Modulation refers to the process of converting a digital signal to analog signal at the transmission end while demodulation is to converting analog signal to digital signal at the receiving end

(The parent can) set criteria for the websites she is allowed to visit such as a whitelist/blacklist of websites. The firewall will examine the data/traffic incoming and outgoing from her computer. If data is sent from a website that is not allowed, it will be blocked

It has a header

• that contains the destination address
• that contains the packet number
• that contains the originator’s address

It has a payload

It has a trailer.

• They are accepted as exhibits in cases of litigation
• Can be used without a computer
• they are difficult to change without leaving any trace

State the function of each of the following keys on the computer keyboard :  (2mks)

Backspace;

• Deletes characters to the left of the cursor

Insert

• Add characters at the cursor position
• Toggles between overtype and insert modes

An organization intends to replace an existing system by carrying out the process in stages .

Name the implementation strategy ;  (1mk)

• Phased change-over

Give two reasons why the  organization is opting to use the implementation strategy  in (a) above (2mks)

• Gives employees time to learn
• Organizations can revert to the old system in case of failure
• Reduces resistance by the employee
• It is easier to find system errors as you are dealing with only one part at a time
• Accessing parts of the old system is still is possible in case of failure of the new system

State four advantages for using a graphical user interface in loading programs and files

• User friendly
• No need to know command language as commands are executed by clicking on icons
• Allows multitasking as several programs open at the same time therefore easier to switch between applications
• Selecting an item using a mouse is easier and faster than entering commands

Or any other correct response

Advantage @ 1 Mark

Total = 4 X 1 Mark

= 4 Marks

A vehicle assembly company has introduced robots to replace the human workforce.  State two effects this would have on the workforce                

• Unemployment
• Need to retrain
• No longer need to do hazardous or tedious jobs
• Employment of skilled staff who will manipulate the robots

Or any other correct response

Effect @ 1 Mark

Total = 2 X 1 Mark

= 2 Marks

(a) Phishing

• Phishing is a strategy that encourages a computer user to part with sensitive information such as bank details hence the term ‘phishing’ – i.e. fishing – trying to catch someone out. For example, a perpetrator sends a user an email that appears to be genuine, for example, pretending to be a bank or a lawyer requesting that the user verify bank account details or send money to assist in the completing of a legal case.

(b) DoS

• DoS is a means of attack on a specific user/system/website which involves overloading a target with too much network traffic resulting in system slowdown, shutdown or a violation of security.

• the computer appears to “freeze”/”hang”
• computer won’t respond
• failure of hardware (stops computer normal functioning)
• failure of software (stops computer normal functioning)

The data before encryption is known as .......plain.................. text.
To scramble the data, an encryption ......................key.........................., which is a type
of ...................key............................, is used.
The data after encryption is known as ....................cipher............................. text.
Encryption prevents the data from being ......................understood...................... by a hacker

Transcription Errors: Transcription errors involve the incorrect entry of data due to mistakes made during the copying or typing process. These errors can occur when transferring information from one source to another.

Transposition Errors: Transposition errors specifically refer to errors where the order of characters or digits is accidentally reversed or swapped. This can happen during manual data entry or when processing information.

Domain integrity - ensures that all data in  a field contain valid values

• Developing training materials
• Training computer users
• Conducting ICT examinations
• Managing the learning and examination process
• Developing guidelines for using the computer lab
• Planning the course content
•  

• Standards specify a set of rules for hardware and/or software used in network communications. Because all manufacturers must adhere to the standards when manufacturing network hardware or software, it means that all devices should be able to communicate, regardless of manufacturer.

• To detect and remove errors
• To confirm if the program produces the expected output

(a) Describe three effects this would have on the work force

• loss of jobs/unemployment
• deskilling
• need to re-train
• different jobs available/re-skilling
• no longer need to do hazardous/tedious jobs

(b) Give two advantages to the company of introducing robots

lower work force costs (no salaries to pay)

• lower environmental costs (less electricity for heating/lighting)
• higher throughput
• more consistent product
• robots don’t need breaks, holidays/work 24/7 etc.
• robots don’t take industrial action

(c) How could the robots be trained to assemble the televisions?

• tasks repeated by skilled worker and how each task is done is memorised
• tasks programmed directly into the computer/robot memor

(d) A whole batch of televisions was produced with some of the parts missing. How could this error have been avoided?

• if parts missing for a sequence, then a warning should be given and the assembly stopped
• several quality control stages to spot an error early on
• program in checks at each stage of assembly so robots can detect a fault immediately

• their small wavelength allows conveniently sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna

(a) Buffer

• temporary storage or memory which compensates for the difference speed of peripherals and the CPU

(b)batch processing

• processing doesn’t start until all data is collected
• JCL (any reference to Job Control Language)
• no need for user interaction
• processed all in one go
• done at “quiet” times
• e.g. billing, payroll, cheque processing

(c) e-commerce

• electronic commerce
• buying and selling products/services using the internet/computer networks

(d) simulation

• studying the behaviour of a system by using a model/mathematical representation
• results can be predicted
• e.g. flight (or other) simulator, modelling hazardous chemical process

(e) Email

• sending messages from one device to another using computer networks/Internet

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

Phased:
Advantages:

• only a small part of the operation affected if new system fails
•  no need to pay for two sets of wages

Disadvantages:

•  time consuming (each part needs testing fully before expanding system)

Pilot:
Advantages:

• if new system fails, only that part will be affected
• possible to gradually train staff on pilot before whole system changes over

Disadvantages:

•  time consuming (waiting to see how pilot works before rolling out to rest of the organisation)

Direct:
Advantages:

•  less likely to malfunction since fully tested
• immediate benefits/less time wasted
•  reduced costs (only one system so no need to duplicate staff)

Disadvantages:

• disastrous if the new systems does fail

Parallel:
Advantages:

•  if new system goes down, there is a backup system in place
• possible to gradually train staff/staff have time to get used to the new system

download speed :
– speed at which information/data is transferred FROM server/Internet
– speed at which information/data is transferred TO the user’s computer
upload speed :
– speed at which information/data is transferred FROM user’s computer
– speed at which information/data is transferred TO the Internet/server