1. Data representation

Question 1

Bit

Answer 1

the basic computing element that is either 0 or 1, and is formed from the words Binary digit

Question 2

Byte

Answer 2

the smallest possible unit of storage in computer technology. Consisting of 8 adjacent bianry digits or (bits), each of which consits of a 0 or a 1

Question 3

Binary number system

Answer 3

a number system based on 2 and can only use the values 0 and 1

Question 4

Hexadecimal number system

Answer 4

a number system based on the value 16 which usesdenary digits 0 to 9 and letters A to F

Question 5

Error code

Answer 5

An error message generated by the computer

Question 6

MAC adress

Answer 6

Standing for Media Access Control, this adress (given in hexadecimal) uniquely identifies a device on the internet; it takes the form: NN-NN-NN-DD-DD-DD, where NN-NN-NN is the manufacture code and DD-DD-DD is the device code

Question 7

IP adress

Answer 7

internet protocol identified as either IPv4 or IPv6; it gives a unique adress to each device connected to a network identifying their location

Question 8

HTML

Answer 8

HyperText Markup Language is used in the design of web pages and to write, for example, http(s) protocols; colours used in webpages are assigned a hexadecimal code based on red, green and blue colours

Question 9

Overflow error

Answer 9

the result of carrying a calculation that produces a result that is too large for the computer’s allocated word size (8-bit, 16-bit, 32-bit, and so on)

Question 10

Logical shift

Answer 10

an operation that shifts bits to the left or right in a register; any bits shifted out of a register (left or right) are replaced with zeros

Question 11

Two’s complement

Answer 11

a method of representing negative numbers in binary; when applied to an 8-bit system, the left most bit (most significant bit) is given the value -128

Question 12

ASCII code

Answer 12

a character set for all the characters on a standard keyboard and control codes

Question 13

Character set

Answer 13

a list of characters that have been defined by computer hardware and software. the character set is necessary so that the computer can understand human characters

Question 14

UNICODE

Answer 14

a character set which represents all the languages of the world (the first 128 characters are the same as ASCII code)

Question 15

Sampling resoultion

Answer 15

the number of bits used to represent soundmplitude in digital sound recording (also known as bit depth)

Question 16

Bit depth

Answer 16

the number of bits used to represent the smallest unit in a sound file

Question 17

Sampling rate

Answer 17

the number of sound samples taken per second in digital sound recording

Question 18

Bitmap image

Answer 18

an image made up of pixels

Question 19

Pixel

Answer 19

derived from the term ‘picture element’, this is the smallest element used to make up an image on a display

Question 20

Image resolution

Answer 20

the number of pixels in an X-Y direction of an image, for example, 4096 x 3192 pixels

Question 21

Pixelated (image)

Answer 21

this is the result of zooming into a bitmap image; on zooming out the pixel density can bediminished to such a degree that the actual pixels themselves can be seen

Question 22

Compression

Answer 22

reduction of the size of a file by removing repeated or redundant pieces of data; this can be lossy or lossless

Question 23

Bandwidth

Answer 23

the maximum rate of transfer of data across a network, measured in kilobytes per seecond (kbps) or megabytes per second (mbps)

Question 24

Lossy (file compression)

Answer 24

a file compression method in which parts of the original file cannot be recovered during the recompression process for example, JPEG, mp3

Question 25

Lossless (file compression)

Answer 25

file compression method that allows the origial file to be fully restored during the decompression process, for example, run length encoding (RLE)

Question 26

Audio compression

Answer 26

a method used to reduce the size of a sound using perceptual musci shaping

Question 27

JPG/JPEG

Answer 27

from Joint Photo Graphic Expert; a form of lossy file compression used with image files which relies on the inability of the human eye tocertain colour changes and hues

Question 28

MP3

Answer 28

a lossy file compression method used for music files

Question 29

MP4

Answer 29

a lossy file compression method used for multimedia files

Question 30

Run length encoding (RLE)

Answer 30

a lossless file compression technique used to reduce the size of text and photo files in particular