Unit 3- Fundamentals of Data Representation Flashcards
How many bits in a byte
8 bits in a byte
What is decimal 28 in binary
11100
How many number can 8 bits represent and explain calculation
2^8-1=255
What is 0101 1001 in decimal
it is 89
What is binary
binary is a system which uses base 2 consisting of only 1s and 0s to represent number and characters
What is hexadecimal
Hexadecimal is a number system which uses base 16 base letters
What is 2A in decimal
42
Advantages of using hex
Much simpler to remember hex values
.Easy to convert between hex and binary
What is ASCII
ASCII IS a type of character set that represents lots of characters but not integers
How many bytes are needed to store “Hello everyone.”?
15 bytes
Definition of image resolution
Resolution is the concentration of pixels within a a specific area
In an image,how many bits per pixel are needed for 256 colours
8 bits per pixel-8 bit colour depth
Formula for image size in bits
Width x Height x colour depth
Formula for image size in bytes
Width x Height x colour depth/8
DIfference between analogue and Digital signals
.Analogue sound is continuous
.Digital signals are discrete
Definition of Sampling rate
Number of samples taken per second in hertz
Definition of sampling resolution
The number of bits to record each measurement
Formula for sound file size in bits
sampling rate x resolution x duration
Define Lossy compression
Lossy compression removes sounds that
we can’t easily hear or that least affect
the perceived playback quality
Define Lossless compression
Lossless compression formats
are able to reduce the file size
when compressed but do not
lose any information
Advantages of compression
Download times are reduced
Data allowances go further
It is possible to transmit
video and music data
streams as fast as they
are playing
