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 · 7 marks

Pick again
Print
1Multiple choice1 markPrimary Memory Swap Remove

Identify what is fetched from RAM during the fetch stage.

[1 mark]
  • AThe next instruction
  • BThe data at a memory address
  • CThe decoded instruction
  • DThe address of the next instruction
Mark scheme
  • A The next instruction (1)
  • The only correct answer is A. The correct answer is the next instruction.
  • B is not correct because data is fetched during the execute stage
  • C is not correct because an instruction is decoded after it is fetched
  • D is not correct because the program counter holds the address used to fetch the instruction
Example answers and how they were marked
Full marks1/1

A The next instruction

Why: The next instruction is fetched from RAM during the fetch stage (1).

No marks0/1

B The data at a memory address

Why: Near miss: data is not fetched during the fetch stage; data is used during the execute stage.

No marks0/1

C The decoded instruction

Why: Misconception: an instruction is decoded after it is fetched, in the decode stage.

2Short recall2 marksSecondary Memory Swap Remove

Computers have both primary storage and secondary storage.

Define the term secondary storage.

[2 marks]
Mark scheme

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

  • (Storage that is) non-volatile / keeps its data when the power is turned off (1)
  • (Storage that is) used to store programs and data/files (for later use) (1)
  • (Storage that is) not directly accessible by the CPU / not directly accessed by the CPU (1)

Allow both the non-volatile point and the stores programs and data point from one sentence if each idea is clearly stated, e.g. 'non-volatile storage that holds programs and data'.

Allow accessed via the CPU / must be copied into RAM before the CPU can use it for the third point.

Do not accept volatile / loses its data when the power is turned off.

Do not accept a description of primary storage, such as RAM or ROM.

Do not accept capacity.

Do not accept an example device on its own (e.g. hard disk drive).

Example answers and how they were marked
Full marks2/2

Secondary storage is non-volatile, so it does not lose data when the power is turned off. It is used to store programs and data files for later use.

Why: Non-volatile / keeps data when the power is off (1) and used to store programs and data files (1), each idea clearly stated.

Some marks1/2

Secondary storage is used to store programs and data files.

Why: Stores programs and data/files (1), but nothing is said about it being non-volatile or not directly accessible by the CPU.

No marks0/2

Secondary storage is volatile memory that holds the data the CPU is using at the moment.

Why: Describes primary storage (RAM) and says it is volatile, which the mark scheme says not to accept, so no marks are awarded.

3Describe2 marksSecondary Memory Swap Remove

A computer uses a magnetic hard disk.

Describe how data is stored on a magnetic hard disk.

[2 marks]
Mark scheme

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).

Example answers and how they were marked
Full marks2/2

The read/write head moves over the magnetic surface and magnetises areas of the disk to store the 1s and 0s.

Why: Head moves over the surface (1) and magnetises areas to represent 1s and 0s (1).

Some marks1/2

The data is stored on tracks on the disk.

Why: Tracks/concentric circles (1), but no development such as tracks divided into sectors.

No marks0/2

It is magnetic and saves the data in 1s and 0s.

Why: Near-miss: 'magnetic' alone and 'data in binary/1s and 0s' with no description of how data is stored, which the mark scheme does not award.

4Describe2 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.

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.