Section Seven: Data Representation

Question 1

Overflow

Answer 1

When you get a result that requires more bits than the CPU is expecting during binary arithmetic
Bits overflowing can lead to loss of accuracy/data

Question 2

Binary Shift

Answer 2

Moves every bit in a binary number left or right a certain number of places
Left muLtipLy
RIght dIvIde

Question 3

Why programmers prefer to use hex

Answer 3

Easier to remember large numbers
Less chance of input errors
Easier to convert to binary

Question 4

Character set

Answer 4

Collections of characters that a computer recognises from their binary representation

Question 5

Colour depth

Answer 5

Number of bits used for each pixel

Question 6

Resolution

Answer 6

Density of pixels in an image

Question 7

Metadata

Answer 7

The information stored in an image file which helps the computer recreate the image on screen from the binary data in each pixel.
E.g. File’s format, height, width, colour depth, resolution

Question 8

Sampling intervals

Answer 8

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

Question 9

Sampling frequency

Answer 9

The amount of samples taken per second (KHz)

Question 10

Bit rate + equation

Answer 10

The number of bits used per second of audio

Bit rate = sampling frequency x sample size

Question 11

Data compression

Answer 11

Making file size smaller while trying to make the file size as true to the original as possible

Question 12

Lossy Compression

Answer 12

Permanently removes data from the file

Limits the number of bits the file needs

Question 13

Lossless Compression

Answer 13

Temporarily removes data to store the file then restoring it to its original state when its opened