AQA A-Level Computer Science 4.5 Fundamentals of data representation overview quiz quiz

$13$

$9$

$11$

$15$

It uses sixteen symbols so it can store more distinct values per digit

It is the low level language the processor actually fetches and executes

It can directly represent negative numbers without any extra encoding

Each hexadecimal digit represents exactly four bits

Invert all the bits and add 1

Invert all the bits only

Add 1 only

Reverse the order of the bits

It always offers higher precision than fixed point for the same number of bits

It can represent a much larger range of numbers for the same number of bits

It never suffers from rounding errors when storing fractional values

It is far simpler to implement in hardware than fixed point arithmetic

$8$

$16$

$128$

$256$

They are identical

A kilobyte is 1024 bytes; a kibibyte is 1000 bytes

A kilobyte is 1000 bytes; a kibibyte is 1024 bytes

A kibibyte is 8 bits

$7$ bits

$5$ bits

$8$ bits

$16$ bits

To make text files significantly smaller than they are under ASCII

To give every character in every writing system a unique code

To replace binary storage with hexadecimal across all modern computers

To remove the need for any character set when encoding plain text

$5000$ bits

$2000$ bits

$20000$ bits

$200000$ bits

Both methods always restore the exact original file when it is decompressed

Lossy restores the exact original; lossless permanently discards some data

Neither method actually reduces the overall file size when applied to data

Lossless restores the exact original; lossy permanently discards some data

One shared key for both encryption and decryption

A public key to encrypt and a private key to decrypt

No keys are needed

A different key for every byte