Data Representation Flashcards
Name the order of size (smallest first) for storage terms
Bit, Byte, kilobyte, Megabyte, Gigabyte, Terabyte, Petabyte
State the three steps of converting negative numbers into binary.
Create positive number
Invert all 0s and 1s
Add 1 to right hand bit
What two parts of a real number does a computer store?
Mantissa and Exponent
State an advantage of using floating point representation.
Takes up less space for storing large numbers and allows real numbers to be stored
State a disadvantage of using floating point representation.
The computer must split its storage space between mantissa and exponent. This can cause rounding errors
What are the four sizes of floating point numbers defined as?
16 bit- Half precision
32 bit- Single precision
64 bit- Double precision
128 bit - Quadruple precision
What is the structure (sign, exponent and mantissa) of a SINGLE precision number
Sign - 1 bit
Exponent - 8 bits
Mantissa - 23 bits
State three advantages of using the binary system?
0s and 1s are easily represented in digital
Dropping voltage does not affect the data
Less rules of arithmetic
What increases with the number of bits allocated to the mantissa
An increased accuracy or precision
What increases with the number of bits allocated to the exponent?
An increased range
How do computers store integers?
Binary representation
How much storage does a single ASCII character take up
1 byte (8bits)
State a disadvantage of using ASCII
Representing symbols from other languages
How many characters can Unicode represent compared to ASCII?
Unicode - 65536
ASCII- 255
State two advantages of using Unicode
Can represent more symbols
Can represent more languages
What is the difference between analogue and digital?
Analogue can have values of max and min
Digital is simply made up of 1s and 0s
State 5 factors that affect file size of a video.
Movie Length Frame Rate Resolution Sound bitrate Movie Format
What two things happen when sampling depth/frequency is increased?
Quality increases/ file size increases
Name types of video formats
Flv Ogg Mov Wmc Mpg/Mp4
What is the difference between the number of colours AND bit depth in monochrome and those in True colour
Monochrome - 1 bit depth, 2 colours
True Colour - 24 bit, 16777216 colours
What happens when you increase the bit depth of an image
There is a higher colour depth
The file size increases
State advantages of vector over bitmap
Vector is resolution independent
Not blurred by resizing
Objects can be selected and edited
File size is smaller
State two disadvantages of vector graphics
Requires specific vector packages to create
Cannot represent photo realistic images
State advantages of bitmap graphics
Image can have effects applied to them
Represent photos
State disadvantages of bitmap
Large storage space
Blurred with resizing
State 5 bitmap file formats
Bmp Gif Png Tiff Jpeg
State the range of values that two’s complement could store using 8 bits
-128 to 127
Describe the difference between lossy and lossless compression
Lossless may be uncompressed, recreating the original file with all the original data
Lossy file is compressed, data is permanently lost
