
- State three ways in which computers have been used to fight the spread of corona virus in Kenya. (3marks
- Define two types of booting in computer. (2 marks)
- Explain the term “log on” as applied in internet (2marks)
-
- What is disk formatting? (1mark)
- State two reasons for disk formatting (2 marks)
- State a stage in system development life cycle where each of the following activities are carried out:
- identifying the technologies that may be used in a proposed system; (1 mark)
- identifying shortcomings of a system; (1 mark)
- Preparing a system for migration plan. (1 mark)
- State three reasons why an organisation may opt to develop its own software in-house rather than buy off-the-shelf software. (3 marks)
- A particular computer stores numbers in a single 8-bit word. How would it represent? 0.312510 (3marks)
- A computer technician found it necessary to disable a firewall when working on a computer system.
- What is a firewall? (1mark)
- State two reasons that may have necessitated disabling of the firewall. (2marks)
- Differentiate between absolute cell references and relative cell references as applied to spreadsheets. (2 Marks)
- Mwanzo Micro finance organization has offices in Kericho and Nairobi connected into a network. The management is convinced that someone is illegally gaining access to the data in their computers. State three ways the company can overcome this problem. (3marks)
- The following worksheet represents the number of litres of milk produced by different cows’ species at Kajiado Ranch Ltd.
s/no A B C D E 1 Month Freisian Ayshire Guernsey 2 Jan 70 80 65 3 Feb 120 62 75 4 Mar 110 65 45 5 Apr 70 45 60
The cost of each litre of milk is Kshs.30/=. This amount is typed in cell B10- Write a function that will calculate the total number of liters of Friesian in all the months. (1mark)
- Write a formula that can be typed in cell E2 and then be copied down to obtain monthly sales of milk. (1mark)
- Identify the data type in cell C1 and cell D3 (1mark)
- State three main types of looping control structures as used in programming. (3 marks)
- A school intends to install wireless media in their communication system.
- State any two types of wireless communication media. (1mark)
- Give two advantages of this mode of communication media. (2marks)
- State the functions of the following keys on the computer keyboard:
- Backspace (1 mark)
- Tab key (1 mark)
SECTION B (60 MARKS)
Answer question 16 and any other THREE questions from this section in the spaces provided
-
- What is meant by each of the following terms as used in programming. (3marks)
- Pseudocode
- Flowchart
- Dry run
- Outline two disadvantages of low level programming languages. (2marks)
- Differentiate between compilers and interpreters as used in programming. (2marks)
- trader bought a car from a manufacturer and later sold it to another person. Write a pseudocode for a program that will accept the buying price and the selling price of the car, determine whether the trader made a profit /or loss, calculate the profit/loss and display it. (4marks)
- Draw a flowchart for the above pseudocode (4marks)
- What is meant by each of the following terms as used in programming. (3marks)
-
- State three limitations of traditional filing methods (3marks)
- Below are two table structures of files in a database.
TABLE A
FIELD DATA TYPE Employee name Text Employee number Auto number DOB Date/ time Address Text
TABLE B
FIELD DATA TYPE Employee no. NUmber Date employed date/ time Department Text Salary Currency - Which of the two tables is likely to be the parent table (1mark)
- It is advisable to ‘enforce referential integrity’ when creating a relationships. What do you understand by the term referential integrity? (2marks)
- The field ‘Employee no’ in TABLE B is likely to be the foreign key. What is a foreign key? (2marks)
- Which fields in both tables is most appropriate for creating relationship? (1mark)
- What would make the relationship between the tables fail to work? (2marks)
- In databases the field properties specify finer details related to the fields and the table entries expected. State four field properties in database. (4marks)
-
- Describe any two characteristics octal number system. (2marks)
- Convert each of the following to the number system indicated:
- 111.1012 to decimal (3marks)
- 14.687510 to binary (4marks)
- Convert the number -1710 into 8-bit:
- signed magnitude representation (2marks)
- two’s complement (2marks)
- Perform the arithmetic operation.
110.112 +11.0112 (2marks)
-
- distinguish between Computer Aided Instructions (CAI) and Computer Aided Learning(CAL) (4marks)
-
- State four activities that may be carried out when disposing off an old system in an organization. (4 marks)
- State four ways of getting user specifications during system design. (4 marks)
- State any three reasons why people may resist the introduction of computers at their place of work (3 marks)
-
- State the role of each of the following data communication devices:
- repeater; (1mark)
- router. (1mark)
- Figure 3 shows a network based on the bus topology
- Identify the component labelled p (1mark)
- State the function of component labelled p (2marks)
- Students of Neema secondary school formed an environmental club with a goal of taking part in environmental conservation activities. Outline three ways in which they can use the internet to achieve this goal. (3marks)
-
- A company has three branches A, B and C where A is the headquarter. The local area network (LAN) is directly connected to LAN at B and directly to the LAN at C. Explain two benefits of having the LAN at B also directly connected to the LAN at C. (4marks)
- List three ways by which parents can protect their children from accessing inappropriate content from the internet. (3 marks)
- State the role of each of the following data communication devices:
Marking Scheme
- State the technology used in the following computer generations (2mks)
- 1st generation
- Vacuum tubes
- 2nd generation
- Transistors
- 3rd generation
- Integrated circuits (ICS)
- 4th generation
- Very large integrated circuits (VLSI)
- 1st generation
- State three ways in which computers have been used to fight the spread of corona virus in Kenya. (3marks)
- Computers have been used to sensitize people on safety measures that help in preventing spread of virus
- For printing posters
- For conducting medical research in KEMRI
- For carrying out statistics for people infected with corona virus in Kenya in Kenya and comparing it with other countries
- State and explain two types of booting in computer. (2 marks)
- Cold booting. This is a process of starting up a computer that was initially off by pressing power button on the system unit.
