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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.

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4 questions · 6 marks

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1Multiple choice1 markStored Program Computers Swap Remove

Identify the bus that carries addresses in one direction only, from the CPU to main memory.

[1 mark]
  • AAddress bus
  • BControl bus
  • CData bus
  • DSystem bus
Mark scheme
  • A Address bus (1)
  • The only correct answer is A. The correct answer is address bus. Do not accept 'address' on its own.
  • B is not correct because the control bus carries control signals in both directions between the CPU and other components
  • C is not correct because the data bus carries data in both directions between the CPU and main memory
  • D is not correct because the system bus is the collection of all three buses
Example answers and how they were marked
Full marks1/1

A Address bus

Why: Correct option: the address bus carries addresses in one direction only, from the CPU to main memory (1).

No marks0/1

C Data bus

Why: The data bus carries data in both directions, so it is not the bus that carries addresses in one direction only from the CPU to main memory; no creditworthy point.

No marks0/1

B Control bus

Why: The control bus carries control signals in both directions, not addresses in one direction only; this is the common control/address bus confusion, so no mark.

2Multiple choice1 markCharacter Sets Swap Remove

ASCII is a character set used for representing text.

Identify the number of bits used to encode each character in ASCII.

[1 mark]
  • A6
  • B7
  • C8
  • D16
Mark scheme
  • B 7 (1)
  • The only correct answer is B. The correct answer is 7 bits.
  • A is not correct because 6 bits give only 64 different characters
  • C is not correct because 8 bits are used by extended ASCII to give 256 characters
  • D is not correct because 16 bits give 65 536 different characters, which is far more than the 128 in ASCII
Example answers and how they were marked
Full marks1/1

B 7

Why: B is the only correct answer: each ASCII character is encoded using 7 bits (1).

No marks0/1

C 8

Why: Near miss scoring 0: 8 bits is extended ASCII, and the scheme's C line says extended ASCII, not ASCII, is not the answer.

No marks0/1

A 6

Why: Misconception scoring 0: 6 bits give only 64 different characters, so it cannot be ASCII.

3Short recall2 marksCompression Swap Remove

Images and sound can be stored using lossy compression.

Define the term lossy compression.

[2 marks]
Mark scheme

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

  • Reduces the size of a file (1)
  • Permanently removes/loses some data (1)
  • The original file cannot be recreated/restored exactly (1)

Allow 'some data is deleted/discarded and cannot be recovered' for the second mark.

Do not award the first mark where the response also states that no data is lost.

Do not accept 'removes repeated data' (this describes lossless compression).

Example answers and how they were marked
Full marks2/2

Lossy compression reduces the size of a file by permanently removing some data, so the original cannot be restored exactly.

Why: Reduces the size of a file (1); permanently removes some data (1); maximum two marks awarded.

Some marks1/2

It makes a file smaller.

Why: Reduces the size of a file (1); no reference to data being permanently lost.

No marks0/2

It makes a file smaller without losing any of the data.

Why: States that no data is lost, which describes lossless compression; the first mark is not awarded.

4Describe2 marksMemory Management Swap Remove

A program is stored on secondary storage before it is run.

Describe how the operating system manages memory when a program is started.

[2 marks]
Mark scheme

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

  • The program (and its data) is copied/loaded from secondary storage into main memory/RAM (1) so that the CPU can fetch/execute its instructions (1)
  • An area of main memory is allocated/reserved for the program (1) that is large enough to hold the program and its data (1)
  • The operating system checks that there is enough free main memory (1) before the program can be started/loaded, otherwise it cannot run/an error is reported (1)
  • The operating system keeps a record of the memory addresses used by the program (1) so that its instructions and data can be found when it runs (1)

Allow 'loaded into RAM', 'stored in memory' and 'put into main memory' as equivalent to copied into main memory.

A single statement that the program is loaded/stored in main memory, with no linked development, can be given one mark only.

Do not accept descriptions of the CPU fetching/executing instructions that do not refer to the operating system loading or allocating memory.

Do not accept responses about virtual memory (moving processes to secondary storage) or about which process runs next on the CPU.

Do not accept the program being run from secondary storage/hard disk.

Example answers and how they were marked
Full marks2/2

The operating system copies the program and its data from secondary storage into main memory so that the CPU can fetch and execute its instructions.

Why: Copying the program and data into main memory (1) linked to the CPU fetching/executing instructions (1).

Some marks1/2

The operating system loads the program into main memory.

Why: The program is copied/loaded into main memory (1), but there is no linked development of how or what this leads to, so only one mark is given.

No marks0/2

The CPU fetches the program's instructions from main memory and executes them one at a time.

Why: This describes the fetch-decode-execute cycle, not the operating system loading or allocating memory, which is the Do not accept line; no creditworthy point is made.

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