2025 AQA A-LEVEL COMPUTER SCIENCE Paper 2 Question
Paper & Mark Scheme (Merged)
Exam
2025 AQA A-LEVEL COMPUTER SCIENCE Paper 2 Question Paper
Baud Rate - answerThe maximum possible number of signal changes that can occur in
a wire per second.
Bit Rate - answerThe number of bits that can be sent down a wire per second.
Integer - answerA whole number that can be positive, negative or zero.
Examples: -3, 0, 7, 2013588.
Natural (Number) - answerA whole number that is either positive or zero.
Examples: 0, 1, 2, 100, 67238.
Rational (Number) - answerAny number that can be represented as the fraction 'a/b'
where 'a' and 'b' are both integers.
Examples: -0.2, 4/5, 1, 1/3.
Irrational (Number) - answerAny number that cannot be represented as a fraction.
Examples: square root of 2, PI.
Real (Number) - answerAny number that can either be rational or irrational.
Boolean - answerA value that is either true or false.
String - answerA series of characters.
Array - answerA variable that can store multiple values of the same data type.
Example: Storing the high-scores of a game as integers.
Record - answerA variable that can store multiple values that can have different data
types.
,Example: Storing data about a book; a string for the title, an integer for the number of
pages, etc.
Variable - answerA metaphor for it is that is a box that can store a specific type of item
(the data type) and has a name assigned to it (the identifier). Its value can be changed
during run-time of the program.
Constant - answerA metaphor for it is that is a box that can store a specific type of item
(the data type) and has a name assigned to it (the identifier). Its value cannot be
changed during run-time of the program.
Subroutine - answerThis can be broken down into procedures and functions.
Procedure - answerA block of code that performs a specific task that does not return a
value. Parameters can be passed into it.
Function - answerA block of code that performs a specific task that returns a value.
Parameters can be passed into it.
Selection - answerThis is when an if statement or select case is used to, for example,
check the value of a variable.
Iteration - answerThis is when, within the program, there is a loop.
Definite Iteration - answerThe number of times that the program will loop is already
specified.
Example: For loop.
Indefinite Iteration - answerThe number of times the program will loop is unknown.
Example: Do loop.
Nested (structures) - answerThis is when either iterative or selective statements are put
inside of each other.
Meaningful Identifiers - answerSubroutines, variables and objects should have sensible
names.
Real Division - answerFinds the value (usually as a decimal) of one number divided by
another.
Integer Division - answerFinds the integer part of one number divided by another.
Integer Remainder - answerFinds the remainder of one number divided by another.
, Truncation - answerChops the decimal part off a number.
Floor - answerRounds a number down to the nearest integer.
Ceiling - answerRounds a number up to the nearest integer.
AND - answerLogical Operation:
Returns true only when both values are true.
OR - answerLogical Operation:
Returns true as long as at least one of the values are true.
XOR - answerLogical Operation:
Returns true only when exactly one of the two values is true and not both.
NOT - answerLogical Operation:
Returns true if the value is false and returns false if the value is true.
Exception Handling - answerWhen a try catch is used in the program to deal with any
errors that may occur.
ByVal - answerWhen a variable is passed into a subroutine as a copy so its value will
not be changed.
ByRef - answerWhen a variable is passed into a subroutine as a reference so its value
can be changed.
Local (Variable) - answerA variable that is defined, for example, within a subroutine and
cannot be viewed or modified from outside of the block of code is was declared in.
Global (Variable) - answerA variable that is declared, usually at the start of the program,
and can be accessed and modified from anywhere at all in the program.
Recursion - answerA subroutine's definition contains a self-call meaning a function or
procedure calls itself as a way of performing iteration.
Object-Oriented (Programming) - answerA type of programming paradigm when
multiple objects are created and handled to run the program.
Example: In a game you might have an object for the player and then multiple objects
for the enemies.
Procedural (Programming) - answerA type of programming paradigm when you break
down a project, usually using a decomposition diagram, into individual tasks which can
each be performed by a procedure.
