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Q&A-KCSE Computer Studies Paper 1

Convert the following:

(a) the binary number \(1111 1100_2\) to hexadecimal.

(b) the denary number \(138_{10}\) to hexadecimal.

(c) the hexadecimal number \(5D_{16}\) to denary.


(a) \(F C_{16}\)

(b) \(8 A_{16}\)

(c) \(93_{10}\)

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Differentiate between bus topology and star topology of networks. What are the advantages and disadvantages of star topology over bus topology

  • Bus topology is characterised by common transmission media shared by all the connected nodes
  • Star topology is characterised by a central switching node connected directly to each of the multiple nodes in the network

Advantages of Star topology over Bus topology

  • Faster communication as compared to bus topology
  • Independent line of connection allows freedom of removing or adding nodes

Disadvantages of Star topology over Bus topology

  • Expensive as compared to the bus topology
  • Long cable length
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State four operations that may be performed on a file by an operating system

  • file deletion
  • file copying
  • file renaming
  • file retrieval
  • file closing
  • file reading
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Factors to consider when choosing DTP software. (4 marks)

  1. Availability in the market
  2. Initial and maintenance cost
  3. User friendliness
  4. Compatibility
  5. User needs

State advantages of hardcopy output

  • They are accepted as exhibits in cases of litigation
  • Can be used without a computer
  • they are difficult to change without leaving any trace
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A typical computer’s main memory consists of both volatile and non-volatile memory.

a)  i)  Explain what is meant by the term volatile memory                                                            (1mark)

  • Memory content is lost when the power is turned off

ii) What is normally stored in the non-volatile part of a computer’s main memory                       (1mark)

  • The Computer’s BIOS

b) Explain why having cache memory can improve the performance of the CPU                         (2mks)

  • Frequently used data/instructions are store in the cache; Meaning they don’t have to be fetched from the main memory;
  • Data/instructions stored in the cache memory can be accessed faster (than data/instructions stored in the main memory) MAX 2
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Distinguish between real time processing and interactive processing

  • Real-time processing is where data is processed as it is received and the output is made available immediately to influence the ongoing activity
  • Interactive processing is computer processing in which the user can modify the operations appropriately while observing results at critical steps
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Explain two computer hardware features that may be considered when selecting a laptop computer to be used in developing a KCSE computer studies project (4mks)

Multimedia Capability - A laptop with strong multimedia capabilities is essential for a computer studies project submitted on CD-RW. This ensures that the laptop can efficiently handle multimedia content, providing a seamless experience in creating and presenting project materials.

Processor Speed - Opting for a laptop with a high processor speed is crucial. This feature enables the smooth execution of multiple applications simultaneously, enhancing overall project efficiency and reducing processing delays.

Hard Disk Capacity - Consider a laptop with ample hard disk capacity, as the Microsoft Office suite used in computer projects requires significant space for the installation and storage of project files. A spacious hard drive ensures that there is sufficient room for data and applications.

Main Memory Capacity - Given that students often work with multiple programs concurrently during a project, it's important to choose a laptop with an adequate main memory size. A smaller main memory may result in performance issues, hindering the seamless operation of various software applications during project development.

 

Internet and E-mail Questions

Define the term internet      1mk

  • The global interconnection of computer networks for purpose of communication and resource sharing

Explain the term web page    1mk

  • A hypertext  page prepared to display the content on the web

Explain the following internet address http://www.google.co.us in reference to the structure of a URL    3mks

  • HTTP- hypertext transfer protocol or simply protocol
  • WWW – subdomain
  • google – the name of the computer with the web content/domain name
  • .co – top level domain for commercial organization
  • .us- a TLD extension for the country US

 

What is the world wide web                                       1mk

  •  A virtual space on the internet that allows web pages and sites to be accessed

Define the term browser                                    1mk

  •  A software that used viewing of web content

Explain the meaning of the word hyperlink     1mk

  • A text or picture that is a link to another webpage on the internet

What is a search engine?     1mk

  • Is a special program that collects and stores links to information websites allowing users to search its database for them
  • A specialized web-based application that help the user to search for specific information on the internet.

