Menu

Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 693 exam-style questions, each with its mark scheme and example answers. Print it, or answer it on paper and then open the mark schemes. Or browse the questions by topic.

Build a paper

Topics (none ticked: all of them)
Question types (none ticked: all of them)

Practice paper

4 questions · 11 marks

Pick again
Print
1Short recall1 markSecondary Memory Swap Remove

Data is stored on optical discs as pits and lands.

Name the component in an optical disc drive that reads this data.

[1 mark]
Mark scheme

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

Example answers and how they were marked
Full marks1/1

Laser

Why: Laser is the creditworthy answer (1).

No marks0/1

A read/write head

Why: Read/write head is not accepted by the mark scheme; it reads magnetic media, not optical discs, so no marks are awarded.

No marks0/1

Pits and lands

Why: Pits and lands are what the laser reads, not the component that reads the data, so the mark scheme does not accept them.

2Describe2 marksStored Program Computers Swap Remove

The control unit (CU) is a component inside the CPU.

Describe the role of the control unit in the fetch-decode-execute cycle.

[2 marks]
Mark scheme

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

  • Decodes each (fetched) instruction (1) to work out which operation is needed / which components should carry it out (1)
  • Coordinates/directs the other components (1) by sending control signals along the control bus (1)
  • Fetches the next instruction (1) by sending its address to main memory along the address bus (1)
  • Sends a read/write control signal to main memory (1) so that the instruction or data is transferred during the fetch/execute stage (1)

Do not accept answers about synchronising the CPU or timing the cycles (that is the role of the clock).

Do not accept answers about carrying out arithmetic or logical operations (that is the ALU).

Do not accept answers about holding data or the results of instructions (that is registers/main memory).

Do not accept generic answers that only say the CU controls the CPU or processes instructions, with no linked development.

Only award one mark for a response that only repeats that the CU sends control signals; the second mark needs a linked outcome such as coordination, a memory read/write, or fetching an instruction.

Do not accept 'during the decode stage' as the development for the decoding point, as it restates the question.

Example answers and how they were marked
Full marks2/2

It decodes the instruction that has been fetched so that it knows which operation the CPU must carry out and which components should do it.

Why: Decoding named with the acceptable wording 'each (fetched) instruction' (1), plus the linked development that this identifies the operation and components (1).

Some marks1/2

It decodes each instruction during the decode stage of the cycle.

Why: Earns (1) for decoding the instruction. 'During the decode stage' restates the question and is not accepted as a development, so the second mark is not earned.

No marks0/2

It carries out the calculations and comparisons when the instruction is executed.

Why: Calculations and comparisons are the ALU's role, which the 'Do not accept' line rules out, so no mark is earned.

3Explain2 marksPrimary Memory Swap Remove

RAM is used to store data while a computer is running.

Explain one reason why the data in RAM is lost when a computer is switched off.

[2 marks]
Mark scheme

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

  • RAM is volatile (memory) (1) because it needs a constant/continuous power supply to hold/store the data it contains (1)
  • Data is held in RAM as electrical states/charges (1) so when the power supply is removed these states cannot be kept/refreshed and the data is lost (1)
  • RAM is used as short-term storage for the data and instructions currently in use (1) because it can only hold them while the computer has power (1)

For both marks, the expansion must follow/associate with the statement and must link the loss of the data to the power supply being removed.

Accept 'RAM is volatile' on its own for the first mark; the second mark is only awarded for a linked reason about the power supply.

Do not accept 'RAM is temporary/short-term memory' or 'RAM is cleared when the computer is switched off' on its own for both marks, as neither gives a reason.

Do not accept answers that say the data is deleted/cleared/erased by the computer or the operating system, or that the data is saved/moved to secondary storage, without saying why the data cannot be kept (e.g. because RAM needs power/is volatile).

Example answers and how they were marked
Full marks2/2

RAM is volatile memory, which means it needs a constant power supply to keep the data it is holding. When the power is switched off, the data is lost.

Why: Linked point (1) for 'RAM is volatile memory' and reason (1) for needing a constant power supply to hold the data.

Some marks1/2

The data in RAM is lost because RAM is volatile memory.

Why: Point (1) for 'RAM is volatile' but no linked reason about the power supply, and the mark scheme states that 'RAM is volatile' alone earns only the first mark.

No marks0/2

The data is deleted from RAM by the operating system when the computer is shut down so that the memory is free for next time.

