1. data representation

Question 1

what is ASCII code

Answer 1

standard character set used worldwide to represent characters in a computer system.it originally only represents english language

Question 2

how many bits does ASCII code use?

Answer 2

7 bits which represents 128 different characters.

Question 3

why a computer represents
text and the use of character sets

Answer 3

Text is converted to binary to be processed by a
computer

Question 4

what is Unicode character set

Answer 4

Unicode allows for a greater range of characters
and symbols than ASCII, including different
languages and emojis

Question 5

how many bits does unicode use?

Answer 5

16 bit combination

Question 6

what waves is for real sound and computer sound

Answer 6

real sound uses analogue waves and sigital sound is made by digital waves

Question 7

what are digital wabes

Answer 7

a sequence of discrete signals desighned to give the ilusion of constantly changng siunt- a complex series of on and off instructions

Question 8

what is sampling

Answer 8

a sound to be
converted to binary, which is processed by a
computer

Question 9

what is the sample rate

Answer 9

the number of samples taken in per second

Question 10

what is the sample resolution of an image

Answer 10

The resolution of an image is the number of pixels in the width × the height of the image.

Question 11

what does the bit depth refer to?

Answer 11

refers to how many bits are used to store the colours in each pixel of the image

Question 12

what is the relation between the accuracy of the recording and the sample rate and resolution

Answer 12

The accuracy of the recording and the file size
increases as the sample rate and resolution
increase

Question 13

what is a image

Answer 13

An image is a series of pixels that are converted
to binary, which is processed by a computer

Question 14

what is the resolution of an image

Answer 14

• The resolution is the number of pixels in the
  image

Question 15

what is the colour depth of a image

Answer 15

the number of buts used to represent each colour

Question 16

what is the relationship between file size and uality with resolution

Answer 16

The file size and quality of the image increases as
the resolution and colour depth increase

Question 17

what are the ways data can be measured

Answer 17

• bit ( 1 or 0)
  – nibble( 4 bits)
  – byte ( 8 bits)
  – kibibyte (KiB) ( 1024 bytes)
  all 1024 of previous measurement in bytes
  – mebibyte (MiB)
  – gibibyte (GiB)
  – tebibyte (TiB)
  – pebibyte (PiB)
  – exbibyte (EiB)

Question 18

how to calculate the file size of an image

Answer 18

image file size= ( image width x image eight) x bit depth

Question 19

how to calculate the size of a sound file

Answer 19

sound file size = sample rate × sample resolution × length of track

Question 21

what is compression

Answer 21

compression involves applying an algorithm to a file in order to reduce the size of the file

Question 22

what are advantages of compression

Answer 22

– less bandwidth required
– less storage space required
– shorter transmission time

Question 23

what is lossless compression

Answer 23

Lossless compression reduces the file size
without permanent loss of data, e.g. run length
encoding (RLE)

Question 24

what is lossly compression

Answer 24

Lossy compression reduces the file size by
permanently removing data, e.g. reducing
resolution or colour depth, reducing sample rate
or resolution