1. Hardware failure
2. Corrupted software files
3. Hacking into the system
4. Power failure

A parameter represents additional information that  a function requires to perform its task. Each parameter required by a function is specified in the function header

An argument the value supplied in the function call. When the function is called, the argument value is passed into the function parameter so that the function can perform its task

• By setting the validation rule for the input controls on the property sheet in design view
• By use of VBA to restrict user inputs for a given control on a form
• By use of queries to restrict options available for the user in a combo box or listbox
• Setting correct data types for the fields in table the design
• Enforcing referential integrity in database relationships
• Use of input mask for the controls on the property sheeet in design view

DVD - optical media which use one spiral track; red lasers are used to read and write data on the media surface; makes use of dual-layering technology to increase the storage capacity

ROM - non-volatile memory chip; contents of the chip cannot be altered; it is often used to store the start-up routines in a computer (e.g. the BIOS)

SSD/ Solid State Drive/memory (SSD)

non-volatile memory device that uses NAND flash memories (which consist of millions of transistors wired in series on single circuit boards)

Blue Ray -  optical media that uses blue laser technology to read and write data on the media surface; it uses a single 1.1 mm polycarbonate disc

• less errors on input
• requires less storage space
• validation
• quicker to input
• quicker to find

20. a) The figure shows a network design. Use it to answer the questions that follow.

NB/ The diagram dor 20 (a)  is at the bottom

b. Explain the function of each of the following in the network

I     Router                                                                                                             [2]

- connects school LAN to the Internet/identifies the best route for data transmission/forwards data packets between a computer network and the Internet

II   Firewall                                                                                                                                  [2]

Hardware/software that filters unauthorized access to or from the school’s LAN

III  File Server                                                                                                                                [2]

Provides location for shared files/disk access/resources

c. State two categories of software that must be installed in a computer so that users can use it to access the Internet.                                                                                                                                  [2]

• Network operating system
• Browser e.g. I.E, Mozila, Google (accept examples)
• System drivers
• Protocol

d) State four ways in which computers may be used to manage data in a research environment.         [4]

The guiding principle is the candidate must mention the use and the technology to score

e.g.

1. Use of databases in data manipulation (Technology is database and the use is data manipulation)

2. Use of scanner to aid in data capturing

3. Use of Internet to communicate researched work

4. Use of printers to generate reports

5. Use of databases r hard disk to store data

etc etc

e) Some computer companies have opted to use the Internet to provide shared processing resources and online application services to users. State three advantages that this approach will have on their customers.                                                                                                                                 [3]

- The guiding principle is benefit/enhancement to the customer

• Customer will not be required to have powerful processing devices
• Customers can access services from anywhere
• There will be cost reduction for the customer
• Customers can collaborate with remote users
• Customers can access services at any time of the day
• Customers can upload/backup work in the cloud/Internet

• It is a utility software that places file data in adjacent sectors to free up space for more data and reduce access time for files stored

• All processes are held in a queue 
• Processes are prioritised 
• Processes are switched On each clock cycle

• Passive matrix create images by scanning the entire screen whereas active matrix displays are made using thin-film transistors technology(TFT)
• active matrix  display has a higher resolution compared to passive matrix
• Active matrix consume more energy than passive matrix

 Control unit

• Radio waves
• Microwaves
• Infrared waves

State four threats that compromise data integrity

• Human error
• natural disaster
• data transmission errors
• software bugs

How threats to data integrity can be minimised:

• Backup data preferably on an external storage media
• control access to data by enforcing security measures
• design user interfaces that minimise chances of invalid data entry
• using error detection and correction software when transmitting data over the network
• using devices that directly capture data from the source such as bar code readers, digtal cameras, and optical character readers

• System software that analyses, configures, optimises and maintains a computer system

• Outsourcing is the practice of using third-party providers to perform services and/or create goods that would traditionally be done within the business.

• Reads the data/packet to find the recipient's address 
• Has physical connections to >=2 different networks
• Holds a routing table
• Stores information about (IP) addresses 
• Keeps packets inside a network by not forwarding them 
• Forwards data / directs/forwards/sends packets 
• Chooses the most efficient path to the next node

• Ease of installation and use
• Application software intended for use in the computer
• Processor type. Some processors do not support all operating systems

(a)State what is meant by the terms:

Parallel data transmission

• 8 bits/1 byte/multiple bits sent at a time  
• using many/multiple/8 wires/lines

Serial data transmission

• one bit sent at a time over a single wire

The organisation of files is in a hierarchy/tree structure
A node is either a folder/directory/sub-folder/sub-directory or the file itself
The top node/folder/directory/drive is the root

• camera film speed, position (end of film), distance, light
• washing machine amount of water, speed of wash/temperature/time
• fridge temperature, display panel
• air conditioning temperature, timing, display pane

• Portable
• Light
• Faster access speed
• No moving parts
• Efficient power consumption
• Durable
• Small physical size
• Large storage capacity