Data Representation Flashcards
What is a bit?
The smallest measure of data.
How many bits are in a nibble?
4
How many bits are in a byte?
8
How many bytes are in a kilobyte?
1000
How many kilobytes are in a megabyte?
1000
How many megabytes are in a gigabyte?
1000
What is binary?
A number system which uses only two numbers: 1 and 0. It is what all computers use.
Binary increases in what power?
Power of 2 (1, 2, 4, 8, 16, 32, 64 and 128)
In binary, what results from 0+0?
0+0=0
In binary, what results from 1+0?
1+0=1
In binary, what results from 1+1?
1+1=10
What direction is the binary shifted when multiplying?
Left
What direction is the binary shifted when dividing?
Right
How many digits can Hexadecimal use?
16 (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F)
How do you convert binary to Hex?
Split the binary code into nibbles. Find out the numerical value of each nibble. If it is over 9, it will be a letter from A-F in alphabetical order.
How do you convert Hex to Denary?
Multiply each digit by 16 and add the results
What is a character?
A number, letter or symbol.
What are the two main character sets?
ASCII and Unicode
What does ASCII stand for?
American Standard Code for Information Interchange
What language is ASCII?
English
How many bits are used per character in ASCII?
7 bits
How many different characters are in ASCII?
128
What is Unicode?
A character set containing international characters.
How do you work out the size of a text file?
Bits per character x number of characters
What are bitmap images made of?
Pixels
What are pixels?
Tiny dots that images are made of.
How is the colour of each pixel represented?
Binary code
How many bits per pixel do black and white images need?
1 bit
How many colours can 2 bit images be made of?
4 colours - 00, 01, 10, 11
How does increasing the amount of bits per pixel affect an image?
Increases the range of colours
What is bits per pixel known as?
Colour depth
How do you work out the range of colours based on colour depth?
2^n (n = number of bits per pixel)
What is image resolution?
Number of pixels in an image
How does resolution affect image quality?
The higher the resolution, the more pixels, the higher the quality
How do you work out the file size (in bits) of an image?
File size = image resolution x colour depth
What is metadata?
Data about data
What sort of information does metadata include?
File format, colour depth, resolution, height and width
What are vector images?
Images made of blocks of colour, stored as maths equations
What does a microphone record sound as?
An analogue signal
What are analogue signals pieces of?
Continually changing data
