1.2 text, sound and images

Question 1

how does a computer represent text

Answer 1

text converted to binary to be processed by computer

Question 2

unicode vs ASCII

Answer 2

• unicode allow greater range of characters and symbols
• unicode require more bits per character

Question 3

how does computer represent sound

Answer 3

sound wave sampled (convert analogue wave into digital signal). processed by computer

Question 4

what is sample rate and resolution in sound file, what effect does increase have

Answer 4

sample rate: number of samples taken a second

sample resolution: number of bits per sample

increase file size and accuracy of recording

Question 5

what is an image

Answer 5

series of pixels that are converted to binary, which is processed by a computer

Question 6

what is resolution and colour depth in image, how does increase affect

Answer 6

resolution: number of pixels in image
colour depth: number of bits used to represent each colour

file size and image quality increase

Question 7

describe what is meant by a character set

Answer 7

• All characters and symbols that can be represented by computer system
• each character and symbol assigned unique value