9618 Computer Science November 2025 Question Paper 11

1 short_answer p. 2

1a short_answer p. 2

1ai 1 mark calculation p. 2 1.1

Convert the binary number into hexadecimal.

101100111010 \hrulefill

1aii 1 mark calculation p. 2 1.1

Convert the denary number into Binary Coded Decimal (BCD).

108 \hrulefill

1aiii 2 marks calculation p. 2 1.1

Convert the 12-bit two’s complement binary integer into denary.

Show your working.

111110111100

Denary value \hrulefill

1b short_answer p. 3

The following binary addition is performed using 8-bit registers.

1bi 1 mark calculation p. 3 1.1

Complete the calculation using binary addition.

$$\begin{array}{r} 10110011 \\ + 01111000 \\ \hline \end{array}$$

1bii 2 marks short_answer p. 3 1.1

Name and describe the error that can occur when binary addition is performed.

2 short_answer p. 4

A relational database, \texttt{WORKEXPERIENCE}, stores data about students and the companies where they complete work experience.

Students can complete multiple work experience placements but can only complete one placement at a time.

Students can complete more than one placement at the same company.

Part of the database is shown:

\texttt{STUDENT(StudentID, FirstName, TelephoneNumber, UniversityName)}

\texttt{PLACEMENT(PlacementID, StudentID, CompanyID, StartDate, EndDate, Complete)}

\texttt{COMPANY(CompanyID, CompanyName, MaxStudentsPerPlacement)}

2a 2 marks short_answer p. 4 8.1

Complete the entity-relationship (E-R) diagram for the database \texttt{WORKEXPERIENCE}.

2b 2 marks short_answer p. 4 8.1

Explain why the database \texttt{WORKEXPERIENCE} is in Third Normal Form (3NF).

2c short_answer p. 5

Some example data from the \texttt{PLACEMENT} table is shown:

\begin{tabular}{|l|l|l|l|l|l|} \hline \textbf{PlacementID} & \textbf{StudentID} & \textbf{CompanyID} & \textbf{StartDate} & \textbf{EndDate} & \textbf{Complete} \ \hline PC001 & LDEA01 & MSCM & 01/01/2023 & 12/07/2023 & TRUE \ \hline PC002 & LDEA01 & MSCM & 01/04/2024 & 08/05/2024 & FALSE \ \hline PC003 & ALAU02 & NEAM & 09/03/2020 & 10/03/2021 & FALSE \ \hline PC004 & LOLI75 & GOUZ & 07/06/2018 & 11/09/2018 & TRUE \ \hline \end{tabular}

2ci 2 marks short_answer p. 5 8.3

Write a Structured Query Language (SQL) script to delete all placements that have been completed.

2cii 4 marks short_answer p. 5 8.3

Write an SQL script to return the total number of placements completed by the student with ID LDEA01 at the company with ID NEAM. The total should be given an appropriate name.

2d 3 marks short_answer p. 6 8.1

The database tables are repeated here:

\texttt{STUDENT}(\underline{\texttt{StudentID}}, \texttt{FirstName}, \texttt{TelephoneNumber}, \texttt{UniversityName})

\texttt{PLACEMENT}(\underline{\texttt{PlacementID}}, \texttt{StudentID}, \texttt{CompanyID}, \texttt{StartDate}, \texttt{EndDate}, \texttt{Complete})

\texttt{COMPANY}(\underline{\texttt{CompanyID}}, \texttt{CompanyName}, \texttt{MaxStudentsPerPlacement})

Explain what is meant by referential integrity, and how it applies to this database.

