Computer Science 1.0 / 5 based on 1 rating ? ComputingRepresenting dataGCSEAQA Created by: Erin_WestbourneCreated on: 12-12-22 11:46 what is a bit? a single 0 or 1 1 of 27 what is a byte? 8 bits 2 of 27 what is a kilobyte? 1000 bytes 3 of 27 what is a megabyte? 1000kB 4 of 27 what is a gigabyte? 1000 MB 5 of 27 what is a terabyte? 1000 GB 6 of 27 how do you go from decimal to hex? e.g. the number 20 20 divided by 16 = 1 the remainder == 4 so the hex number would be 14 ('one, four') 7 of 27 how do you go from hex to decimal e.g. 4B 4 x 16 = 64 B == 11 64 + 11 = 75 decimal= 75 ('seventy five') 8 of 27 how do you go from hex to binary? e.g. 3B slit the two characters: 3 B 3= 0011 in binary and B (11) = 1011 in binary 3B== 00111011 9 of 27 how so you go from binary to hex? e.g. 11100101 split into two nibbles of 4 bits 1110 0101 1110 = 14 -> E 0101 = 5 11100101= E5 in hex 10 of 27 how do you go from decimal to binary? e.g 70 convert to 8-bit binary: 128 64 32 16 8 4 2 1 11 of 27 how do you go from binary to decimal? e.g. 10101101 (8-bit) 128 64 32 16 8 4 2 1 these are values on each bit 1 0 1 0 1 1 0 1 == 173 12 of 27 hex:? binary:1001101 decimal:141 e.g. 10011101 split 1001 1101 1001 = 9 1101= 13 13 = D hex== 9D 13 of 27 hex:5F binary:? decimal:95 e.g. 5F -split- 5 F 5 = 0101 F(15) = 1111 5F = 01011111 14 of 27 hex:5D binary: 01011101 decimal:? e.g. 5D -split- 5 D 5 x 16 = 80 80 + D(13) = 93 15 of 27 binary addition: 1110 + 1100 ________ 11010 16 of 27 what are the 2 character sets? ASCII Unicode 17 of 27 how many bits are in ASCII? how many character sets does this allow? -8 bits (in extended) -128 18 of 27 how does the number of colours in an image affect the file size? an increased number of colours that are used will * increase * the filesize 19 of 27 how does the size of the image affect the file size? an *increase* number of pixels *increases* the file size 20 of 27 convert a bit into a pattern: (on paper) 1001010 1001010 1111010 1001010 1001010 HI 21 of 27 lossy or lossless? compacts file size smaller lossy 22 of 27 lossy or lossless? you can get bac the original file -no changes- lossless 23 of 27 lossy or lossless? removes sound that is outside of human hearing range/ is hard hard for humans to hear lossy 24 of 27 lossy or lossless? small mistakes -digital artefacts- appearing in videos/images lossy 25 of 27 run length encoding: 1= white 0 = black 1110 1110 0000 0000 how would the image be encoded? not - 4 1 1 0 4 1 1 0 5 0 5 0 you would count the 0's all as one if they weren't interrupted: 4 1 1 0 4 1 16 0 is correct 26 of 27 Huffman trees: 0s on the left 1s on the right characters used most often near the top *include spaces* 27 of 27
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