Computing

Question 1

What is a standard file format?

Answer 1

Is one that will open and display correctly on all platforms.

Question 2

What is lossy compression?

Answer 2

Lossy compression techniques compress data with a certain amount of visual loss when restored. Audio, video and some imaging applications can tolerate loss and in many cases, it may not be noticeable to the human ear or eye.

Question 3

What is lossless compression?

Answer 3

Lossless compression is a technique that decompressed data back to its original form without any loss. All compression methods used to compress text, databases and other business data are lossless.

Question 4

Factors that affect the size of a sound file are:

Answer 4

• The length of the recording - The longer the recording the more information there is to be stored
• The sampling depth - The number of bits used to store a sound sample. The more bits used the better the sound quality, but greater the file size.
• The sampling frequency - How many times per second that a sound is sampled. The more samples per second are taken the better the quality of the sound, but greater the file size.

Question 5

What is an operating system?

Answer 5

An operating system is a large program which manages the hardware and software of the computer system.

Question 6

What are the functions of an operating system?

Answer 6

• Interpreting user commands: The computer may have a menu-drives or a command driven user interface and this is how the user can give commands.
• Memory management: Allocates programs and data files to the space available in main memory.
• Input/output.
• File Management
• Error reporting
• Resource allocation

Question 7

What is propietary software?

Answer 7

Is also known as ‘closed software’. It’s developed by companies who typically charge a license fee for the right to use their software.
(I.E: Microsoft office, Google earth, iOS, Skype)

Question 8

What is open source software?

Answer 8

Open source software is developed, marketed and distributed by a community of individuals and is available for free.

Question 9

What are some advantages of open source software?

Answer 9

• It is free to use, distribute and change. It has lower costs, and in most cases this is only a fraction of the cost of their propietary counterparts.
• It is more secure as the code is accessible to everyone. Anyone can fix bugs as they are found, and users do not have to wait for the next release. The fact that it is continuously analysed by a large community produces secure and stable code.

Question 10

What are some disadvantages to open source software?

Answer 10

• It may not always be straightforward to use. Open source operating systems like Linux cannot be learned in a day. They require effort and possibly training from your side before you are able to master them.
• There is a shortage of applications that run both on open source and propietary operating systems; therefore, switching to an open source platform involves a compatibility analysis of all the other software used that run on propietary platforms (I.E, Much of Adobe’s design software is not available on Linux)

Question 11

What is a meta tag?

Answer 11

Meta tags are used to specify page description, keywords, author of document, last modified and other metadata.

Question 12

How would you do a compression calculation?

Answer 12

Step 1) Multiply the resolution, frame rate and bits per pixel together.

Step 2) Divide by 1024 until you get the lowest number possible (That is higher than 0).

Question 13

What are some advantages of propierty software?

Answer 13

• You will be able to take advantage of the software companies customer service department for troubleshooting and setup purposes.
• Software is often very high quality as it has been developed by professional teams.

Question 14

What are some disadvantages of propierty software?

Answer 14

• You will usually have to pay for the software as the company that produced it will be trying to make a profit.
• The software will not be adaptable; you cannot change it to meet your individual needs.

Question 15

What is ‘portability’?

Answer 15

Portability is a measure of how easily an application can be transferred from one computer environment to another.

Question 16

How do you reduce the size of a graphics file?

Answer 16

By cropping the image, lowering the resolution of changing the colour depth.

Question 17

How do you reduce the size of a video file?

Answer 17

By trimming the length of the video, altering the resolution or reducing the frame rate.

Question 18

What is a database driven website?

Answer 18

A database driven website is a web page that grabs information from a database and inserts that information into the web page each time it is loaded. If the information stored in the database changes the web page connected to the database will also change accordingly (and automatically) without human intervention.

Question 19

What is client side scripting?

Answer 19

Client side scripts run on the client side of a client-server system. (I.E - On the World Wide Web, JavaScript scripts are used client-side because they are executed by your browser).

Question 20

What is a relational database?

Answer 20

A relational database is a database which contains more than one table. The tables are linked together by using primary and foreign keys.

Question 21

What are the advantages of using a relational database?

Answer 21

> Relational databases prevent unnecessary duplication of data.
Less time-consuming than a flat-file databse.

Question 22

Explain the difference between a flat database and a relational database.

Answer 22

Flat-file databases is just one table with lots of recprds. A relational database may have two or more tables with the records more organsied. (I.E In a library one table for the book, one for the library and one for the user). These tables are linked with primary and foreign keys.

Question 23

What is a primary key and what is it’s purpose in a database?

Answer 23

A primary key is a field in a table that contains a value that is unique for every record. It’s purpose is to ensure that every record is different and are used when linking tables together.

Question 24

What is a surrogate key and when are they used?

Answer 24

A surrogate key is a field in a table which has been created by the system to ensure
that a unique field exists for every record. A surrogate key is used instead of a primary
key if no existing field is suitable.

Question 25

What is a compound key and when is it used?

