chapter 1 part 3

Question 1

define bit

Answer 1

refers to one binary digit

Question 2

define nibble

Answer 2

a group of 4 bits

Question 3

define byte

Answer 3

a group of 8 bits

Question 4

what character sets can be used to represent text?

Answer 4

-ASCII
-Unicode

Question 5

define character set [2]

Answer 5

-a list of all characters and symbols that can be represented by a computer system
-each character and symbol is assigned a unique value

Question 6

define ascii [2]

Answer 6

-a character set for all the characters on the standard english keyboard
-each character is represented using 8 bits (1 byte)

Question 7

define unicode [2]

Answer 7

• a character set which can represent all the languages of the world
  -each charcater is represented using up to 32 bits (4 bytes)

Question 8

diffrences between ASCII and unicode? [4]

Answer 8

-unicode has more characters than ASCII
-unicode contains more languages than ASCII
-unicode includes emojis
-text stored in unicode takes up more storage space

Question 9

why does text stored using unicode require more storage than ASCII?

Answer 9

unicode requires more bits per character than ASCII

Question 10

how is text converted to binary? [3]

Answer 10

-a character set is used
-such as unicode or ASCII
-each character has a unique binary value

Question 11

define image

Answer 11

an image is a series of pixels

Question 12

what do the file size and quality of the image depend on

Answer 12

-image resoloution
-colour depth

Question 13

define pixel

Answer 13

the smallest component of an image

Question 14

define image resolution

Answer 14

the dimensions of an image

Question 15

how is an image converted to binary? [6]

Answer 15

-each pixel represents a colour and is given a binary value to be processed by the computer
-pixels are stored in sequence in the file
-the image resoloution is set
-that is the dimensions of the image
-the colour depth is set
-that is the number of bits used to represent each coulor

Question 16

define colour depth

Answer 16

the number of bits used to represent the colour of a pixel

Question 17

what is the effect of increasing the image resoloution on an image? [3]

Answer 17

-the image will have more detail
-the image will be closer to real-life
-the file size will be increased// the file will require more storage space

Question 18

how to calculate the size of an image file

Answer 18

image resolutions (dimensions) X colour depth (bits)

Question 18

what is the effect of increasing the colour depth of an image?[5]

Answer 18

-more bits are allocated to each pixel so..
-a greater range of colours can be seen
-the image will have more detail
-the image will be closer to real life
-the file size will be increased // the file will require more storage space

Question 19

how is audio converted to binary? [8]

Answer 19

-the sound wave is sampled….
-measuring the amplitude
-each amplitude has a unique binary value
-the sampling rate is set….
-that is the number of samples taken per second
-the sampling resolution is set…
-that is the number of bits used to represent each sample
-each sample taken is converted to binary

Question 20

define sampling

Answer 20

the process of determining the amplitude of a sound wave at set time intervals

Question 21

define sampling rate

Answer 21

the number of samples taken per second

Question 22

define sampling resolution [3]

Answer 22

-the number of bits that are used to represnt each sample..
-that defines the number of different amplitudes that can be recorded …
-that determines how loud or quiet the sounds are that can be recorded

Question 23

what is the effect of increasing the sampling resolution on the audio?[4]

Answer 23

-more bits are allocated to each amplitude so….
*more accurate amplitudes (closer to the original sound)
*a wider range of amplitudes can be recorded
*the file size will be increased??the file will require more storage space

Question 24

what is the effect of increasing the sampling rate of the audio [3]

Answer 24

-more amplitudes taken per second so
*more accurate sound (closer to the og)
*the file size will be increased

Question 25

how to calculate the size of an audio file?

Answer 25

sampling rate X length of audio file X sampling resolution