Menu

Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 604 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 · 8 marks

Pick again
Print
1Multiple choice1 markStored Program Computers Swap Remove

Identify the function of the control unit in the fetch-decode-execute cycle.

[1 mark]
  • ADecodes instructions
  • BPerforms arithmetic operations
  • CStores data and instructions
  • DTemporarily stores data being processed
Mark scheme
  • A Decodes instructions (1)
  • The only correct answer is A. The correct answer is Decodes instructions.
  • B is not correct because the arithmetic logic unit performs arithmetic operations
  • C is not correct because main memory stores data and instructions
  • D is not correct because registers temporarily store data being processed
Example answers and how they were marked
Full marks1/1

A Decodes instructions

Why: Correct option: the control unit decodes instructions during the fetch-decode-execute cycle (1).

No marks0/1

C Stores data and instructions

Why: Main memory stores data and instructions, not the control unit; this is a common distractor, so no mark.

No marks0/1

B Performs arithmetic operations

Why: Arithmetic operations are performed by the ALU, not the control unit; a common confusion between CPU components, so no mark.

2Short 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.

3Describe2 marksLow and High Level Languages Swap Remove

A programmer writes a program in a high-level language.

Describe why the program can be run on computers with different processors.

[2 marks]
Mark scheme

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

  • The same source code can be run on different types/makes of processor (1) with few or no changes being made to the program (1)
  • A compiler/interpreter is available for each type of processor (1) to translate the source code into the machine code for that processor (1)
  • The statements are not tied to one processor's instruction set (1) so the program is portable between different computers (1)

Do not accept 'it is translated by a compiler' on its own.

Do not accept 'the program does not need to be translated' or 'it is easier to use'.

Example answers and how they were marked
Full marks2/2

A compiler exists for each type of processor (1) to translate the source code into the machine code for that processor (1).

Why: Names the translator for each processor (1) and links it to producing that processor's machine code (1).

Some marks1/2

The same program can be run on different computers.

Why: States that the same code runs on different machines (1) but does not develop it by saying that few or no changes are needed.

No marks0/2

Because it is translated by a compiler.

Why: A compiler on its own does not explain machine independence; the answer does not say that a translator exists for each type of processor.

4Calculate2 marksAdding Binary Numbers Swap Remove

Binary patterns can represent numbers.

Complete the table to show the result of the 8-bit binary addition.

[2 marks]
1286432168421
10010110
01011100
Mark scheme

Award one mark for each correct nibble in the correct order:

  • 1111 (1)
  • 0010 (1)

0 marks if the response is not 8-bit binary.

Example answers and how they were marked
Full marks2/2

1111 0010

Why: 150 + 92 = 242, carrying where a column adds to 2: both nibbles are correct (2).

Some marks1/2

1111 0011

Why: A slip in the last bit. The first nibble is correct (1); the second is not.

No marks0/2

1101 1110

Why: Writes 1 in every column with a 1 and never carries. Neither nibble is correct.

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.