3 short_answer p. 7

3a 2 marks short_answer p. 7 3.2

Draw a logic circuit for the logic expression:

$$X = \text{NOT } ((A \text{ NAND } B) \text{ XOR } (\text{NOT } A \text{ OR } \text{NOT } C))$$

3b 2 marks short_answer p. 7 3.2

Write the logic expression for the following truth table.

\begin{tabular}{|c|c|c|c|} \hline \textbf{R} & \textbf{S} & \textbf{T} & \textbf{Q} \ \hline 0 & 0 & 0 & 0 \ \hline 0 & 0 & 1 & 1 \ \hline 0 & 1 & 0 & 0 \ \hline 0 & 1 & 1 & 0 \ \hline 1 & 0 & 0 & 0 \ \hline 1 & 0 & 1 & 0 \ \hline 1 & 1 & 0 & 1 \ \hline 1 & 1 & 1 & 0 \ \hline \end{tabular}

Q = \hrulefill

4 short_answer p. 8

The table shows part of the instruction set for a processor. The processor has one register, the Accumulator (ACC).

\begin{tabular}{|c|l|l|} \hline \multicolumn{2}{|c|}{\textbf{Instruction}} & \multicolumn{1}{c|}{\textbf{Explanation}} \ \cline{1-2} \textbf{Opcode} & \textbf{Operand} & \ \hline AND & #n / Bn / &n & Bitwise AND operation of the contents of the ACC with the operand \ \hline AND &

& Bitwise AND operation of the contents of the ACC with the contents of

\ \hline XOR & #n / Bn / &n & Bitwise XOR operation of the contents of the ACC with the operand \ \hline XOR &

& Bitwise XOR operation of the contents of the ACC with the contents of

\ \hline OR & #n / Bn / &n & Bitwise OR operation of the contents of the ACC with the operand \ \hline OR &

& Bitwise OR operation of the contents of the ACC with the contents of

\ \hline LSL & #n & Bits in ACC are shifted logically n places to the left. Zeros are introduced on the right-hand end. \ \hline LSR & #n & Bits in ACC are shifted logically n places to the right. Zeros are introduced on the left-hand end. \ \hline \end{tabular}

\begin{itemize} \item

can be an absolute or symbolic address \item # denotes a denary number, e.g. #127 \item B denotes a binary number, e.g. B10010001 \item & denotes a hexadecimal number, e.g. &4A \end{itemize}

4a 1 mark short_answer p. 8 4.3

The ACC currently contains the following positive binary integer:

\begin{tabular}{|c|c|c|c|c|c|c|c|} \hline 0 & 0 & 0 & 1 & 1 & 1 & 1 & 0 \ \hline \end{tabular}

Write a bit manipulation instruction that uses a binary shift to change the contents of the ACC to:

\begin{tabular}{|c|c|c|c|c|c|c|c|} \hline 0 & 1 & 1 & 1 & 1 & 0 & 0 & 0 \ \hline \end{tabular}

Instruction \hrulefill \hfill

4b 1 mark short_answer p. 9 4.3

The ACC currently contains the following positive binary integer:

\begin{tabular}{|c|c|c|c|c|c|c|c|} \hline 1 & 1 & 1 & 0 & 0 & 0 & 1 & 1 \ \hline \end{tabular}

Write the contents of the ACC after the instruction \texttt{XOR &12} is carried out.

\framebox{$\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square$}

4c 1 mark short_answer p. 9 4.3

The ACC currently contains the following positive binary integer:

\begin{tabular}{|c|c|c|c|c|c|c|c|} \hline 1 & 1 & 1 & 0 & 0 & 0 & 1 & 1 \ \hline \end{tabular}

Write the contents of the ACC after the instruction \texttt{AND #63} is carried out.

\framebox{$\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square$}

4d 1 mark short_answer p. 9 4.2

The ACC currently contains the following positive binary integer:

\begin{tabular}{|c|c|c|c|c|c|c|c|} \hline 1 & 1 & 1 & 0 & 0 & 0 & 1 & 1 \ \hline \end{tabular}

The current contents of memory are:

\begin{tabular}{cc} \textbf{Address} & \textbf{Data} \ 98 & 00100100 \ 99 & 00110001 \ 100 & 00110011 \ 101 & 10100011 \ 102 & 10101100 \end{tabular}

Write the contents of the ACC after the instruction \texttt{OR 100} is carried out.

\framebox{$\square\,\square\,\square\,\square\,\square\,\square\,\square\,\square$}

5 short_answer p. 10

The Operating System (OS) is responsible for hardware and security management in a computer system.

