State advantages of batch processing
Defining blocking of text as used in word processing
Describe the purpose of the
(i) control unit
(ii) memory unit
(iii) arithmetic logic unit
in a computer.
i) To manage the execution of instructions
By running a clock
To decode instructions
(ii) To store OS
To store those parts of applications programs currently running
To store data currently in use
(iii) Part of the processor where data is processed/manipulated
All I/O must pass through here
Satellite services are used to provide broadband internet connectivity to regional and remote areas of Kenya. State one advantage and one disadvantage of using satellites for this purpose.
Advantages
Disadvantages
Explain the purpose of each of the following features of a spreadsheet chart (KCSE 2021, Q19 (a))
A data series
Data Marker
Legend
A data series
Data Marker
What precaution would you take in a computer lab if humidity falls below normal for prolonged periods due to weather changes?
Use a humidifier: Using a humidifier can help maintain a consistent level of humidity in the computer lab, which can prevent the negative effects of low humidity.
Avoid dry air: Avoid creating a dry environment in the computer lab by opening windows or using fans to increase air circulation.
Regular maintenance: Ensure that all computer components are properly maintained and cleaned to prevent damage due to static electricity.
Backup data: Regularly backup all important data to avoid data loss in case of hardware failure caused by low humidity.
Monitor humidity levels: Use a hygrometer to monitor the humidity levels in the computer lab and take corrective measures if the levels fall below a safe range.
Use anti-static materials: Use anti-static mats or wristbands when handling computer components to prevent static electricity buildup.
Describe the role of a repeater when used in a network.
a repeater will amplify a signal and resend it to overcome reduction in signal strength (attenuation) because over a distance network signals diminish in size/amplitude (are attenuated) due to characteristics of the media.
Explain how the operating system performs job/process scheduling/management
A school intends to install a computer network. Explain three challenges that the school may experience after the installation (KCSE 2021 Computer Studies Q19(b))
Network Failure - when the network becomes faulty or the network is down, users may not access network resources hence operations of an organization may be brought to a standstill
Security Issues: A computer network can be accessed thus there is an increased chance of hacking
The rapid spread of viruses: Viruses can easily spread to terminals of a computer network which may be very expensive to clear
Cultural and moral effects: adult content may be shared in a networked environment which may be of negative impact on teenagers
State three types of optical disks
Differentiate between action query and select query
An action query is used to modify, add, or delete data in a database whereas a select query is used to retrieve data from a database based on specified criteria but does not make any changes to the data.
List four input devices used to capture data by way of scanning
Optical Mark Recognition; Optical Character Recognition; Magnetic Ink Character Recognition ; Optical Bar Recognition
Giving answers as readers is also acceptable, that is, Optical Character Readers, Magnetic Ink Character Readers; Optical Mark Readers
When a new student is enrolled, a new record is added to the file immediately. The examination grades of all students are updated twice a year. Discuss the processing implications of these two requirements.
Enrolment:
- Data input on line
- Individual records validated
- Speed mismatch implications
- Indexes updated immediately
Exam grades:
- Data input twice
- Off line
- Run as a batch
- At otherwise downtime
Students are using their wireless notebooks to complete their work in a classroom. They will need to connect wirelessly to a printer to print their answers at the end of the lesson.
Describe how CSMA/CA (Carrier-sense multiple access with collision avoidance) operates in the above scenario.
State two ways of protecting computers against viruses.
Explain how an SSD stores data
Uses transistors( resistors and capacitors) . It can be implemented by the use of NAND or NOR gates. Data is stored on the chip as a charge
Distinguish between a client-server and a peer-to-peer network
What is a computer virus?
A computer virus is a program designed to damage other programs or causes irregular behaviour in a computer system.
Give one difference between a compiled program and interpreted program
State two reasons for carrying out software updates