AQA A LEVEL COMPUTER SCIENCE PAPER 2
EXAM 2024/2025 QUESTIONS AND ANSWERS
GRADED A+
what number base is decimal
base 10
what number base is binary
Base 2
what number base is hexadecimal
base 16
what numbers / letters does hexadecimal use
0 - 9 and then A - F
what is binary used for
using computers due to the transistors in the CPU which can either be on or off
,what is a bit represented by
0 or 1 (Usually 1 SO USE ONE)
how big is a byte
8 bits
to multiply a binary number which way do you shift
Left (each shift will be x2 Ex 1 shift is x2, 2 shifts is x4, 3 shifts is x8 etc)
to divide a binary number which way do you shift
Right (each shift will be 2 Ex 1 shift is ÷2, 2 shifts is ÷4, 3 shifts is ÷8 etc)
what is character encoding
because all computers work in binary, All characters must be stored as binary numbers
what is ASCII
(American standard code for information interchange) uses 7 bits giving a character set of 128
characters
,what is Unicode
Unicode uses 16 bits giving a character set of 65,536 - unique code also includes additional symbols and
characters such as emojis
why is Unicode used more compared to ASCII
the ASCII character set is too small to hold every character and symbol in English and other languages
such as Chinese or Arabic
what is a pixel
a picture element
what is colour depth
the more colours an image uses, the more bits per pixel are used
what is the equation for image size
pixels wide x pixels high
what is the file size equation
height in pixels x width in pixels x colour depth per pixel - dividing by 8 will give the value in bytes
, what is the problem for sound in computers
sound is analogue, but must be converted to binary before computers can understand it
what is sampling
measuring amplitude or volume of the sound at a given point in time
what is the amplitude
the height of the sound wave at the time it was sampled
what is the sample rate
the number of samples taken in one second
what is the sample rate measured in
Hertz - 1 Hertz = 1 sample per second
what does a small sampling interval mean
now there is a high sample rate which means better quality sound file which means a larger file
what is sample resolution
EXAM 2024/2025 QUESTIONS AND ANSWERS
GRADED A+
what number base is decimal
base 10
what number base is binary
Base 2
what number base is hexadecimal
base 16
what numbers / letters does hexadecimal use
0 - 9 and then A - F
what is binary used for
using computers due to the transistors in the CPU which can either be on or off
,what is a bit represented by
0 or 1 (Usually 1 SO USE ONE)
how big is a byte
8 bits
to multiply a binary number which way do you shift
Left (each shift will be x2 Ex 1 shift is x2, 2 shifts is x4, 3 shifts is x8 etc)
to divide a binary number which way do you shift
Right (each shift will be 2 Ex 1 shift is ÷2, 2 shifts is ÷4, 3 shifts is ÷8 etc)
what is character encoding
because all computers work in binary, All characters must be stored as binary numbers
what is ASCII
(American standard code for information interchange) uses 7 bits giving a character set of 128
characters
,what is Unicode
Unicode uses 16 bits giving a character set of 65,536 - unique code also includes additional symbols and
characters such as emojis
why is Unicode used more compared to ASCII
the ASCII character set is too small to hold every character and symbol in English and other languages
such as Chinese or Arabic
what is a pixel
a picture element
what is colour depth
the more colours an image uses, the more bits per pixel are used
what is the equation for image size
pixels wide x pixels high
what is the file size equation
height in pixels x width in pixels x colour depth per pixel - dividing by 8 will give the value in bytes
, what is the problem for sound in computers
sound is analogue, but must be converted to binary before computers can understand it
what is sampling
measuring amplitude or volume of the sound at a given point in time
what is the amplitude
the height of the sound wave at the time it was sampled
what is the sample rate
the number of samples taken in one second
what is the sample rate measured in
Hertz - 1 Hertz = 1 sample per second
what does a small sampling interval mean
now there is a high sample rate which means better quality sound file which means a larger file
what is sample resolution