5a short_answer p. 10

5ai 2 marks short_answer p. 10 5.1

State \textbf{two} tasks that are performed by hardware management.

\hrulefill
\hrulefill

5aii 2 marks short_answer p. 10 5.1

State \textbf{two} tasks that are performed by security management.

\hrulefill
\hrulefill

5b short_answer p. 10

5bi 2 marks short_answer p. 10 5.1

Describe \textbf{one} benefit of using library routines when developing software.

5bii 2 marks short_answer p. 10 5.1

Describe \textbf{one} drawback of using library routines when developing software.

5c 2 marks short_answer p. 10 5.2

Identify \textbf{two} presentation features found in a typical Integrated Development Environment (IDE).

\hrulefill
\hrulefill

6 short_answer p. 11

The processor uses several registers, including the Accumulator (ACC) and the Current Instruction Register (CIR).

6a 2 marks short_answer p. 11 4.1

Complete the table by describing the role of each register.

\begin{tabular}{|p{3cm}|p{10cm}|} \hline \textbf{Register} & \textbf{Role} \ \hline ACC & \ & \ \hline CIR & \ & \ \hline \end{tabular}

6b 2 marks short_answer p. 11 4.1

Increasing the number of cores in a processor can affect the performance of a computer.

Describe the drawbacks of increasing the number of cores in a processor.

6c 3 marks short_answer p. 11 3.1

State \textbf{three} differences between Dynamic RAM (DRAM) and Static RAM (SRAM).

\hrulefill
\hrulefill
\hrulefill

7 short_answer p. 12

Web browsers use Internet Protocol (IP) addresses.

7a 2 marks short_answer p. 12 2.1

Complete the table by describing the following types of IP address.

\begin{tabular}{|c|p{10cm}|} \hline \textbf{Type of IP address} & \textbf{Description} \ \hline Static & \newline\newline \ \hline Public & \newline\newline \ \hline \end{tabular}

7b 2 marks short_answer p. 12 2.1

Consider the following IP address:

$$256.0.0.A$$

Circle whether this IP address is IPv4, IPv6 or an invalid IP address.

\begin{center} IPv4 \quad\quad IPv6 \quad\quad Invalid \end{center}

Justify your choice.

7c 4 marks long_answer p. 12 2.1

A user types a Uniform Resource Locator (URL) into the address bar of a web browser to access a web page.

Explain how the web browser uses the URL to access the web page.

7d short_answer p. 13

A bitmap file is downloaded. The image has a maximum of 256 colours and measures 512 pixels wide by 2048 pixels high.

7di 2 marks calculation p. 13 1.2

Calculate an estimate of the file size of the bitmap in kibibytes.

Show your working.

File size of bitmap \hrulefill kibibytes

7dii 2 marks short_answer p. 13 1.2

Explain why the actual file size may be larger than the one calculated in (d)(i).

7diii 2 marks short_answer p. 13 1.3

Explain how a bitmap image is compressed using run-length encoding (RLE).

8 short_answer p. 14

One ethical consideration for a student connecting their personal computer to the school network is the risk of spreading malware on the network.

8a 2 marks short_answer p. 14 6.1

Viruses and pharming are examples of malware.

Explain what is meant by a virus and pharming.

Virus \hrulefill

Pharming \hrulefill

8b 3 marks short_answer p. 14 7.1

Give \textbf{three} other ethical considerations for a student using their personal computer to connect to the school network.

\hrulefill
\hrulefill
\hrulefill

8c 4 marks long_answer p. 14 7.1

Describe \textbf{two} social impacts of students using Artificial Intelligence (AI) to complete their homework.

\hrulefill
\hrulefill

9 3 marks short_answer p. 15 3.1

Describe the differences between a monitoring system and a control system.

10 short_answer p. 15

An architect needs a model of a building.

10a 3 marks short_answer p. 15 3.1

Explain how the model will be printed using a 3D printer.

10b 1 mark short_answer p. 15 3.1

State why a 3D printer needs a buffer.

9618 Computer Science November 2025 Question Paper 11

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