Explain the meaning of the term internet service provider            1mk

  • A company that offers internet services to end-users

Identify three elements apart from a computer that is required for one to be connected to the internet    3mk

  • Modem
  • Internet software
  • Internet service provider
  • Telecommunication lines
  • TCP/IP protocols

 

Define the term modem 1mk

  • Stands for modulator-demodulator
  • A device that enables telecommunication to use telephone lines

What is a protocol? Write the following in full: TCP/IP, HTML, HTTP and FTP           5mks

  • Protocols – are special communication rules that govern sending and receiving of messages by computers on a network
  • Html – hypertext markup language
  • Hypertext transfer protocol
  • Transmission Control Protocol
  • Internet Protocol
  • File Transfer Protocol

What would you do if a website refused to load on the browser within the first attempt?   1mk

  • Click the refresh button on the toolbar

 State three internet services                         3mks

  • Instant messaging
  • E-mails
  • E-commerce
  • Social media and networks
  • E-learning

 

Define the term internet telephony      1mk

  • Transmission of voice data over the internet

State three benefits of the internet in our society

  • Provides a platform for conducting business and marketing
  • Provides many platforms such as social media through which people can contact each other
  • Cost saving
  • Efficient communication

A company is developing a computer for use in schools.
(a) All computers have a CPU, memory and storage.
(i) Identify the type of physical storage that uses electronic circuits.

 

Solid state
 

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What is entity integrity?

  • It ensures that each row has a unique and non-null primary key
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List three types of errors that are likely to exist in a program                             (3 marks)

Syntax errors-Incorrect use of programming language

Logical errors- The program do not give the expected output

Runtime errors- Premature end of a program

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What characterises a phased implementation approach?

  • Phased means that only one part of the system is implemented at a time
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Describe two benefits of using USB connections between a computer and a device.

  • devices are automatically detected and configured when initially attached
  • Impossible to connect device incorrectly/connector only fits one way
  • has become the industry standard
  • supports multiple data transmission speeds
  • lots of support base for USB software developers
  • supported by many operating systems
  • backward compatible
  • faster transmission compared to wireless
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Many organisations provide free public access to a wireless network.
Explain three ethical, legal or data privacy issues that an organisation should be aware of when allowing this access

  • Websites any inappropriate websites ie pornography, drugs, guns,
  • terrorism etc. e.g. is it acceptable for the organisation to allow access to this
  • sort of material when you can’t control who is accessing the service?
  • Time limit amount of time, they may not want to provide indefinite access
  • or may want to charge for access after the time limit has expired.
  • Preventing file sharing and illegal sharing\use of copyrighted materials.
  • Accountability identification of users and actions on a network by
  • preventing anonymous access.
  • Prevention of illegal activities such as terrorism and fraud.
  • The responsibility to keep children safe and protected.
  • Responsibility to keep users (customers) data safe and secure.
  • Spoofing of websites, phishing. Responsibility of organisation to put some kind of protection in place, eg filtering of known fraudulent sites.
  • Recording of private messages or details if not encrypted.
  • Recording of usernames and passwords that the user may also use to access other systems.
  • Responsibility of organisation to secure their systems from possible attack.
  • Sales and marketing providing sales leads to market products.
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Explain why solid state storage is the best choice for a fitness tracker.

  • Because it will be subject to movement  and it does not use mechanical/moving parts

          OR

  • Solid state storage is smaller/more compact so better suited for a wearable device

          OR

  • Doesn’t have moving parts  because they could be disrupted during use
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Explain why a firewall improves network security.

  • It prevents unauthorised access into the network (by checking IP/MAC address/packet content);
  •  It prevents unauthorised transmissions from inside the network to external locations;
  •  It monitors network traffic;
  • It makes sure that only the right/authorised traffic is allowed;
  • It opens/closes ports as necessary;
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State advantages of star network topology

  • Easy to add nodes
  • Managed centrally
  • Fewer data collisions
  • A single node failure does not affect the rest of the network
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Identify and describe four roles of the operating system when managing the resources of a personal computer.

Manages memory (RAM) 

  • Allocates memory to programs currently executing •

Ensures programs/data do not corrupt each other: Ensures all programs and data including itself is stored in correct memory locations

Manages processes: Ensures different processes can utilise the CPU and do not interfere with each other or crash •

Allows a user to run programs : On a multi-tasking O/S ensure that all tasks appear to run simultaneously

  • Allocates time slices 
  • Scheduling of programs
  • Handles interrupt
  • Allows a user to configure hardware
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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

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