- Warm booting. This is a process restarting a computer that was initially on by pressing CTRL+ALT+DEL keys
- Explain the term “log on” as applied in internet (2marks)
- Process used to get access to an operating system or application, usually in a remote computer system or application, usually in a remote computer. Almost always a logon requires that the user have (1) a user ID and (2) a password
-
- What is disk formatting? (1mark)
- Disk formatting is the process of preparing a data storage device such as a hard disk drive, solid-state drive, floppy disk or USB flash drive for initial use
- State two reasons for disk formatting (2 marks)
- To prepare a new disk so that files can be stored on it
- To create sectors & tracks for the storage of data
- To create/ prepare a new root directory and 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 the effective storage capacity of the disk, i.e. formatting enables the user to know how much data the disk can hold.
- It can also check for bad sectors on the new disk.
- What is disk formatting? (1mark)
- State a stage in system development life cycle where each of the following activities are carried out:
- identifying the technologies that may be used in a proposed system; (1 mark)
- Accept any sub stage within system analysis e.g requirement specification, problem definition, information gathering, etc
- identifying shortcomings of a system; (1 mark)
- All stages of system development
- Preparing a system for migration plan. (1 mark)
- Implementation stage
- identifying the technologies that may be used in a proposed system; (1 mark)
- State three reasons why an organisation may opt to develop its own software in-house rather than buy off-the-shelf software (3marks)
- Customised to suit business needs of the organisation.
- It can be upgraded as needed by the organisation.
- The organisation can have a module that the competitors don’t have.
- The organisation develops only the modules needed/memory eptimization, or storage/space.
- A particular computer stores numbers in a single 8-bit word. How would it represent? 0.312510 (3marks)
- 0.3125 × 2 = 0.625
0.625 × 2 = 1.25
0.25× 2 = 0.5
0.5 × 2 = 1.0
=0.0101 = 0.010100002
- 0.3125 × 2 = 0.625
-
- What is a firewall? (1mark)
- It is a program/software that filters out unwanted data and programs/criminals/hackers/malicious persons
- State the two reasons that may have necessitated disabling of the firewall.
- testing the communication link
- when upgrading the firewall
- when there is need to install an application and the firewall is preventing the operation
- when the firewall prevents legitimate communication
- What is a firewall? (1mark)
- Differentiate between absolute and relative cell references. (2 Marks)
- Absolute cell references do not change when a formula containing the absolute references is copied from one cell to another. E.g. $A$1
- Relative cell references change automatically when a formula containing the relative references is copied from one cell to another e.g. A1
- Mwanzo Micro finance organization has offices in Kericho and Nairobi connected into a network. The management is convinced that someone is illegally gaining access to the data in their computers. State three ways the company can overcome this problem. (3marks)
- Encryption
- Firewalls
- User access level/Passwords
- Limit number of log in attempts
- Audit trail
- Log files
- The following worksheet represents the number of litres of milk produced by different cows’ species at Kajiado Ranch Ltd.
s/no A B C D E 1 Month Freisian Ayshire Guernsey 2 Jan 70 80 65 3 Feb 120 62 75 4 Mar 110 65 45 5 Apr 70 45 60
The cost of each litre of milk is Kshs.30/=. This amount is typed in cell B10- Write a function that will calculate the total number of litres of Friesian in all months (2marks)
- =SUM(B2:B5)
- Write a formulae that can be typed in cell E2 and then be copied down to obtain monthly sales of milk. (1mark)
- =(B2+C2+D2)*30 OR =$B$10*(B2+C2+D2)
- Identify the data type in cell C1 and cell D3 (1mark)
- C1 – Label
- D3 – Value @1/2 x2mark
- Write a function that will calculate the total number of litres of Friesian in all months (2marks)
- State three main types of looping control structures as used in programming. (3 marks)
- The WHILE loop
- The REPEAT …UNTIL loop
- The FOR loop
- Advantages of wireless media to the school
- The school will find it easy to add or remove nodes on the system
- In case of new building is put up, there will be no need of interfering with communication media
- Users will find it safer to move around as there are no wires around the rooms
- Students will be able to roam as they access the network
- State the functions of the following keys on the computer keyboard:
- Backspace (1 mark)
- This key deletes typed characters or words from right to left on the same line at the cursor position
- Tab key (1 mark)
- Tab key is used to move the cursor at set horizontal interval on the same line such as 0.5 inch, 10 inch etc
- Backspace (1 mark)
-
- What is meant by each of the following terms (3marks)
- Pseudocode
- Pseudocode describes module design in words using syntax like programming language. It aims at proving programmer with clear and unambiguous process specification
- Flowchart
- Diagrammatic or pictorial representation that illustrates the sequence of operations to be performed to get the solution of a problem
- Dry run
- The process of manually tracing through a program using a pen and a paper to identify any errors
- Pseudocode
- Outline two disadvantages of low level programming languages (2marks)
- Difficult and cumbersome to use and learn
- They require highly trained experts to develop and maintain programs
- Removing errors (debugging) is difficult
- Are machine dependent i.e. are not transferrable from one hardware of software platform to another
- Differentiate between compilers and interpreters as used in programming. (2marks)
- An interpreter translates the source program one statement at a time while a compiler translates the entire source code at once before execution.
