Data reprentation Topic 1

Question 1

Define bit

Answer 1

basic computing element that is either 0 or 1

Question 2

Defnie overflow error

Answer 2

the result of a calculation producing a value too large for the computer’s allocated word size

Question 3

logical shift

Answer 3

shifting bits left or right in a register
-any out of register are replaced with 0

Question 4

two’s complement

Answer 4

method of representing negative numbers in binary

Question 4

What is most significant bit

Answer 4

left most bit

Question 5

ASCII code

Answer 5

character set for all the characters on a standard keyboard and control codes
(American standard code for Information Interchange)

Question 6

character set

Answer 6

list of characters defined by the computer hardware and software
-so computers can understand human characters

Question 7

Unicode

Answer 7

character set which represents all the languages of the world, including the ASCII code

Question 8

Sampling resolution

Answer 8

number of bits used to represent sound amplitude in digital sound recording
-aka bit depth

Question 9

bit depth

Answer 9

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

Question 10

color depth

Answer 10

number of bits used to represent the colors of a pixel

Question 11

sampling rate

Answer 11

number of sound samples taken per second in a digial sound recording

Question 12

bitmap image

Answer 12

image made up of pixels

Question 13

pixel

Answer 13

smallest element used to make up an image on a display

Question 14

image resolution

Answer 14

number of pixels that make up an image

Question 15

pixelated image

Answer 15

result of zooming into a bitmap image

Question 16

pixel density

Answer 16

number of pixels per square inch

Question 17

compression

Answer 17

reduction of the size of a file by removing repeated or redundant pieces of data

Question 18

audio compression

Answer 18

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

Question 19

What are the uses of the binary system

Answer 19

base of all computing systems

Question 20

Why is the binary system used in all computing systems [3]

Answer 20

-it only consists of two values: 0 and 1
-computers can only take inputs of on and off
-binary systems can represent the computers

Question 21

What are the uses of the hexadecimal system [4]

Answer 21

-error codes
-MAC addresses (unique number per device)
-IPv6 addresses (internet protocol address)
-HTML color codes

Question 22

Why is the hexadecimal system used [3]

Answer 22

to shorten long binary numbers
-to be interpreted by humans
-for storage
-for transfer of data

Question 23

What are the uses of the octal system [2]

Answer 23

to shorten long binary numbers
-similar to hexadecimal
-used to represent data with smaller bits

Question 24

benefits of using larger sampling resolution [3]

Answer 24

-larger dynamic range
-better sound quality
-less sound distortion

Question 25

describe a vector image

Answer 25

-consists of shapes, curves, lines, texts
-has intructions where to place the components

Question 26

Advantages of bitmap images [2]

Answer 26

-high detail (color range, gradient)
-can easily be compressed

Question 27

Advantages of vector images [2]

Answer 27

-scalability without losing quality
-typically smaller file size

Question 28

What is perceptual music shaping? [2]

Answer 28

-removing frequencies out of human hearing range
-removing softer sound if two sounds are played at the same time

Question 29

examples of lossy compression [3]

Answer 29

MP3
MP4
JPEG

Question 30

example of lossless compression

Answer 30

RLE

Question 31

How does RLE work? [2]

Answer 31

reduces identical/repeating data into two numbers
-number of identical data
-code of the data item