2.4 number STORAGE Flashcards
what base system is binary?
base 2 (2 possible values)
what base system is denary?
base 10 (10 possible values)
what base system is hexadecimal?
base 16 (16 possible values)
what values are in hexadecimal?
0 -> 9 as well as A B C D E and F
when does an overflow error occur?
when a binary value is too large to be stored in the bits available
what is binary shift?
multiplication and division of binary numbers
left: multiply
right: divide
what is a character set?
a table that matches together characters and binary values
which can store more characters? (ascii or unicode)
unicode
how do you remember which stores more characters?
unicode - uni = universal so all languages
why is ascii limited?
it only uses one byte therefore only 256 characters
what about unicode makes more powerful than ascii?
2 bytes: 65,536 possible characters
file size of text files?
bits per character * number of characters
bitmap images are made of
pixels
what represents the colour of each pixel?
a binary value
what happens to the quality of a bitmap image when it is scaled larger?
it is visibly decreased greatly
how do you calculate the file size of a bitmap
file size = resolution x colour depth
what is metadata?
additional data about a file
example of metadata
- height in pixels
- width in pixels
- colour depth
- resolution
- geo location
- data created
- last edited
- file type
- author details
how do we record sound?
the amplitude of the analogue sound wave is measured and recorded in binary at specific intervals
define sample rate
the number of times per second the amplitude of the sound wave is measured
when sample rate is increased, so does _____ ______
audio quality
(or file size, but try to say audio quality)
what is sample rate measured in?
kHz or Hz
digital sampling is _______ and not continuous like analogue waves
discrete*
digital sampling is discrete and not _________ like analogue waves
continuous
what is the bit depth?
the number of bits available to represent each sample
the higher the bit depth, the more bits available so therefore
higher quality / it more closely resembles an analog wave
sound file size equation
sound file size = sample rate * bit depth * duration
