AQA GCSE Computer Science Data Representation

Modern computers work in binary because it is easy to represent two states in simple electronic circuits. Binary is a...

• ...base 2 number system with 2 symbols

• ...base 6 number system with 6 symbols

• ...base 10 number system with 10 symbols

• ...base 4 number system with 4 symbols

Each digit in binary is called a...

• byte

• nibble

• bit

• kilobyte

A group of 8 binary bits is called a...

• byte

• bit

• nibble

A group of 4 binary bits is called a...

• bit

• byte

• nibble

How many kilobytes in a megabyte?

• 1000

• 1028

• 1024

• 1026

Why use hexadecimal instead of binary?

• It is easier to use as it summarises four binary numbers in one character

• It takes up less memory

• It is faster for a CPU to process

If a computer has only 8 bits to store a value then the last bit of a 9 bit number will be lost. This is called...

• an over error

• an overflo error

• an overflow error

• an underflow error

Hexadecimal numbers are...

• base 12

• base 14

• base 16

• base 18

All symbols displayed in a computer are represented by a code. The computer looks up the symbol matching the code from a list of codes and their associated characters. The list of code and characters is called the...

• character set

• character collection

• character group

• character assemble

ASCII uses...

• 7 bits so can provide 127 characters or symbols plus the null character (128 in total)

• 7 bits so can provide 127 characters or symbols

• 7 bits so can provide 127 characters plus the null characters plus the null character (128 in total)