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

3 questions · 7 marks

Pick again
Print
1Short recall3 marksStored Program Computers Swap Remove

The CPU contains several components.

Name three components of the CPU.

[3 marks]
Mark scheme

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

  • Control unit / CU (1)
  • Arithmetic logic unit / ALU (1)
  • Register(s) (1)
  • Clock (1)

Do not accept main memory / RAM.

Do not accept cache.

Marks can be awarded in any order.

Example answers and how they were marked
Full marks3/3

Control unit, arithmetic logic unit and registers.

Why: Names three creditworthy CPU components (control unit, ALU, registers), one mark each.

Some marks2/3

Control unit, clock and main memory.

Why: Control unit (1) and clock (1) are creditworthy; main memory is not a component of the CPU, a common misconception seen in the June 2023 question.

No marks0/3

Main memory, RAM and cache.

Why: None are CPU components named in the specification; candidates often confuse main memory with CPU components.

2Describe2 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.

3Explain2 marksStored Program Computers Swap Remove

Computers use the von Neumann stored program concept.

Explain one benefit of storing program instructions in main memory.

[2 marks]
Mark scheme

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

  • A new program can be loaded/changed without rewiring/reconfiguring the computer (1) because the instructions are held in main memory and can be replaced (by loading a different program) (1)
  • Different programs can be run on the same computer (1) because the program instructions are stored in RAM/main memory (1)
  • The CPU can fetch instructions automatically (1) so an operator is not needed to enter each instruction by hand (1)
  • Instructions can be stored and run in sequence (1) because the CPU reads the next instruction from main memory (1)

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

Allow a benefit stated as an example, e.g. a program can be run as soon as it is loaded (1), with a linked reason (1)

Do not accept a statement that only describes storing or loading, e.g. 'programs can be loaded into memory', without a benefit and a linked reason.

Do not accept 'it is faster' / RAM is quicker to access than secondary storage / RAM is closer to the CPU (1 for nothing): this describes the speed of RAM, not a benefit of storing program instructions in main memory.

Do not accept answers about secondary storage holding programs, e.g. 'the program is kept on the hard drive when the computer is turned off', as this is a property of secondary storage, not of the stored program concept.

Ignore references to the fetch-decode-execute cycle that are not linked to a benefit.

Example answers and how they were marked
Full marks2/2

A new program can be loaded without changing the hardware because the instructions are held in main memory and can be replaced

Why: Linked benefit (1) and linked reason (1), matching the first mark scheme line.

Some marks1/2

Different programs can be run on the same computer.

Why: Valid benefit stated (1) but no linked reason is given, so the second mark is not awarded.

No marks0/2

It is faster because RAM is closer to the CPU.

Why: A speed answer about RAM, which the mark scheme's 'Do not accept' line rules out, so no creditworthy point and no linked reason.

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.