Convert 250 000 MB to terabytes.
0.25 TB
Describe how binary is used to represent data in computers.
Computers are made up of logic circuits
Which use the electricity being on or off as representing a 1 or a 0
Convert 12310 into binary.
111 10112
Convert EA16 into decimal.
23410
How many 8-bit binary numbers are there?
28 = 256
Right-shift 110001012 by two places.
1100012
Define the term "character set".
A collection of characters
That a computer can recognise from their binary representation.
Unicode uses 32 bits per character.
James claims that Unicode can represent 4 to 5 times as many characters as 7-bit ASCII.
Explain whether or not James is correct.
James is wrong
ASCII can represent 27 = 128 characters
But Unicode could represent 232 ≈ 4.3 billion characters
In 7-bit ASCII, the character "x" is represented by the binary code
111 10002.
What binary code represents the character "r"?
111 00102
State how changing the colour depth affects the quality of an image.
Increasing the colour depth increases the quality of an image.
State how changing the sampling rate affects the quality of an audio file.
Increasing the sampling rate increases the quality of an audio file.
Give one benefit of using lossy compression instead of lossless compression.
The file size will probably be smaller.
Use RLE to encode the string abbcccddd.
(1, a) (2, b) (3, c) (3, d)
Could changing the order of the characters inside a string affect the length of the output of RLE? What about for Huffman Coding?
RLE: yes (because if you put long runs of identical characters next to each other the output will be shorter)
Huffman Coding: no (because no matter how you arrange the characters, the length of the binary code for each specific character is fixed)