Data representation - Binary (OCR GCSE Computer Science)

Why do computers use binary (select the BEST answer)

• It's the only language they understand

• It's a series of 1's and zeros (on or off) which activate little switches inside the CPU

• The CPU is constructed from little switches called transistors which are activated through electrical signals which are either on or off

• Lego

How many different colours could be represented in an image which uses 8 bits per pixel

• 255

• 256

• 127

• 128

Which of the following is NOT valid hexadecimal

• 003DFG

• DEADBEEF

• C0FFEE

• B12EADB0A12D

Convert the denary number 36 to a byte

• 100100

• 00100100

• 00100101

• 100101

What is the denary value 321 expressed as a byte?

• 11111111

• 10100001

• 01000001

• 321 cannot be expressed as a byte

Convert the binary number 00101101 to hexadecimal

• 2D

• D2

• 3B

• FF

Convert the denary number 67 to hexadecimal

• 43

• AB

• 4G

• 67

Convert the hexadecimal value 51 to denary

• 81

• A3

• 15

• 38

Which TWO factors control the quality of uncompressed digitised audio?

• Sampling frequency

• Bit-depth

• Filesize

• The type of compression used

Convert the hexadecimal value EA to binary

• 11101010

• 11001111

• 10101011

• 10101110