Data representation Flashcards
What base is decimal
base 10
What base is binary
base 2
What base is hexidecimal
base 16
Why is hexidecimal often used in computing
because large numbers can be represented in less characters
how many bits are in a byte
8
How many bytes are in a kilobyte
1024
How many kilobytes in a megabyte
1024
How many megabytes in a gigabtye
1024
How many gigabytes in a megabyte
1024
How is bits represented
b
How is bytes represented
B
How is kilobytes represented
kB
How is megabytes represented
MB
How is gigabytes represented
GB
What happens when you shift a binary number to the left 1
The binary number is timesed by 2
What happens when you shift a binary number to the right 1
divided by 2
What is binary shifts used for
To times or divide by the powers of 2
How manys bits are in an ASCII character
7 bits
How manys bits are in an Uncicode character
16 bit
How is Unicode and ASCII ordered
They are ordered sytematically alphabeitcally
e.g A=65 B=66
How many characters can be represented by ASCII
128
What is the advantage of ASCII
- It uses a low amount of data because it only requires 7 bits of data to hold a character
What is the disadvantage of ASCII
- As it only stores 128 characters it cannot be used by different languages which use special characters
How many characters are stores in unicode
65,536
What types of characters can unicode represent
Letters(from all different languages)
Mathmatical symobls
Emojis
What is the advantage of Unicode
It can represent lots of characters (65408 more than ASCII)
What is the disadvantage of unicode
It takes up a lot of space as it uses 2 bytes to represent one character
How much does unicode and ASCII overlap
The first 127 characters of Unicode are the ASCII characters
What is amplitude
- the height of a wave
- how loud a sound is
What happens when you increace the amplitude of a sound
The volume increaces
What is frequency
storing sound
-The distance between waves
- The number of waves that occour in time period
What happens when you increace the frequency of a sound wave
The sounds pitch becomes lower
What is a sound produced naturally called
analogue
What part of a computer converts analogue to digital sound
analogue to digital converter
(adc)
What is a digital sound
A sound that is produced and stored on a computer (non natural)
What is sampling
measuring the amplitude of a sound wave at specific time intervals
What is sample rate
the number of samples taken per seconds
What is sample rate measured in
hertz
What is sample resolution
the number of bits used to store a sample of amplitude
What is the equation for file size of sound
file size = sampling rate x resolution x time in seconds
What is the equation for file size of images in bytes
Size = (width x height x colourdepth in bits)/8
in bytes
What is pixel short for
Picture element
What is a Pixel
A single point on an image
What is colour depth
The number of bits used to represent each pixel