Why: No creditworthy point: the answer says the data is deleted without saying why it cannot be kept, which the mark scheme's 'Do not accept' line rules out.

4Discuss6 marksSecondary Memory Swap Remove

An independent film studio sells its films on discs. It also offers the same films as downloads. The studio is deciding whether to keep selling films on optical discs.

Discuss the use of optical storage for selling films.

Your answer should include:

  • how data is stored on optical media
  • the benefits of optical discs for selling films
  • the drawbacks of optical discs for selling films.

You do not need to consider other types of secondary storage.

[6 marks]
Mark scheme

Indicative content

How data is stored on optical media

  • Data is stored as pits and lands burnt or pressed into a spiral track on the disc.
  • A laser beam is shone at the disc and the light that is reflected back is measured; pits and lands reflect the light differently.
  • The differences in the reflected light are read as binary 1s and 0s.

Benefits of optical discs for selling films

  • Optical discs are cheap to mass produce once the master disc has been pressed, so the studio can sell each film at a low price.
  • A disc is small and light, so a customer can easily store it, carry it home or give it as a gift.
  • A Blu-ray disc can hold a whole high-definition film (up to 50 GB), so a customer can watch the film without an internet connection.
  • Artwork can be printed on the disc and its case, which helps the studio sell the film.

Drawbacks of optical discs for selling films

  • A DVD holds only about 8.4 GB, so a high-definition film with extra features may not fit on one and the studio would need to sell it on a Blu-ray instead.
  • Optical discs are easily scratched, which can cause read errors so the film will not play.
  • Many modern devices, such as some laptops, no longer have a disc drive, so some customers would not be able to play the film.
  • Discs can be affected by heat and sunlight, so they may deteriorate over time.

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 2 requires points to be linked or developed, for example a benefit or drawback explained in terms of the studio or its customers. An answer that only lists basic, independent points, with no linkage, is limited to Level 1.
  • Level 3 requires all three areas and a judgement about whether the studio should keep selling films on optical discs. Do not credit magnetic storage or solid state storage as a description of how optical media stores data; credit these only where they are compared with optical media.
Example answers and how they were marked
Full marks6/6

Optical media stores data as pits and lands burnt into a spiral track. A laser beam is shone at the disc and the reflected light is measured; pits and lands reflect it differently, and this pattern is read as binary 1s and 0s. Optical discs are cheap to mass produce, so the studio can sell each film at a low price, and a disc is small and light so a customer can store it or give it as a gift. A Blu-ray holds a whole high-definition film and can be played without an internet connection. However, a DVD may not hold a high-definition film with extra features, so the studio would need a Blu-ray, and discs are easily scratched, which can cause read errors so the film will not play. Many modern laptops have no disc drive, so some customers could not play the film. Overall the studio should keep selling discs as well as downloads, because the discs are cheap to produce and give customers a copy that works without an internet connection, even though some customers will prefer to download.

Why: Explains how data is stored on optical media using pits, lands, reflected light and binary (AO1); gives benefits applied to selling films (cheap mass production, portability, Blu-ray holds a film and plays offline) and drawbacks (DVD capacity, scratches causing read errors, no disc drive in modern laptops); ends with a sustained judgement and recommendation, so it meets the Level 3 guidance.

Some marks2/6

Optical storage uses a laser to read pits and lands. It is cheap to make discs, so the studio can sell them cheaply. Discs are portable. But they can be scratched and damaged. Some computers don't have a disc drive.

Why: Basic point about how data is stored, a laser reading pits and lands (1), plus basic points about benefits (cheap to produce, portable) and drawbacks (scratched, no disc drive), but the points are independent and undeveloped with no linkage or application to the studio, so it is the top of Level 1: 2 marks.

No marks0/6

Optical storage uses magnets to store data. The film studio should use optical discs because they are very fast and have a large capacity. They are not affected by scratches.

Why: No creditworthy points. Confuses optical storage with magnetic storage; claims it is fast, has a large capacity and is not affected by scratches, all of which are incorrect. Level 0.

Questions by topic

More ways to revise Edexcel GCSE Computer Science (1CP2)

Teachers: build a paper, print it with the mark schemes at the end, and sign your school up to set your classes activities on every topic.

Fetch Decode Explain isn't affiliated with or endorsed by Pearson Edexcel.