State the factors that affect the performance of the CPU
Number of cores
The number of cores a processor has directly affects the performance of the processor. Each core can perform its own fetch-execute cycle independently of others, so different applications can be allocated to different cores. Quad-core (four-core) and even octa-core (eight-core) processors are becoming common
Cache memory
A processor’s cache is a small portion of incredibly fast memory. It has read and write speeds far higher than hard disk drives and even SSDs. The cache is used to store frequently used information and reduces time wasted in fetching the same information from main memory time and time again
Clock speed
A processor’s clock speed relates to the frequency of the pulses generated by the system clock. The higher the frequency, the more cycles of the fetch-execute cycle can be completed in the same period of time.
Word length
A word is a group of bits that is treated as a single unit by a processor. Words can be used for representing both instructions and data. The length of a word is the number of bits that are assigned to it, with higher word lengths allowing for more bits to be transferred and manipulated as a single unit.
Address bus width
The width of a bus relates to the number wires that make up the bus. Increasing the width of the address bus increases the range of addresses that it can specify, hence increasing the computer’s amount of addressable memory. Adding a single wire doubles the number of addressable memory locations
Data bus width
Increasing the width of the data bus increases the volume of data that can be transferred over the bus at any one time. A wider data bus allows the processor to fetch more data from the main memory in one cycle of the fetch-execute cycle, reducing the number of cycles required to fetch large volumes of data.
State email protocols
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
Describe two health risks associated with the increased use of computers.
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
Internet and E-mail Questions
Define the term internet 1mk
Explain the term web page 1mk
Explain the following internet address http://www.google.co.us in reference to the structure of a URL 3mks
What is the world wide web 1mk
Define the term browser 1mk
Explain the meaning of the word hyperlink 1mk
What is a search engine? 1mk
Explain the meaning of the term internet service provider 1mk
Identify three elements apart from a computer that is required for one to be connected to the internet 3mk
Define the term modem 1mk
What is a protocol? Write the following in full: TCP/IP, HTML, HTTP and FTP 5mks
What would you do if a website refused to load on the browser within the first attempt? 1mk
State three internet services 3mks
Define the term internet telephony 1mk
State three benefits of the internet in our society
There are four change-over methods used in the implementation stage of the system development life cycle (SDLC): direct change-over, phased, parallel and pilot.
Direct Change-Over
Phased
Distinguish between real-time and distributed operating systems (KCSE 2018)
Interfaces enable computer users to interact with the operating system. State three advantages of using a graphical user interface (GUI) for loading programs and files.
b) Give one benefit of each type of data transmission
Serial
The following are software classified according to the end user licence agreement. Briefly describe each of them:
open source software, freeware, shareware, and proprietary software
Open source : refers to software provided freely with its source code. The user can modify and redistribute the software.
Freeware: these are software that can be downloaded for free and distributed, buta the source code is hidden and cannot be altered.
Shareware: is software that is available for free within a given trial period, after which it must be bought.
Proprietary: software made for commercial purposes. The source code is hidden, and it can only be used after paying for a licence.
State the symptoms of a computer virus
Slow Performance: If your computer suddenly becomes significantly slower than usual, taking longer to boot up, open applications, or respond to commands, it could be a sign of a virus. Viruses can consume system resources, resulting in decreased performance.
Frequent Crashes: If your computer frequently crashes, freezes, or experiences sudden system reboots without any apparent reason, it could be due to a virus. Some viruses can interfere with system stability, leading to unexpected crashes or instability.
Unusual Pop-ups or Ads: If you start noticing an excessive number of pop-ups, advertisements, or banners appearing on your computer screen, especially when you're not browsing the internet, it might be an indication of adware or malware infection.
Unwanted Modifications: Viruses can modify system settings or configurations without your consent. If you observe changes in your default browser homepage, new toolbars appearing, unfamiliar icons on the desktop, or altered settings, it could be a sign of a virus.
Unusual Network Activity: If you notice excessive network traffic, unusual data transfers, or a sudden increase in data usage without any known reason, it could be an indication of a virus or malware actively communicating with external servers.
Missing or Modified Files: Viruses can delete, encrypt, or modify files on your computer. If you find missing files or encounter unexpected changes in file sizes, names, or extensions, it could be a result of a virus infection.
Disabled Security Software: Some viruses attempt to disable or circumvent antivirus or security software to avoid detection. If you notice that your antivirus program or firewall is deactivated, modified, or unable to update, it could be due to a virus compromising your security software.
Unexpected Email or Message Activity: Viruses can use infected computers to send spam emails or messages to contacts in your address book without your knowledge. If your friends or colleagues report receiving suspicious or unexpected emails or messages from you, it could be a sign of a virus.
Distinguish between a file and a folder
A file is a collection of related data given a unique name while a folder is named storage location on a storage media that contains related files
A family has purchased a computer system with the following specification:
Processor speed 2200 MHz
RAM 512 Megabyte
Hard disk drive 120 Gigabytes
CD ROM
DVD writer
Modem 56k
Monitor 17"
(a) The computer has been purchased for buying goods and services over the Internet. Explain how each of these items of hardware would be used for this purpose.
Hard disk drive
RAM
DVD writer
Modem
Hard disk drive
RAM
DVD writer
Modem
A school opted to use direct changeover approach when installing a new system. Explain three challenges that the school may face as a result of this approach (KCSE 2019)
State what is meant by each of the following modes of data processing
(i) Batch processing.
(ii) Real-time processing.
(iii) Online processing.
(iv) Off-line processing.
(i) Jobs collected together for processing at a later time
(ii) Output produced quickly enough to affect the next input
(iii) User has direct contact with the processor
(iv) User cannot communicate directly with the processor
Distinguish between an optical scanner and a magnetic ink scanner
Journalists are issued with laptops when they start working at a magazine publishing company. The company only uses free open-source software (FOSS).
The laptops are equipped with either an HDD or an SSD.
The journalists can access their data remotely using virtualisation or Software
as a Service (SaaS).
2.3.1 Define the term virtualisation. (1)
2.3.2 Office365 is an example of SaaS.
(a) Except for remote data access, state TWO benefits of using
SaaS. (2)
(b) Describe how the license model of SaaS works. (2)
2.1.1 Explain the concept of open source in the context of FOSS. (2)
Give ONE example of a free operating system the company could install on a laptop. (1)
2.1.3 State TWO disadvantages of using free open-source software.
(ii) The organisation has chosen wireless connectivity over wired connectivity for its new office building. There is no significant difference in the cost of installing either.
Give three reasons why the organisation might prefer wireless connectivity.
May not have space for cables to be installed
Employees and visitors can move around the building without disconnecting
Adding new users just means giving out the SSID and password
What is a source code as used in computer programming?