Learn Extracted exam questions A-Level Computer Science 9618 Computer Science November 2025 Question Paper 31
9618 Computer Science November 2025 Question Paper 31
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The composite record data type, \texttt{ClubMember}, is defined in pseudocode as:
\begin{alltt} TYPE ClubMember DECLARE Code : INTEGER DECLARE LastName : STRING DECLARE FirstName : STRING DECLARE Telephone : STRING DECLARE JoinDate : DATE DECLARE Fees : REAL DECLARE FeesPaid : BOOLEAN ENDTYPE \end{alltt}
Write the pseudocode statement to set up a variable for one record of the composite data type, \texttt{ClubMember}.
Write the pseudocode statements to assign the following values to the variable set up in part (a)(i):
\begin{itemize} \item 984632 to \texttt{Code} \item \texttt{TRUE} to \texttt{FeesPaid} \end{itemize}
An enumerated data type, \texttt{Activity}, is required, so that a new field, \texttt{Choice}, can be added to the composite data type, \texttt{ClubMember}, to allow members to choose an activity.
Write the pseudocode statement for the type declaration of \texttt{Activity} to hold the names of the available activities:
Badminton, Football, Golf, Snooker, Swimming, Tennis.
Write the new pseudocode statement required to update the declaration of \texttt{Choice} in the definition of \texttt{ClubMember}.
Numbers are stored in a computer system using binary floating-point representation with:
\begin{itemize} \item 12 bits for the mantissa \item 4 bits for the exponent \item two's complement form for both the mantissa and the exponent. \end{itemize}
Write the normalised floating-point representation of the following positive binary number using this system.
\textbf{Mantissa} \hfill \textbf{Exponent}
\framebox{$\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square$} \hfill \framebox{$\square\,\square\,\square\,\square$}
Calculate the normalised binary floating-point representation of $-76.1875$ in this system. Show your working.
\textbf{Mantissa} \hfill \textbf{Exponent}
\framebox{$\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square$} \hfill \framebox{$\square\,\square\,\square\,\square$}
Explain why protocols are essential for communication between computer systems.
POP3 is an email communication protocol.
Identify and describe \textbf{two} other communication protocols that are used when sending or receiving emails.
Protocol 1 \hrulefill
Description \hrulefill
Protocol 2 \hrulefill
Description \hrulefill
Describe \textbf{two} ways in which packet switching ensures a complete message is received when passing messages across a network.
- \hrulefill
- \hrulefill
A scheduling routine determines how processes are managed by the operating system.
Identify \textbf{two} scheduling routines.
- \hrulefill
- \hrulefill
Describe \textbf{two} ways in which the complexities of the computer hardware are hidden from the user.
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- \hrulefill
Identify \textbf{two} items commonly found within a digital certificate.
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Explain why a digital certificate is required to validate a digital signature.
The diagram shows a logic circuit.
Complete the truth table for the given logic circuit. Show your working.
\begin{tabular}{|c|c|c|c|c|c|c|c|} \hline \multicolumn{3}{|c|}{} & \multicolumn{4}{c|}{\textbf{Working space}} & \ \hline \textbf{A} & \textbf{B} & \textbf{C} & \textbf{P} & \textbf{Q} & \textbf{R} & \textbf{S} & \textbf{Z} \ \hline 0 & 0 & 0 & & & & & \ \hline 0 & 0 & 1 & & & & & \ \hline 0 & 1 & 0 & & & & & \ \hline 0 & 1 & 1 & & & & & \ \hline 1 & 0 & 0 & & & & & \ \hline 1 & 0 & 1 & & & & & \ \hline 1 & 1 & 0 & & & & & \ \hline 1 & 1 & 1 & & & & & \ \hline \end{tabular}
Complete the Karnaugh map (K-map) for the Boolean expression:
Complete the Karnaugh map (K-map) for the Boolean expression:
\begin{tabular}{cc|c|c|c|c|} & \multicolumn{5}{c}{\textbf{BC}} \ \textbf{A} & & \textbf{00} & \textbf{01} & \textbf{11} & \textbf{10} \ \cline{2-6} & \textbf{0} & & & & \ \cline{2-6} & \textbf{1} & & & & \ \cline{2-6} \end{tabular}
Draw loop(s) around appropriate group(s) in the K-map to produce an optimal sum-of-products.
