Binary,Hex,Logic gates, images, sound, compression Flashcards Preview

Computer Science OCR > Binary,Hex,Logic gates, images, sound, compression > Flashcards

Flashcards in Binary,Hex,Logic gates, images, sound, compression Deck (46)
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1

how many values can a single bit represent?

2 - 1 and 0

2

how many bits are in a nibble?

4 bits

3

how many bits are in a byte?

8 bits

4

what values are used in a binary converting table of 8 bits?

1,2,4,8,16,32,64 and 128

5

How many values can 8 bits represent?

256

6

what would the sum of the binary numbers 00110011 and 01000010 equal?

01110101

7

What would a one place right shift do to a binary number?

Divide the number by 2 (half)

8

What would a one place left shift do to a binary number?

Multiply the number by 2 (Double)

9

what does F stand for in denary numbers?

15

10

what does A stand for in denary numbers?

10

11

What can Hexadecimal also be called and why?

Base-16, because it uses sixteen different didgets

12

What is ASCII?

The most commonly used character set in the English speaking world. Each ASCII character is given a 7-bit binary code - it can represent 128 different characters.

13

What is Extended ASCII?

a character set which gives each character and 8-bit binary code, allowing for 256 characters to be represented, useful for many European languages like french and German that include accents on some vowels. The first 128 characters are the same order as the ASCII characters.

14

what is Unicode?

a 16 - 32 bit character set, it tries to cover every written language, and covers all major languages, even those that use a completely different alphabet like Greek or Russian.

15

What is the relationship between the number of bits and the colour depth of an image?

The more bits = the deeper colour depth

16

how many colours can a 1-bit, 4-bit and 24-bit image show?

2^1 = 2 colours
2^4 = 16 colours
2^24 = 16,777,216 colours

17

What is colour depth?

The number of bits used for each pixel

18

What is MetaData?(images)

the information stored in an image file which helps the computer recreate the image on screen from the binary data in each pixel, it is needed to display images on a screen

19

What is a bitmap image?

the type of image you use most often, and made up of lots of tiny dots called pixels.

20

What is Resolution?

Resolution is the density of pixels in an image, like how many pixels are within a certain area. The higher he resolution the better the quality of the image

21

What is resolution measured in?

measured in dots per inch (DPI)

22

How is sound recorded?

By a microphone as an analogue signal

23

What is an Analogue Signal?

Pieces of continually changing data (sound)

24

What do Analogue signals need to be converted to? (sound)

Digital data so computers can store and read sound files, done by analogue to signal converters.

25

What is the process of converting analogue to digital called?

Sampling

26

What is a sampling interval?

The gaps between each end of the points where the analogue recording is sampled.

27

If an audio is sampled every 5 milliseconds, what would the sampling interval be?

5 ms

28

What is sample frequency?

Sample frequency (sample rate) is how many samples you take in a second, usually measured in Kilohertz (KHz)

29

what links bit rate, sampling frequency and sample size?

bit rate = sampling frequency x sample size

30

what happens the higher the sampling frequency?

the higher the sampling frequency, the better the quality of the original recording