Edexcel GCSE Computer Science (1CP2) Exam Questions

• A They are lost (1)
• The only correct answer is A. The correct answer is They are lost
• B is not correct because RAM is volatile and its contents are lost when the power is switched off, so they are not stored permanently
• C is not correct because RAM is volatile and its contents are lost when the power is switched off, so they are not saved to secondary storage
• D is not correct because ROM is read-only memory that holds the start-up instructions, so the contents of RAM are not written to it

• A Blu-ray Disc (1)
• The only correct answer is A. The correct answer is Blu-ray Disc.
• B is not correct because a CD stores less data than a Blu-ray Disc, up to about 700 MB
• C is not correct because a DVD stores less data than a Blu-ray Disc, up to about 4.7 GB (single-layer) or 8.4 GB (dual-layer)
• D is not correct because magnetic tape is not an optical storage medium

Award one mark for any of the following up to a maximum of two marks:

• The program instructions and data are stored together in main memory/RAM (1)
• The same memory is used for both instructions and data (1)
• The instructions are fetched from main memory and executed by the CPU (1)
• The instructions are fetched and executed one at a time / in sequence (1)
• The program can be changed/replaced by loading new instructions into memory, without changing the hardware (1)

Do not accept the program is stored in secondary storage / on the hard disk.

Do not accept the program is stored in the CPU / in registers.

Award one mark for:

• Laser (1)

Allow laser beam

Do not accept read/write head

Do not accept pits

Do not accept lands

Do not accept reflective surface

Do not accept magnet/magnetic

Award up to two marks for a linked description such as:

• Stores programs (including the operating system) and data that are not currently in use (1) so that they can be loaded into RAM/main memory when needed (1)
• Keeps files/programs/data when the power is turned off (1) which happens because it is non-volatile (1)
• Stores files/data for backup or archiving (1) so that they can be recovered if the originals are lost/corrupted (1)

A correct role on its own earns one mark; the second mark requires a linked development.

Accept either order if both the role and the link are given.

Do not accept 'it is non-volatile' on its own, unless it is linked to keeping data when the power is turned off.

Do not accept answers that only name a storage type (magnetic, optical, solid state) without describing a role.

Do not accept responses that describe primary storage/RAM, e.g. storing the data/instructions the CPU is currently working on, or that secondary storage makes the computer run faster.

Award up to two marks for a linked description such as:

• A read/write head moves over the surface of the disk (1) to read/write data by detecting or changing the magnetic alignment of areas of the surface (1)
• The head magnetises areas of the disk surface in different directions (1) so each area represents a binary 1 or 0 (1)
• Data is stored on concentric circles called tracks (1) which are divided into sectors (1)

Allow one mark for tracks/concentric circles on their own.

For the second mark in the first two bullets, the response must refer to the magnetic alignment/charge being detected or changed, not just that the head reads/writes data.

Do not award a mark for 'it is magnetic' or 'it stores data in binary' with no description of how the data is stored.

Do not accept descriptions of optical storage (e.g. a laser, pits and lands) or solid state storage (e.g. electric charges in chips).

Award up to two marks for a linked explanation such as:

• (The ECU) is more reliable/less likely to crash (1) because it only runs the one program/has a single purpose (1)
• (The ECU) cannot be affected by other software/viruses (1) because it cannot run other software/it can only run the program it was made for (1)
• (The ECU) is cheaper (1) because it has limited processing resources/less memory/simple components (1)
• (The ECU) uses less power (1) because it has limited processing resources/a simpler processor (1)
• (The ECU) is smaller (1) because it has fewer components/less memory than a general purpose computer (1)

For both marks, the expansion must follow/associate with the statement.

A suitable benefit stated on its own earns one mark.

Do not accept a description or a location given as the reason, e.g. 'because it is part of the car', 'because it is inside the engine', 'because it is embedded'.

Do not accept a description of an embedded system on its own as the benefit, e.g. 'it does one specific job' or 'it is part of the car'.

Do not accept 'it is faster'/'it has a more powerful processor' as embedded systems have limited processing resources.

Indicative content

What embedded systems are used for in the drone

• An embedded system is a computer built into a larger device that performs a single, dedicated function as part of that device.
• The drone contains several embedded systems, and each one is dedicated to a task such as flight control, navigation, obstacle detection or battery monitoring rather than being a general-purpose computer.
• The flight controller embedded system processes data from the drone's sensors and changes the signals sent to the rotors, so the drone stays stable and can be steered while carrying a parcel.
• The GPS receiver embedded system works out the drone's position and uses it to navigate along the route to the customer's address.
• The camera embedded system captures images or video that are processed to detect obstacles, such as trees, buildings or overhead cables, in the drone's path.
• Sensor embedded systems, for example ultrasonic or infrared sensors, measure the distance to the ground and to obstacles so the drone can land and avoid collisions.
• The battery management and communication embedded systems monitor the charge and send the drone's status and location to the control centre, and the rotor-control embedded systems drive the rotors so the drone can take off, hover and land.

Benefits of using embedded systems in the drone

• Embedded systems use little power, so the drone can fly for longer and deliver more parcels on one charge.
• They are small and light, which is important because a heavier drone needs more power to stay in the air.
• Because each embedded system is dedicated to one task, it can respond quickly and reliably, so the drone can change direction in time to avoid an obstacle.
• Combining the processor, memory and input/output in one unit reduces the number of separate components and the cost per drone, so a fleet of delivery drones is cheaper to build.
• Embedded systems allow the drone to fly autonomously, so the company does not need a human pilot for every delivery.
• Programs are held in ROM, so the drone's behaviour is consistent and predictable each time it flies.

Any drawbacks or limitations of using embedded systems in the drone

• Each embedded system has limited processing power, so the drone may not be able to run complex obstacle-recognition software and could fail to identify an unusual obstacle.
• They have limited storage and RAM, so the drone cannot store much flight data or video on board and must send it to the control centre.
• The software is held in ROM and is difficult to update, so fixing a bug or adding a new feature may mean returning the drone or connecting it to a computer.
• The embedded systems are dedicated to the drone, so they cannot easily be reused for a different task if the drone is retired.
• If an embedded system fails, the drone may crash, which could injure people or damage property, so robustness is essential.
• A general-purpose computer would be too large and heavy for the drone, so the drone has to use these limited dedicated systems and cannot run general-purpose software.

Levels

• Level 0 (0 marks): No rewardable content.
• Level 1 (1–2 marks): Basic, independent points are made, showing elements of understanding of key concepts/principles of computer science. (AO1) The discussion will contain basic information with little linkage between points made or application to the context. (AO2)
• Level 2 (3–4 marks): Demonstrates adequate understanding of key concepts/principles of computer science. (AO1) The discussion shows some linkages and lines of reasoning with some structure and application to the context. (AO2)
• Level 3 (5–6 marks): Demonstrates comprehensive understanding of key concepts/principles of computer science to support the discussion being presented. (AO1) The discussion is well developed, with sustained lines of reasoning that are coherent and logically structured, and which clearly apply to the context. (AO2)

Additional guidance

• Level 3 responses must cover what embedded systems are used for in the drone and both benefits and drawbacks/limitations, with reasoning applied to the delivery drone. Do not accept general-purpose computer uses such as connecting to Wi-Fi to play videos, installing new software, apps or games, or using a server; do not accept the drone itself as a single embedded system unless a specific dedicated function is explained.
• A definition of an embedded system on its own, with no application to the drone, cannot lift an answer above Level 1; limited storage and inability to be repurposed must be linked to the drone, for example little flight data can be stored or the system cannot be reused for another task, to gain credit.