CS PAST PAPER Flashcards
Identify one fundamental operations of a computer
- Retreive
- Store
- Compare
- Add
Distinguish between fundamental and compound operations of a computer
Fundamental operations requires one machine instruction cycle/do not require the processor to go through many machine instruction cycles to reach a result;
A compound operation is complex/ it is an operation that involves a number of other operations to reach a result.
For example; find the largest number in an array/ sort the array in ascending order etc.
Identify one cause of data loss
Data loss is caused due to various reasons such as:-
Malicious Activities (Hacking/Theft/Virus)
Accidental deletion
Software/Hardware/System failure
Natural Disasters
Transmission error
Bad integration/ migration of systems/data
Describe one way offsite storage can be used to prevent data loss
- Internet Backup Service could automatically backup (all important) data
files; to a remote server that could be accessed/controlled over the Internet. - copies of all important data files (backup) could be placed on two separate hardware devices;
Which are placed in two different locations - A remote server could be setup for uploading all important data files.
State the function of the control unit(CU) in the central processing unit (CPU)
It decodes the instructions and controls all the other internal components of the cpu to make it work;
Explain the purpose of cache memory
Cache memory is a memory that a microprocessor can access more quickly than it can access RAM. It is located close to the cpu itself and it stores frequently used data only until a computer is powered down.
Thus, when a processor requests data that already has an instance in cache memory; it does not need to go to the main memory or hard disk to fetch the data.
State why hexadecimal numbers are frequently used in computing
Hexadecimal numbers are used for shorter representation of data because a (modern) byte can be represented exactly by two hexadecimal digits;
Hexadecimal numbers are used for shorter representation of data because, computers store and handle binary digits, and four binary digits make one hexadecimal digit.
State the maximum number of colours that can be represented in a computer pixel?
256 x 256 x 256
256^3
=16777216
Explain why abstraction is required for the design of algorithms
Abstraction is the process of taking away or removing characteristics from something in order to reduce it to a set of essential characteristics.
In object oriented programming, abstraction is one of three central principles (along with encapsulation and inheritance);
Through the process of abstraction, a programmer hides all but the relevant data about an object in order to reduce complexity and increase efficiency.
An organisation is implementing a new computer
(a) Identify two organisational issues related to the implementation of the new system.
- Software/hardware incompatibility
- User roles/ the organisation restructure their workflow
The management considered phased conversion and direct changeover as method of implementation
Evaluate these two methods of implementation
Direct Changeover:-
Is the cheapest and quickest / the old system is completely switched for the new one.
-This is straight forward but also most risky because their is nothing to fall back on if new system fails.
- It allows the organisation to change the system when most convenient
-the employees have very less time in order to get use to the new system as the change is instantaneous;
There is a period of time when neither systems are operational.
Phased Conversion
Method where the old system is still in use but parts of the new system or modules are introduced, involves bringing a new system one step at a time.
Less risky than direct changeover; less risky that the whole system will go wrong/if something happens, it will only affect the specific part.
Takes a lot of time;
Employees have enough time for training/to get use to the new system/ are introduced to the changes in small stages.
Employees/users could ask for changes which then hold up the installation of the next phase which helps improving the system.
State one type of testing that involves users.
- User Acceptance Testing;
- Beta Testing
Identify three consequences of inadequate testing.
- Can lead to software which is not appropriate for the purpose it was intended/can lead to the system not meeting the user requirements;
- Can lead to (undiscovered) bugs in the software/errors in the system;
- Can lead to end user dissatisfaction
- Can lead to reduced (employee) productivity ;
- Can lead to decreased reliability of the organisation
Discuss the social and ethical issues related to the implementation of the new system.
Personal/professional development of all employees must be considered;
Physical safety (of all users);
Human dignity of all users;
The new system might be designed to replace some stuff;
Code of Ethics (system resources should not be used without approval)
Outline two advantages of a school using a computer network.
File sharing/resource sharing;
Instead of using a USB or disk to carry files from one computer to another, files can be shared directly by using a network/all computers in the network can share resources such as printers, scanners.
Communication;
Students/teachers can communicate with people around the world via the network;
Flexible access;
Network allows students to access files from different computers (throughout the network) (one can begin work on a project on one computer and finish up on another);
Improved network security;
If the school has its own network, it can monitor traffic network/can create a security culture (everyone who has a username and password is responsible for keeping data secure);
