IGCSE COMPUTER SCIENCE BINARY,
HEX & DATA REPRESENTATION EXAM
QUESTIONS AND ANSWERS
Terabyte - Answer-1 trillion bytes
Gigabyte - Answer-one thousand million bytes.
Byte - Answer-A group of eight bits.
Calculation of Audio File Size - Answer-sample rate (Hz) x bit depth (bits) x length(in
seconds)
JPEG - Answer-Most common graphic file format, full color graphic format (16.7 million
colors) with a relatively small file size
HTML colors - Answer-Defined using a hexadecimal notation (HEX) for the combination
of RGB color values (RGB) (RGB produces hexidecimal)
Data Compression - Answer-A process for reducing the number of bits needed to
represent a piece of information
Sample Rate - Answer-Number of samples taken each second when recording sound.
op code - Answer-triggers the CPU to perform a specific function
operand - Answer-is the data to be used for the operation.
Colour depth - Answer-The number of bits used to represent the colour of a single pixel
in a bitmapped image. Higher colour depth gives a broader range of distinct colours. For
example, an image stored as a .gif file uses 8 bits per pixel so the image could use 256
different colours.
Analogue signal - Answer-a continuous signal that varies in amplitude or frequency with
the information being transmitted
Examples of lossy compression - Answer-MP3 uses lossy compression as it removes
frequencies that our ears cannot tell the difference between, JPEG uses lossy
compression to estimate colours
HEX & DATA REPRESENTATION EXAM
QUESTIONS AND ANSWERS
Terabyte - Answer-1 trillion bytes
Gigabyte - Answer-one thousand million bytes.
Byte - Answer-A group of eight bits.
Calculation of Audio File Size - Answer-sample rate (Hz) x bit depth (bits) x length(in
seconds)
JPEG - Answer-Most common graphic file format, full color graphic format (16.7 million
colors) with a relatively small file size
HTML colors - Answer-Defined using a hexadecimal notation (HEX) for the combination
of RGB color values (RGB) (RGB produces hexidecimal)
Data Compression - Answer-A process for reducing the number of bits needed to
represent a piece of information
Sample Rate - Answer-Number of samples taken each second when recording sound.
op code - Answer-triggers the CPU to perform a specific function
operand - Answer-is the data to be used for the operation.
Colour depth - Answer-The number of bits used to represent the colour of a single pixel
in a bitmapped image. Higher colour depth gives a broader range of distinct colours. For
example, an image stored as a .gif file uses 8 bits per pixel so the image could use 256
different colours.
Analogue signal - Answer-a continuous signal that varies in amplitude or frequency with
the information being transmitted
Examples of lossy compression - Answer-MP3 uses lossy compression as it removes
frequencies that our ears cannot tell the difference between, JPEG uses lossy
compression to estimate colours
