KCSE 2020 COMPUTER STUDIES PAPER 1

SECTION A (25MKS)

1.List four input devices used to capture data by way of scanning 2mks

• Optical Mark Reader OMR
• Magnetic Ink Character Reader
• Bar Code Reader
• Optical Character Reader

2. Explain two consequences of not restricting the use of USB flash in a school computer laboratory 4mks

• The flash dsik may introduce viruses into the computer leading software and hardware damage
• Pirated software may be transferred and installed in the computers leading to copyright infringement
• Confidential information may be copied and disclosed to unauthorised people
• Students may install unauthorised games that may hinder learning

3. Differentiate between a computer power cable and a computer interface cable 2mks

• Interface cables are used to connect computer devices and peripherals while power cables transmit power from to socket to the computer

4. Explain two computer hardware features that may be considered when selecting a laptop computer to be used when developing a KCSE computer studies project 4mks

• Interface cables are used to connect computer devices and peripherals while power cables transmit power from to socket to the computer

5. List two examples of operating systems that are not capable of supporting computer networks 4mks

• MS-DOS
• PC-DOS

6. Explain each of the following functions of an operating system

(a) Process scheduling

• OS allocates and de-allocate tasks to CPU

(b) Interrupt handling

• It identifies interrupt from critical events and passes the control to Interrupt Service Routine which handles the condition raised by the use of priority in the queue

7. Give two examples of each of the following application packages

(a) Databases; 1mk

• MS. Access
• Oracle
• PostgreSQL
• MySQL
• SQL Server
• FoxPro
• MongoDB

(b) Word processing; 1mk

• Corel WordPerfect
• Google Docs
• Lotus word pro.
• AppleWorks
• Microsoft Word.
• Work pages.
• Wordpad.

(c)Desktop publishing; 1mk

• MS Publisher
• Adobe Indesign
• Adobe Page Maker
• Corel Ventura
• QuarkXpress

8. State two ways of preventing children from accessing adult content in a computer linked to the internet 2mks

• Installing of filtering and monitoring software
• Intall remote monitoring software to monitor children activities over the internet
• Set rules on usage of internet and social media e.g in presence of parents
• Install firewall
• Install mature content filtering software
• Install browsers made for children or use parental control feature on browser to restrict site the children can visit

9. A health centre stores patient's details in a computer. State two ways of maintaining the confidentiality of the information 2mks

• Keeping the data in encrypted form
• Use passwords to deter unauthorized users
• Keeping of audit trail
• Installing intrusion detection systems
• Installing firewall

10. Convert the decimal number 9.25 base 10 to binary number equivalent 2mks

11. Explain the meaning of the term "distributed data processing" as used in computers 2mks

• Refer data processing in which data is manipulated in different processors/computers located in separate locations but are on the same network

12. The area of a triangle is obtained using a formula: area = 1/2*base*height. Draw a flowchart that captures the input from a user, computes the area of the triangle and displays the results 3mks

13. An organisation opted to connect their computers to form a network.State two ways through which the organzation may save on the cost of their operations upon implementing the network 2mks

• Telecommuting will be possible hence reduces stress due to commuting inconveniences e.g traffic jams
• Sharing of network resources and data will be possible reducing the cost of purchasing hardware or software
• Cheaper and efficient communication i.e faster communication at a lower cost
• Sharing of internet reduces cost of purchasing internet connectivity gadget for each employee

14. State three benefits that may be realized by using ICT to manage automobile traffic operations 3mks

15. State three benefits that may be realized by using ICT to manage automobile traffic operations 3mks

SECTION B

16. (a) Explain two ways that may be used to identify the existence of errors in a program 4mks

• Use of debugging utilities
• Use of test data
• Perforrming dry run/desk checking

(b) Figure 1 show a program translation model involving the use of a translater 4mks

(i) state the type of translator required for this model 4mks

• Assembler

(ii) Explain the reason for the conversion from low level source code to machine code 2mks

• The CPU can only understand and execute machine code

(c) A private college intends to offer training on computer packages to a class consisting of 25 students. Each student is required to Ksh. 2000 for this training . A discount of 14% is awarded to each student who will have paid full fee by the opening data of new term. Write a pseudocode that captures fee paid by each student, determine whether the student is eligible for the discount , compute the total fee collected and the total discount awarded 8mks

17 (a) Explain three benefits of using twisted pair cables in a local area network 2mks

• Shield twisted pair cables are less susceptible to Electromagnetic Interferences
• It is less expensive over short distances
• It is easy to implement
It is flexible and light weight

(b) Charles has linked five computers at his home using star topology 2mks

(i) Draw a diagram representation for this tolopgy 2mks

(ii) State three reasons that may have prompted him to use this topology 3mks

• There is no disruption to the network when adding or removing a component
• The communication is very fast since each computer on the network has a direct line to the server
• Failure in a node does not affect the entire network
• It is easily to detect fault in the network
• It enables central management of the network

(iii) Explain two requirements for connecting the network to the internet 3mks

• Modem - modulates and demodulates the signals
• Router- Connects the network to external networks
• ISP- provides internet to the network at a cost
• Internet Software- Internet protocol enables computers on a network to communicate

18. (a) Explain three ways through which advancement in ICT has benefited national security 6mks

• Finger print matching systems are used to detect crimination
• CCTV footages can be used to trace criminalst
• Platforms for online reporting of crime have been developed

(b) Convert the binary number 1101.011 base 2 to decimal number equivalent 3mks

(c) A teacher entered test scores in a spreadsheet in cells range C4 to C38. State the formula that should be used to: 3mks

>

(i) Compute each of the following scores:

I. mean of the scores. 1mk

• = AVERAGE(C4:C38)

II. number of scores whose value exceed 50 2mk

• =COUNTIF(C4:C38, ">50")

(ii) Display the text "PASS" if the score is greater or equal to 30 and the text "FAIL" if otherwise 3mks

19. (a)State the unit of measure for each of the following quantities in a computer:

(i) Processor speed 1mk

(ii) Memory capacity 1mk

(iii) Data transmission speed 1mk

(b) Explain three functions of a query in a database 6mks

(c) Peter created three folders named ENG, MATHS and SWAHILI in a folder named STUDIES.In the folder ENG, he created the folders LIT and LANG while in the SWAHILI folder, he created LUGHA and FASIHI

(i)Draw a directory tree structure for all the folders created 4mks

(ii)Given that the STUDIES folder is in the root directory of drive D , write the path for a file named REVISION.DOC stored in the LUGHA folder 2mks

20. (a) Explain three ways through computer components in a computer laboratory may be protected against theft 3mks

(b) Computer studies subject has become an essential components of many professions. State three benefits of computer knowledge to an engineer 3mks

(c) A school opted to provide internet to users in the school through the use of wireless technology. Explain three challenges that the school may face by using this form of technology 6mks