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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 573 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 markFetch Decode Execute Cycle Swap Remove

Identify the bus that carries memory addresses from the CPU to main memory. (1)

[1 mark]
  • AAddress bus
  • BControl bus
  • CData bus
  • DProgram counter
Mark scheme
  • A Address bus (1)
  • The only correct answer is A. The correct answer is address bus.
  • B is not correct because the control bus carries control signals
  • C is not correct because the data bus carries data and instructions
  • D is not correct because the program counter holds the address of the next instruction, it does not carry addresses
Example answers and how they were marked
Full marks1/1

A Address bus

Why: Correct option: the address bus carries memory addresses from the CPU to main memory (1).

No marks0/1

C Data bus

Why: Near-miss distractor: the data bus carries data and instructions between the CPU and main memory, not memory addresses (0).

No marks0/1

D Program counter

Why: Misconception: the program counter is a register that holds the address of the next instruction, it does not carry addresses to main memory (0).

2Multiple choice1 markSound Swap Remove

A sound wave is sampled and the amplitude of each sample is stored using 2 bits.

Identify the number of different amplitude values that can be stored for each sample.

[1 mark]
  • A2
  • B4
  • C8
  • D16
Mark scheme
  • B 4 (1)
  • The only correct answer is B. The correct answer is 4 (2 bits give 2^2 = 4 values).
  • A is not correct because 2 is the number of bits used to store each sample
  • C is not correct because 8 different amplitude values would need 3 bits
  • D is not correct because 16 different amplitude values would need 4 bits
Example answers and how they were marked
Full marks1/1

B 4

Why: Selects the only correct option (1).

No marks0/1

C 8

Why: Near miss: 8 values would need 3 bits, one more than this recording uses (0).

No marks0/1

A 2

Why: Typical misconception: 2 is the number of bits, not the number of amplitude values those bits can store (0).

3Describe2 marksUtility Software Swap Remove

A hard disk can become fragmented as files are saved and deleted.

Describe how disk defragmentation software improves the performance of a hard disk.

[2 marks]
Mark scheme

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

  • Parts of a file are moved so they are stored together/in consecutive locations (1) so the read/write head has less distance to travel to read the file (1)
  • Files are rearranged so that each file is stored in one block (1) which reduces the time taken to open/load the file (1)
  • Free space on the disk is collected into one area (1) so new files can be saved without becoming fragmented (1)
  • The parts of each fragmented file are put in order (1) so fewer movements of the read/write head are needed to read it (1)

Do not accept responses about compressing files, deleting files or increasing the amount of storage, as these are not what defragmentation software does.

Do not accept 'it makes the disk faster' without saying how the files are changed.

Example answers and how they were marked
Full marks2/2

It moves the parts of a file so they are stored together in consecutive locations (1), so the read/write head does not have to move as far and the file opens more quickly (1).

Why: Linked point (1) and development (1): the file parts are stored together, which reduces read/write head movement.

Some marks1/2

It reorganises the files on the hard disk so that they are stored together.

Why: The point is made (1) but there is no development saying how this improves performance, so the second mark is not awarded.

No marks0/2

It compresses the files so that they take up less space on the disk.

Why: This describes data compression software, which the mark scheme says is not accepted; no creditworthy point is made.

4Describe2 marksTranslators Swap Remove

High-level code can be translated by a compiler or by an interpreter.

Describe how a compiler translates high-level code differently from an interpreter.

[2 marks]
Mark scheme

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

  • The compiler translates the whole program/complete source code in one go (1) whereas the interpreter translates one line/statement at a time (1)
  • The compiler translates all of the source code before any of it is run/executed (1) but the interpreter translates each line/statement as it reads it (1)
  • The interpreter translates one line/statement at a time (1) and the compiler translates the whole program/source code together (1)

Accept the compiler point and the interpreter point in either order.

Do not accept responses about object code/executable files, when the translated code is executed, how errors are reported, or speed/memory use.

Do not accept 'the interpreter executes/runs each line' on its own, without saying that it translates one line/statement at a time.

Example answers and how they were marked
Full marks2/2

A compiler translates the whole program in one go, while an interpreter translates one line at a time.

Why: Whole program translated in one go (1) and interpreter translates one line at a time (1).

Some marks1/2

A compiler translates the whole program in one go.

Why: Whole program translated in one go (1); no linked point about the interpreter translating a line at a time.

No marks0/2

A compiler produces an executable file, but an interpreter does not.

Why: Describes the output, not the amount translated at a time; object code/executable files are not accepted.

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