Learn Extracted exam questions A-Level Computer Science 9618 Computer Science November 2024 Question paper 11
9618 Computer Science November 2024 Question paper 11
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State \textbf{one} difference between a tebibyte and a gigabyte.
Convert the unsigned binary integer into hexadecimal.
110001100111
Answer \hrulefill
Convert the two's complement binary number into denary.
100110010111
Answer \hrulefill
Convert the Binary Coded Decimal (BCD) into denary.
010101110011
Answer \hrulefill
Subtract the denary number 23 from the two's complement binary number 01001010
Perform this calculation using binary subtraction.
Show your working.
Answer \hrulefill
State one reason why binary addition and subtraction can result in overflow.
A shop repairs electronic devices, for example mobile phones and tablet computers. The shop owner stores the data about the repairs using a file-based approach.
Give \textbf{one} limitation of using a file-based approach to store the data \textbf{and} explain how a relational database addresses this limitation.
Limitation \hrulefill
Explanation \hrulefill
The shop owner creates a relational database called \texttt{FIXIT}.
The database stores data about the customers and the devices for repair.
Some devices need new parts that are ordered from suppliers.
The database \texttt{FIXIT} is designed to include the following tables:
\texttt{PART(PartID, Description, Price, SupplierID)}
\texttt{CUSTOMER(CustomerID, FirstName, LastName, ContactNumber)}
\texttt{REPAIR(RepairNumber, StartDate, EndDate, CustomerID, Device)}
\texttt{REPAIR_PART(PartID, RepairNumber, Quantity)}
Complete the entity-relationship (E-R) diagram for the given tables.
The table shows sample data for the table \texttt{REPAIR_PART}.
\begin{tabular}{|l|l|l|} \hline \multicolumn{1}{|c|}{\textbf{PartID}} & \multicolumn{1}{c|}{\textbf{RepairNumber}} & \multicolumn{1}{c|}{\textbf{Quantity}} \ \hline ACD128SA & 0022 & 3 \ \hline PPOR543DWW & 0022 & 1 \ \hline TR453 & 0023 & 1 \ \hline PPOR543DWW & 0023 & 2 \ \hline WED5 & 0024 & 5 \ \hline \end{tabular}
Write a Structured Query Language (SQL) script to define the table \texttt{REPAIR_PART}.
Include constraints (restrictions) on the data that can be entered into each field where appropriate.
Suppliers send invoices to the company for the parts that are used. A new table, \texttt{INVOICE}, stores the data about each invoice and whether it has been paid or not.
The design for the table \texttt{INVOICE} is shown:
\texttt{INVOICE(InvoiceID, SupplierID, AmountDue, Paid, DatePaid)}
The table shows sample data for the table \texttt{INVOICE}.
\begin{tabular}{|l|l|l|l|l|} \hline \textbf{InvoiceID} & \textbf{SupplierID} & \textbf{AmountDue} & \textbf{Paid} & \textbf{DatePaid} \ \hline 000001 & JK675 & 22.50 & TRUE & 01/01/2024 \ \hline 000002 & WR443 & 358.99 & FALSE & \ \hline 000003 & JK675 & 10.21 & FALSE & \ \hline \end{tabular}
Write an SQL script to return the total amount due to the supplier with the ID of JK675 for all the invoices that have not currently been paid.
Complete the table by writing a definition for each of the database terms.
\begin{tabular}{|c|p{10cm}|} \hline \textbf{Term} & \multicolumn{1}{c|}{\textbf{Definition}} \ \hline Referential integrity & \newline\newline \ \hline Candidate key & \newline\newline \ \hline Tuple & \newline\newline \ \hline \end{tabular}
A computer system has a dual-core Central Processing Unit (CPU).
State the purpose of the system clock and the Control Unit (CU) in a CPU.
System clock \hrulefill
CU \hrulefill
The number of cores in the processor affects the performance of the computer system.
Identify \textbf{one other} feature of a processor that can affect the performance of a computer system \textbf{and} state why it affects the performance.
Feature \hrulefill
Reason \hrulefill
A solid state (flash) memory drive is automatically recognised by the computer when it is plugged into a port in the computer.