Write the Boolean expression from your answer to part \textbf{b(ii)} as a simplified sum-of-products. Do \textbf{not} carry out any further simplification.
Identify one Artificial Intelligence (AI) algorithm to find the shortest distance between two points on a graph.
Identify one Artificial Intelligence (AI) algorithm to find the shortest distance between two points on a graph.
Describe Deep Learning.
Outline the purpose of lexical analysis during the compilation of a program.
Write the Reverse Polish Notation (RPN) for the given infix expression:
$(2 - 6) * (13 + 7) / 5$
The RPN expression:
\texttt{d a b + * c a - /}
is to be evaluated, where:
$a = 6$, $b = 12$, $c = 15$ and $d = 5$.
Show the changing contents of the stack as the RPN expression is evaluated.
\begin{tabular}{ccccccccc} \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} \ \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} \ \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} \ \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} \ \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} & \framebox{\quad} \end{tabular}
A stack has been implemented using pseudocode to store a maximum of 100 string items using the global variables in the following table:
\begin{tabular}{|c|c|c|c|} \hline \textbf{Identifier} & \textbf{Data type} & \textbf{Description} & \textbf{Initialisation value} \ \hline Base & INTEGER & pointer for the bottom of the stack & 0 \ \hline Top & INTEGER & pointer for the top of the stack & -1 \ \hline StackArray & STRING & 1D array to implement the stack & [0:99] \ \hline Max & INTEGER & maximum number of items in the stack & 100 \ \hline \end{tabular}
The value of \texttt{Top} is incremented each time a data item is added to the stack and decremented every time a data item is removed.
Complete the \textbf{pseudocode} for the function to remove a data item from the stack.
\begin{alltt} FUNCTION Pop() \hrulefill DECLARE DataItem : STRING DataItem <- ""
IF \hrulefill THEN
DataItem <- \hrulefill
Top <- \hrulefill
ELSE
DataItem <- "You cannot remove data; the stack is empty"
ENDIF
\hrulefill
ENDFUNCTION \end{alltt}
Write the \textbf{pseudocode} to output the data item removed from the stack with an appropriate message.
A stack is used to implement recursion.
State the \textbf{three} essential features of recursion.
- \hrulefill
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Explain what is meant by \textbf{exception handling}. Include an example of a possible cause of an exception in your answer.
Explanation \hrulefill
Example \hrulefill
The table shows assembly language instructions for a processor that has one register, the Accumulator (ACC).
\begin{tabular}{|l|l|l|l|} \hline \textbf{Label} & \textbf{Opcode} & \textbf{Operand} & \textbf{Explanation} \ \hline & LDM & #n & Load the number n to ACC \ \hline & LDD & \texttt{
} & Load the contents of the location at the given address to the ACC \ \hline & LDI & \texttt{} & The address to be used is at the given address. Load the contents of this second address to the ACC \ \hline & ADD & \texttt{} & Add the contents of the given address to the ACC \ \hline & SUB & \texttt{} & Subtract the contents of the given address from the ACC \ \hline & STO & \texttt{} & Store the contents of the ACC at the given address \ \hline \texttt{Write \textbf{assembly language} code, using \textbf{only} the given instruction set to:
\begin{itemize} \item store the denary value 100 as a named constant \item subtract the constant from the value contained in address 632 \item store the result in variable \texttt{Answer}. \end{itemize}
Show the initialisation of the constant and \texttt{Answer} in the table provided.
\begin{tabular}{|c|c|} \hline \textbf{Label} & \textbf{Contents} \ \hline & \ \hline & \ \hline & \ \hline & \ \hline \end{tabular}
The address 632 contains the value 45.
State the value of \texttt{Answer} after the code described in part \textbf{(a)} has executed.