- Interpreted programs are slower than compiled program
- Interpreted programs takes less memory compared to compiled program
- A trader bought a car from a manufacturer and later sold the car to another person. Design a pseudocode that will accept the buying price and the selling price of the car, determine whether the trader made a profit /or loss, calculate the profit/loss and display it. (5mks)
START
ENTER “Buying Price( Bp), Selling price (sp)”
IF Bp<Sp THEN
Profit= Sp-Bp
PRINT Profit
Else
Loss=Bp-Sp
PRINT Loss
Endif
STOP -
- What is meant by each of the following terms (3marks)
-
- STATE three limitations of traditional filing methods
- Unnecessary duplication of data
- Boredom and time wastage when searching records
- Misleading reports due to poor data entry
- Poor update of records
- Below are two table structures of files in a database.
- Which of the two tables is likely to be the parent table (1mark)
- Table A because it has employee information
- It is advisable to ‘enforce referential integrity’ when creating a relationships. What do you understand by the term referential integrity? (2marks)
- To ensure all records entered in the related table exist in the primary table
- The field ‘Employee no’ in TABLE B is likely to be the foreign key. What is a foreign key? (2marks)
- A unique field that identifies each record in the secondary table in a relationship
- Which field in both tables is most appropriate for creating relationship? (1mark)
- Employee number
- What would make the relationship between the tables fail to work? (2marks)
- The data type for the same field in two tables is not similar
- Which of the two tables is likely to be the parent table (1mark)
- In databases the field properties specify finer details related to the fields and the table entries expected. State four field properties. (4marks)
- Input mark
- Validation rule
- Required
- Indexed
- Field size
- Format
- Decimal
- Caption
- Default value
- Validation text
- STATE three limitations of traditional filing methods
-
- Characteristics of octal number system.
- each symbol is represented by 3 bits.
- The number is made of 8 symbols 0, 1, 2, ...............7;
- Maximum value of a single digit is 7 (one less than the value of the base);
- This number system uses base 8.
(Any 2 x 1)
-
- 111.1012 to decimal (3marks)
solution
111 = 1 x 22+1 x 22+ 1 x 20
= 4 + 2 + 1 = 710
1012 = 1 x 2-1 + 0 x 2-2+ 1 x2-3
= 1 x 1/2 + 0 x 1/4 + 1 x 1/8
= 0.5 + 0 + 0.125 = 0.62510
111.1012 = 7.625 - 14.687510 to binary
Solution
1410 = 11102
0.687510 x 2 = 1.375
0.375 x 2 = 0.75
0.75 x 2 = 1.5
0.5 x 2 = 10
decimal part = 0.10112
Number is 1110.110112
- 111.1012 to decimal (3marks)
-
- 1710 = 100012
(1)0010001
(1) - sign bit for negative
0010001 - binary equivalent of 17 - 1710 = 100012
1n8 bit = 000100012
ones complement (00010001)2 → 111011102
Add 1 to get 2s complement + 1
1110111002
- 1710 = 100012
- Characteristics of octal number system.
-
- State any three reasons why people may resist the introduction of computers at their place of work (3marks)
- Insecurity of replacement
- Hostility towards machines
- Computer illiteracy
- Fear of training
-
- State the role of each of the following data communication devices:
- Repeater
- A device used to re-construct data signal during data transmission to its original strength/amplify/boost/regenerate.
- Router
- It is a device used to facilitate movement of data or packets between twoor more LANS of different configuration (expansion of networks).
- Delivers a packet/data directly to destination computers.
- Interconnects different networks/provides network services.
- Repeater
-
- The component P is the terminator. 1
- Terminator in a backbone is used to prevent data signal from bouncing back/absorb signals.
- Use of internet in environmental conservation club
- Source of knowledge on environmental matters;
- Collaboration with peers from other schools or organizations;
- Dissemination of information on what the club is doing;
- Seeking for funding from sponsors. First 3 x 1) 3 marks
-
- Benefits of linking branch B and C
- Speed of communication between B and C is increased since the traffic between the two branches can be re-routed through the link BC;
- If either AC or AB is down, the three branches can still communicate;
- If the HQ systems fail, the two branches B and C can communicate using this link.
(First2x2) 4marks
- Benefits of linking branch B and C
- State the role of each of the following data communication devices:
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