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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.

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4 questions · 7 marks

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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.

2Short recall2 marksStored Program Computers Swap Remove

Computers use the von Neumann stored program concept.

Define the term stored program concept.

[2 marks]
Mark scheme

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

  • Program instructions are stored in main memory/RAM (1)
  • The data used by the program is stored in main memory/RAM (1)
  • The CPU fetches/reads instructions from main memory to execute them (1)
  • The program can be run without the instructions being input again (1)

Allow 'the program is stored in memory' for one mark.

Do not accept answers about programs being stored on secondary storage, such as a hard disk or USB memory stick.

Do not accept answers that only describe the von Neumann architecture (e.g. having a CPU and memory) without stating that instructions are stored in main memory.

Example answers and how they were marked
Full marks2/2

Both the program instructions and the data the program uses are held in the same main memory, and the CPU fetches these instructions from memory to execute them.

Why: Instructions stored in main memory (1) and the CPU fetches instructions from memory to execute them (1).

Some marks1/2

Program instructions are stored in main memory.

Why: Instructions stored in main memory (1). No second point about data being stored in the same memory or about the CPU fetching instructions.

No marks0/2

The program is saved on the hard disk so that it can be loaded into RAM when the user runs it.

Why: A near-miss about secondary storage, which the mark scheme says not to accept; the stored program concept is about instructions being held in main memory.

3Describe2 marksStored Program Computers Swap Remove

A computer is based on the von Neumann stored program concept.

Describe how the CPU uses main memory (RAM) during the fetch-decode-execute cycle.

[2 marks]
Mark scheme

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

  • The program's instructions (and the data it uses) are held in main memory/RAM (1) so the CPU fetches both the instructions and the data from that one memory (1)
  • The CPU fetches the next instruction from main memory/RAM (1) using the address of the memory location that holds it (1)
  • The CPU reads/fetches data from main memory/RAM (1) when an instruction needs it and writes the result back to main memory/RAM (1)
  • The program's instructions are held in main memory/RAM while the program runs (1) and the CPU fetches them one at a time/one after another to be decoded and executed (1)

Allow 'memory' for main memory/RAM.

Allow 'gets' for fetches/reads.

For both marks, the development must say what the CPU does with the contents of main memory (fetches/reads/writes), not just that main memory is used.

Do not accept answers about the program being stored in secondary storage, such as on a hard drive, or about it being loaded from there.

Do not accept benefits such as the computer running faster or being easier for the user.

Do not accept naming CPU components (control unit, arithmetic logic unit, registers) or buses on their own, without saying what is stored or fetched.

Do not accept 'the computer stores data' on its own, without a link to the instructions of a program.

Example answers and how they were marked
Full marks2/2

The program's instructions and the data it uses are both held in the same main memory (RAM), so the CPU can fetch the instructions and the data it needs from that one memory.

Why: Linked point (1) that instructions and data are stored together in main memory, with the development (1) that the CPU fetches both from the same memory.

Some marks1/2

The CPU fetches the instructions from main memory so that they are processed more quickly.

Why: The first point earns (1) for the CPU fetching instructions from main memory. The second statement is a benefit (speed), which the 'Do not accept benefits' line rules out, so it earns nothing.

No marks0/2

The control unit decodes each instruction and the ALU carries out the calculations.

Why: Both statements name CPU components without saying what is stored, fetched or written, which the mark scheme tells examiners not to accept, so neither earns a mark.

4Explain2 marksSecondary Memory Swap Remove

A Blu-ray disc and a CD are the same physical size.

Explain why a Blu-ray disc can store more data than a CD.

[2 marks]
Mark scheme

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

  • The pits and lands on a Blu-ray disc are smaller/closer together (1) because the blue laser has a shorter wavelength than the infrared laser used by a CD (1)
  • More pits and lands can be stored in the same length of track (1) because the blue laser has a shorter wavelength, so it can focus on a smaller area/read smaller details (1)
  • A blue laser can focus on a smaller area (1) so smaller pits and lands can be used, allowing more data to be stored on the disc (1)

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

Do not accept 'a Blu-ray is newer/better' or 'a Blu-ray has more space/bigger storage' without a linked reason about the laser/pits and lands.

Do not accept answers about read/write speed, for example 'a Blu-ray spins faster', because the question asks about the amount of data stored, not how quickly it is read.

Do not award 'a Blu-ray disc can have more layers' on its own as the reason; it must be linked to the smaller pits and lands/shorter wavelength of the laser.

Do not accept 'red laser' for a CD; a CD uses an infrared laser (red is used by DVD).

Example answers and how they were marked
Full marks2/2

A Blu-ray is read with a blue laser which has a shorter wavelength so the pits and lands on the disc can be smaller and more of them fit on the disc.

Why: Linked point (1) shorter wavelength of the blue laser with reason (1) smaller pits and lands so more data fits on the same disc.

Some marks1/2

The pits and lands on a Blu-ray are smaller than the ones on a CD so it can store more data.

Why: Point (1) that the pits and lands are smaller, but the second part repeats the question and does not give the linked reason (shorter wavelength of the blue laser/infrared CD laser), so only one mark.

No marks0/2

A Blu-ray spins faster than a CD so more data can be read from it in the same time.

Why: Do not accept answers about read/write speed; the question asks about the amount of data stored, not how quickly it is read.

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