Paper & Mark Scheme (Merged)
Exam
2025 AQA A-LEVEL COMPUTER SCIENCE Paper 2 Question Paper
Baud Rate - answerThe maximum possible number of signal changes that can occur in
a wire per second.
Bit Rate - answerThe number of bits that can be sent down a wire per second.
Integer - answerA whole number that can be positive, negative or zero.
Examples: -3, 0, 7, 2013588.
Natural (Number) - answerA whole number that is either positive or zero.
Examples: 0, 1, 2, 100, 67238.
Rational (Number) - answerAny number that can be represented as the fraction 'a/b'
where 'a' and 'b' are both integers.
Examples: -0.2, 4/5, 1, 1/3.
Irrational (Number) - answerAny number that cannot be represented as a fraction.
Examples: square root of 2, PI.
Real (Number) - answerAny number that can either be rational or irrational.
Boolean - answerA value that is either true or false.
String - answerA series of characters.
Array - answerA variable that can store multiple values of the same data type.
Example: Storing the high-scores of a game as integers.
Record - answerA variable that can store multiple values that can have different data
types.
,Example: Storing data about a book; a string for the title, an integer for the number of
pages, etc.
Variable - answerA metaphor for it is that is a box that can store a specific type of item
(the data type) and has a name assigned to it (the identifier). Its value can be changed
during run-time of the program.
Constant - answerA metaphor for it is that is a box that can store a specific type of item
(the data type) and has a name assigned to it (the identifier). Its value cannot be
changed during run-time of the program.
Subroutine - answerThis can be broken down into procedures and functions.
Procedure - answerA block of code that performs a specific task that does not return a
value. Parameters can be passed into it.
Function - answerA block of code that performs a specific task that returns a value.
Parameters can be passed into it.
Selection - answerThis is when an if statement or select case is used to, for example,
check the value of a variable.
Iteration - answerThis is when, within the program, there is a loop.
Definite Iteration - answerThe number of times that the program will loop is already
specified.
Example: For loop.
Indefinite Iteration - answerThe number of times the program will loop is unknown.
Example: Do loop.
Nested (structures) - answerThis is when either iterative or selective statements are put
inside of each other.
Meaningful Identifiers - answerSubroutines, variables and objects should have sensible
names.
Real Division - answerFinds the value (usually as a decimal) of one number divided by
another.
Integer Division - answerFinds the integer part of one number divided by another.
Integer Remainder - answerFinds the remainder of one number divided by another.
, Truncation - answerChops the decimal part off a number.
Floor - answerRounds a number down to the nearest integer.
Ceiling - answerRounds a number up to the nearest integer.
AND - answerLogical Operation:
Returns true only when both values are true.
OR - answerLogical Operation:
Returns true as long as at least one of the values are true.
XOR - answerLogical Operation:
Returns true only when exactly one of the two values is true and not both.
NOT - answerLogical Operation:
Returns true if the value is false and returns false if the value is true.
Exception Handling - answerWhen a try catch is used in the program to deal with any
errors that may occur.
ByVal - answerWhen a variable is passed into a subroutine as a copy so its value will
not be changed.
ByRef - answerWhen a variable is passed into a subroutine as a reference so its value
can be changed.
Local (Variable) - answerA variable that is defined, for example, within a subroutine and
cannot be viewed or modified from outside of the block of code is was declared in.
Global (Variable) - answerA variable that is declared, usually at the start of the program,
and can be accessed and modified from anywhere at all in the program.
Recursion - answerA subroutine's definition contains a self-call meaning a function or
procedure calls itself as a way of performing iteration.
Object-Oriented (Programming) - answerA type of programming paradigm when
multiple objects are created and handled to run the program.
Example: In a game you might have an object for the player and then multiple objects
for the enemies.
Procedural (Programming) - answerA type of programming paradigm when you break
down a project, usually using a decomposition diagram, into individual tasks which can
each be performed by a procedure.