Answer 25

A compound key combines more than one field in order to make a unique key.
In some databases one field is not enough data to uniquely identify a record. In a pack of
cards, there are four different suits, hearts, diamonds, spades and clubs. For example,
in a pack one single primary key would not be able to identify each different card based
on the suit, or on the card value.

Question 26

What is a foreign key?

Answer 26

A foreign key is a field in a table that is the primary key of another table.

Question 27

In relational databases, what is a ‘one-to-one’ relationship. Give an example.

Answer 27

A one-to-one
relationship is when there are two tables, both having the same number of rows. One row from table 1 relates directly to one row in table 2. This could be relevant if you have two tables in a database, one for customer names and one for customer details.

Question 28

In relational databases, what is a ‘one-to-many’ relationship. Give an example.

Answer 28

In relational databases, a one-to-many relationship occurs when a parent record in one table can potentially reference several child records in another table. The important idea is that the child cannot have more than one parent record. EG | One dentist can have many patients, but many patients can only have one dentist.

Question 29

In relational databases, what is a ‘many-to-many’ relationship. Give an example.

Answer 29

The opposite of a one-to-many relationship is a many-to-many relationship, in which a child record can link back to several parent records. EG | Many pupils have many teachers and many teachers have many pupils.

Question 30

What is CSS?

Answer 30

Cascading Style Sheets allow web developers to alter the layout and appearance of their web pages.

Question 31

What are some of the advantages of CSS?

Answer 31

The advantages of CSS are:

• The layout of many documents or even an entire website can be controlled from
one style sheet, reducing the amount of code required for formatting.

• The developer gets a more precise control over layout than by using HTML tags.

• The developer can apply different layouts to different media types, screen or print
etc.

• Several different stylesheets can be used to change the look of a site according to
users’ preferences

Question 32

What is the structure of a piece of CSS code?

Answer 32

In CSS code there is a selector, a declaration and a value.
In the following code, the ‘p’ is the selector, the color and font-size are the attributes and the ‘red’ and ‘ 16px’ are the values. The code within the curly brackets ( { } ) is the declaration. After every value, there MUST be a semi-colon as shown below.

p {
color: red;
font-size: 16px;
}

Question 33

What are the three types of selectors in CSS? Give a short definition for each.

Answer 33

• Element selectors:

These directly affect an HTML tag of the same name, so they
are simply the name of the tag as a piece of text.

• ID selectors:
These start with a # symbol and will only affect an HTML tag where the ID attribute matches the text following the # symbol. They are normally only
used to affect one particular tag, so the ID should be unique to that tag.

•Class Selectors:

These start with a full-stop (.) 
and apply to HTML tags where the class attribute matches the text following the full-stop.  They are similar to ID selectors, but can apply to multiple HTML sections.

Question 34

What are the four stages in RAD?

Answer 34

The four stages in Rapid Application Development are:

1. Requirements Planning phase
2. User design phase
3. Construction phase
4. Cut over phase

Question 35

What does the requirements planning phase entail in RAD?

Answer 35

This is similar to the analysis stage but where
users, managers and IT staff discuss and agree on what they need, the project scope, its constraints and the system requirements.

Question 36

What does the user design phase entail in RAD?

Answer 36

During this phase the developers work with users to translate their requirements into prototypes of the different systems required. This is a continuous interactive process that allows users to understand, modify, and eventually approve a working model of the system that meets their needs

Question 37

What does the construction phase entail in RAD?

Answer 37

This phase is similar to the implementation and testing
stages of the waterfall model, but users continue to be involved and can still suggest changes or improvements as the software is built.

Question 38

What does the cut over phase entail in RAD?

Answer 38

In this phase, the software is installed and tested on the new system and user training and maintenance starts.

Question 39

What is RAD?

Answer 39

Rapid Application Development means that the users should be involved at all stages of the development process and that changes to the design can be made at any time throughout the life of the project. It also means that the development process is faster
and more flexible.

Question 40

What’s an example of client side scripting on a website?

Answer 40

Addition of products into a ‘basket’ when shopping. Your name on a website after inputting login details (I.E: “Welcome, Jordan.”)

Question 41

What’s an example of server side scripting on a website?

Answer 41

A bank showing you the money in your account or a website automatically logging you out after a period of inactivity.

Question 42

What is parallel processing?

Answer 42

Parallel processing is when they are two processors working simultaneously to complete tasks.

Question 43

Why can’t we just ‘speed up’ the one processor and remove the need for another processor?

Answer 43

Because of the size of the processors they would heat up too quickly due to the amount of work they’re having to complete. Eventually melting them and causing permanent damage to the processor.

Question 44

How can processor performance be bettered by using cache?

Answer 44

Cache memory is a faster kind of memory which stores copies of data from frequently used main memory locations. The processor will use various techniques to improve performance using the cache including reading ahead in a program to load the cache with instructions which are likely to be needed soon.

Question 45

What is cache memory?

Answer 45

Cache memory is a faster kind of memory which stores copies of the data from frequently used main memory locations.