Identify an appropriate type of port to connect the solid state memory drive to the computer.
Explain how this port provides an automatic connection.
Port \hrulefill
Explanation \hrulefill
Identify \textbf{two} disadvantages of using Dynamic RAM (DRAM) instead of Static RAM (SRAM) in a computer system.
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The computer system is used to store data received from a temperature sensor every five seconds. The data is stored on an optical disc using an optical disc reader/writer.
Describe the principal operation of an optical disc reader/writer.
The computer uses a buffer when writing data to the optical disc.
Explain the use of a buffer when writing data to the optical disc.
A student uses a laptop to write a program that is saved as a text file.
The laptop has utility software and an Operating System (OS).
Describe the file management tasks carried out by an OS.
Explain the need for back-up software.
The student compresses the file before it is emailed to their teacher as an attachment.
Explain the benefits to the teacher of the attachment being a compressed file.
Describe \textbf{one} lossless method of compressing a text file.
The student used a program library when writing their program.
Explain the benefits to the student of using library files when writing a program.
The program code is written using an Integrated Development Environment (IDE).
One presentation feature found in a typical IDE is prettyprint.
Identify and describe \textbf{one other} presentation feature found in a typical IDE.
Feature \hrulefill
Description \hrulefill
One debugging feature found in a typical IDE is single stepping.
Identify and describe \textbf{one other} debugging feature found in a typical IDE.
Feature \hrulefill
Description \hrulefill
A security system has both a floodlight (very bright light) and an audio alarm.
The data from multiple sensors is analysed and used to: \begin{itemize} \item turn on the floodlight \item sound the audio alarm. \end{itemize}
Sensors can be used to detect: \begin{itemize} \item if doors are open \item the external daylight level \item if people are detected within a set distance. \end{itemize}
Complete the table to identify the most appropriate type of sensor for each scenario.
\begin{tabular}{|p{8cm}|p{6cm}|} \hline \textbf{Scenario} & \textbf{Type of sensor} \ \hline A door is open. & \hrulefill \ \hline The external daylight level is below a set amount. & \hrulefill \ \hline A person is detected within 2 metres. & \hrulefill \ \hline \end{tabular}
The floodlight (\textbf{X}) and audio alarm (\textbf{Y}) operate according to the following criteria:
\begin{tabular}{|c|c|c|c|} \hline \textbf{Parameter} & \textbf{Description of parameter} & \textbf{Binary value} & \textbf{Condition} \ \hline \textbf{A} & external daylight level & 1 & Low \ \cline{3-4} & & 0 & High \ \hline \textbf{B} & front door & 1 & Open \ \cline{3-4} & & 0 & Closed \ \hline \textbf{C} & person is within 2 m & 1 & Detected \ \cline{3-4} & & 0 & Not detected \ \hline \textbf{D} & back door & 1 & Open \ \cline{3-4} & & 0 & Closed \ \hline \textbf{E} & security system & 1 & Switched on \ \cline{3-4} & & 0 & Switched off \ \hline \end{tabular}
The floodlight turns on ($X = 1$) if: \begin{itemize} \item the security system is switched on \textbf{and} \item the external daylight level is low \textbf{and} \item a person is detected within 2 m. \end{itemize}
The audio alarm turns on ($Y = 1$) if: \begin{itemize} \item the security system is switched on \textbf{and} \item one \textbf{or} more doors are open, \textbf{or} a person is detected within 2 m. \end{itemize}
Write logic expressions for the security system.
\textbf{X} = \hrulefill
\textbf{Y} = \hrulefill
Explain whether the security system is an example of a monitoring system or a control system.
A car park system uses a camera to record the registration number of each car as it enters and leaves the car park.
Explain how artificial intelligence is used in the car park system to identify the car's registration number.
Software is distributed with a licence.
Give \textbf{two} benefits of distributing software using a shareware software licence.
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- \hrulefill
Give \textbf{two} benefits of distributing software using a commercial software licence.
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A computer designed using the Von Neumann model for a computer system contains general purpose registers and special purpose registers.
Describe the purpose of the Status Register (SR).
Identify \textbf{two} differences between general purpose registers and special purpose registers.
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