1.2.3 Units (bits and bytes)

Question 1

Why does data need to be stored as binary? (1)

Answer 1

Computers can only understand binary (1)

Question 2

How do you calculate the size of a sound file? (3)

Answer 2

Sample rate (1) x duration in seconds (1) x bit depth (1)

Question 3

How do you calculate the size of an image file? (3)

Answer 3

Colour depth (1) x image height in pixels (1) x image width in pixels (1)

Question 4

How do you calculate the size of a text file? (2)

Answer 4

Bits per character (1) x number of characters (1)

Question 5

What are the units of file sizes, smallest to largest? (8)

Answer 5

Bit Nibble Byte Kilobyte Megabyte Gigabyte Terabyte Petabyte

Question 6

How many bits in a byte? (1)

Answer 6

8

Question 7

How many bits in a nibble? (1)

Answer 7

4

Question 8

How do you convert from a unit of file size to a larger unit?

Answer 8

Divide by 1000 per step (unless it’s nibbles or bits to byte)

Question 9

How do you convert from a unit of file size to a smaller unit?

Answer 9

Multiply by 1000 per step (unless it’s bytes to nibble / bit)