data rep+fundamentals of algorithm

Question 1

number base

Answer 1

-number of digits used to represent numbers

Question 2

decimal number base

Answer 2

-base of 10

Question 3

binary number base

Answer 3

-base=2

Question 4

hexadecimal number base

Answer 4

-base value 16

Question 5

purpose of hexadecimal

Answer 5

-large numbers can be shown with fewer digits
-used to show memory addresses

Question 6

using hexadecimal to write numbers

Answer 6

if number >16, divide by 16 and use the amt it divided by, and the remainder, use each number as a hex
i.e:
8 to hexadecimal:
8

22 to hex:
22/16 = 1 remainder 6
1=Hex 1
6 = hex 6
ans=16

Question 7

bit

Answer 7

smallest unit of data, rep by 1

Question 8

byte

Answer 8

8 bits

Question 9

Kilobyte

Answer 9

1000 bytes

Question 10

megabyte

Answer 10

1000 kilobytes

Question 11

gigabyte

Answer 11

1000 megabytes

Question 12

petabyte

Answer 12

1000 gigabyte

Question 13

character set

Answer 13

-defined post of recognised characters that can be stored in a computer system

Question 14

ASCII

Answer 14

—uses 7 bits, up to 128

Question 15

unicode

Answer 15

-uses 2 bytes, uo to 65k+ characters, universal character set

Question 16

pixel

Answer 16

-single point in an image, 1 pixel=1 binary code

Question 17

what factors affect file size?

Answer 17

size:
le image=larger file
colour depth:
-more colour depth = larger image file

Question 18

analogue

Answer 18

data that varies in value

Question 19

sound sampling

Answer 19

process where analogie wave is converted to digital signal

Question 20

sampling rate

Answer 20

-measured in Hz
-number of samples/second taken from analogue signal to convert it to digital

Question 21

sample resolution

Answer 21

-number of bits used to represent each sample

Question 22

calculating file size

Answer 22

sample resolution x rate x length

Question 23

data compression

Answer 23

-reducing data size but keeping most/all info
—faster transmission, saves space

Question 24

huffman trees

Answer 24

-lossless compression
-follow path, most used at top, least popular at bottom
-find total, x by frequency, compare with how much would’ve taken in ascii

Question 25

RLE run length coding

Answer 25

-lossless compression
-freq table, where how many times show up in a row
e.g:
book = b(1) o (2) k (1)
-good for large texts, images w same colour

Question 26

algorithm

Answer 26

set of instructions for carrying out a task

Question 27

flowchart symbols

Answer 27

-rectangle=process/instruction
-parallelogram=input/output
-diamond=decision
-oval=start/stop
-weird rectangle w lines=subroutine

Question 28

decomposition

Answer 28

-breaking problem into smaller, more manageable chunks

Question 29

abstraction

Answer 29

-removing unnecessary detail from problem

Question 30

efficiency

Answer 30

-shorter=more efficient