Data Representation

Question 1

1 bit =
• 1 byte =
• A nibble =
• 1 kB (kilobyte) =
• 1 MB (megabyte) =
• 1 GB (gigabyte) =
• 1 TB (terabyte) =
• 1 PB (petabyte) =

Answer 1

1 bit = a single 0 or 1
• 1 byte = 8 bits = 1 character of text
• (A nibble = 4 bits or half a byte)
• 1 kB (kilobyte) = 1000 bytes
• 1 MB (megabyte) = 1000 kB or 1000x1000 bytes
• 1 GB (gigabyte) = 1000 MB
• 1 TB (terabyte) = 1000 GB
• 1 PB (petabyte) = 1000 TB

Question 2

Deneary to Binary

a) 18

b) 57

Answer 2

a) 10010
b) 111001

Question 3

Show the possivle combinatioms or states per bit:

1 bit =
2 bits =
3 bits =

Answer 3

1 bit = 2
2 bits = 4
3 bits = 8

Question 4

What is 1001 (binary) in denary?

Answer 4

9

Question 5

How do you know if binary numbers are even or odd?

Answer 5

Even numbers have a 0 at the end and odd numbers have a 1

Question 6

How do you translate 2A hex to denary?

Answer 6

2 x 16 = 32
Add the A equal to 10
= 42

Question 7

How to convert denary to hex.

Answer 7

Divide the denary number by 16 and the remained will be the last digit

E.g 18/16 = 1 r 2 so the hex value for 18 is 12

Question 8

Binary to hex conversion

Answer 8

Divide the binary into two nibbles of 4 bits and then convert each nibble to it’s hex value. Eg

11100101 ~> 1110 = E in hex and 0101 = 5 in hex therefore 11100101 = E5

Question 9

Advantages of using Hex?

Answer 9

• Much easier to remember a hex value than a binary value
• Quicker to type or write hex
• Easy to convert between Hex and binary
• People make less errors with fewer digits

Question 10

Binary addition rules:
0 + 0 =
0 + 1 =
1 + 0 =
1 + 1 =
1 + 1 + 1 =

Answer 10

0 + 0 = 0
0 + 1 = 1
1 + 0 = 1
1 + 1 = 0 Carry 1
1 + 1 + 1 = 1 Carry 1

Question 11

What does a left and right binary shift do?

Answer 11

Left shifts multipy and right shifts divide by 2

Question 12

What error does it cause when an addition is too large?

Answer 12

Overflow error

Question 13

What are the two main character sets?

Answer 13

ASCII and Unicode

Question 14

Types of bitmap image file formats

Answer 14

BMP, JPG, GIF, PNG

Question 15

Type of vector format

Answer 15

SVG

Question 16

What is a pixel?

Answer 16

The smallest identifiable area of an image

Question 17

What is image resoloution?

Answer 17

The concentration of pixels within a specific area

Question 18

How to calculate the amount of colours in a pixel

Answer 18

If there are 8 bits per pixel = 2^8 = 256 colours
2 to the power of the amoumts of bits per pixel(n) are equal the the amount of colours. n in this case if referring to bit depth

Question 19

In 32 bit colour what are the last 8 bits for?

Answer 19

Given to a transparency channel to allow background to show through

Question 20

What is metadata?

Answer 20

Informatiom other than image data is stored with a file including: Date created, author, resoloution, colour depth per pixel

Question 21

What is analogue to digital converision?

Answer 21

Analouge sound signals are continuous and digital signals are discrete. Sound is digitized by repeatedly measuring and recording the sound wave

Question 22

Calculating sound file sizes

Answer 22

File size bits = sample rate (per second) x bit depth x duration (s)

File size / 8 = to amnt in bytes