U4 - GRAPHICS & SOUND

Question 1

NAME THE 5 DATA TYPES ?

Answer 1

Boolean
Float / Real
Integer
Character
String

Question 2

WHAT ARE RASTER IMAGES MADE ?

Answer 2

Raster images are made from a dot matrix of data representing a grid of pixels

Question 3

PROS / CONS OF RASTER

Answer 3

• Pixels can be individually edited
• Lose quality when scaled up
• Take up more storage space

Question 4

WHAT ARE VECTORS IMAGES ?

Answer 4

• Graphics made using mathematical formulas
• Popular in logo design

Question 5

PROS / CONS OF VECTOR

Answer 5

• Can be scaled up without a loss of quality
• Smaller amount of memory needed to store
• More complicated to make

Question 6

WHAT IS RESOLUTION ?

Answer 6

• The number of dots/ pixels per inch (dpi)
• The greater the image the more defined an image is but also more file space needed

Question 7

HOW DO YOU CALCULATE IMAGE SIZE ?

Answer 7

Colour Depth x Img Height x Img Width

Question 8

COLOUR DEPTH

Answer 8

How many bits a colour pixel is

Question 9

HOW MANY BITS ARE TRUE COLOUR DISPLAYS ?

Answer 9

24 BITS (RGB Colour Sliders)

Question 10

WHY IS SOUND CONVERTED FROM ANALOGUE TO DIGITAL ?

Answer 10

Computers cannot understand analogue sound. It must be converted into discrete digital data through sampling

Question 11

WHAT IS SAMPLING ?

Answer 11

The amplitude of an analogue sound is sampled at set intervals and recorded as digital data.

Question 12

WHAT IS SAMPLING RATE ?

Answer 12

The number of times a sound is sampled per SECOND (Hz)

Question 13

WHAT IS BIT DEPTH ?

Answer 13

Number of bits used to store each sample.

Question 14

WHAT IS DURATION ?

Answer 14

How many seconds of audio in a file

Question 15

HOW DO YOU CALCULATE SOUND FILE SIZE ?

Answer 15

Sample Rate (Hz) x Bit Depth (bits) x Duration (s)

Question 16

WHAT DOES ASCII STAND FOR ?

Answer 16

American Standard Code for Information Interchange

Question 17

WHAT DOES ASCII DO ?

Answer 17

Standardised character sets allow for data interchange between different programs

Question 18

HOW MANY BITS DOES ASCII USE ?

Answer 18

7 bit

Question 19

WHAT IS UNICODE ?

Answer 19

Uses 32-bit in order to represent all language characters
Original 128 ASCII characters are the same
Unicode uses more memory to store a character

Question 20

NAME 6 VALIDATION CHECKS

Answer 20

PRESENCE CHECKS
FORMAT CHECKS
LENGTH CHECKS
TYPE CHECKS
RANGE CHECK

Question 21

PRESENCE CHECK

Answer 21

Prevents further progress if a required field is left blank

Question 22

FORMAT CHECKS

Answer 22

ENSURES DATA MATCHES A SPECIFIC PATTERN i.e dd/mm/yyyy

Question 23

LENGTH CHECKS

Answer 23

Used to ensure input data is a sensible length .i.e. First name is between 3-16 characters

Question 24

TYPE CHECKS

Answer 24

Ensures inputted data is the correct data type

Question 25

RANGE CHECKS

Answer 25

Ensures input data lays within a specific range

Question 26

TWO WAYS TO VERIFY CODE

Answer 26

Double keying (two different transcripts made - compared for errors )
Proof reading

Question 27

1D ARRAYS

Answer 27

A collection of related data all of ONE DATA TYPE. Lists in python. Can hold a fixed number of items

Question 28

2D ARRAYS

Answer 28

SAME DATA TYPE - Like a table