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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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3 questions · 5 marks

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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.

2Describe2 marksLow and High Level Languages Swap Remove

A device driver is software that allows the operating system to control a piece of hardware. Device drivers are often written in a low-level programming language.

Describe one reason why a low-level programming language is suitable for writing a device driver.

[2 marks]
Mark scheme

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

  • Instructions can manipulate/control the hardware/memory/registers directly (1) so the driver can control the specific device it is written for (1)
  • The code is written for one specific processor/architecture (1) so it works with the exact hardware it will control (1)
  • The programmer controls exactly how memory/registers are used (1) so the code is efficient and needs little memory, which suits a device that has limited memory (1)
  • Each instruction maps to one machine code instruction (1) so the driver code is small enough to fit in the memory of the device (1)

Extra detail, such as naming the device the driver controls, is not needed to earn the marks.

Do not accept 'it is closer to machine code' on its own: it must be developed to show how this helps the driver, e.g. it can control the hardware directly.

Do not accept 'it is faster/quicker' with no link to the hardware/device, e.g. the device responds quickly.

Do not accept 'it is easier to learn', 'it is easier to debug' or 'it takes less time to write'.

Example answers and how they were marked
Full marks2/2

Low-level instructions can manipulate the hardware and memory directly (1) so the driver can control the specific device it was written for, such as a sound card (1).

Why: Point about direct control of hardware/memory (1) linked to controlling the specific device (1). The named device is extra detail and is not needed.

Some marks1/2

Low-level instructions can manipulate the hardware directly.

Why: Correct point (1) but no linked development saying how this helps the device driver.

No marks0/2

It is closer to machine code so it runs faster than a high-level language.

Why: 'Closer to machine code' is not developed into how this helps the driver, and 'runs faster' is not linked to the hardware/device, so no mark.

3Explain2 marksWired Connections Swap Remove

A school connects its computers to the network using copper Ethernet cables.

A computer in a new classroom is 150 metres from the network switch. It is connected using a copper Ethernet cable, but the connection is unreliable.

Explain why the connection is unreliable.

[2 marks]
Mark scheme

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

  • A copper Ethernet cable has a standard maximum segment length of 100 metres (1) so over 150 metres the signal is too weak to be read correctly (1)
  • 150 metres is beyond the maximum range of a copper Ethernet cable (1) so the computer does not receive the data with enough signal strength (1)
  • The signal weakens/degrades as it travels along the cable (1) so at 150 metres the data is corrupted/lost (1)

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

Do not accept 'the cable is too long' on its own without saying that the signal weakens/does not reach the computer with enough strength.

Do not accept 'the signal is lost/weak' on its own without linking it to the distance being beyond the maximum range of copper cable.

Do not accept answers that only blame interference from walls or other devices, as the problem here is the distance.

Example answers and how they were marked
Full marks2/2

A copper Ethernet cable has a standard maximum segment length of 100 metres. The classroom is 150 metres away, so the signal has become too weak to be read correctly, which makes the connection unreliable.

Why: States the cable is beyond its maximum range (1) and links this to the signal being too weak to be read (1).

Some marks1/2

Copper Ethernet cables can only carry data for 100 metres, which is less than 150 metres.

Why: Identifies that the cable run is beyond the maximum range (1) but does not say what happens to the signal as a result.

No marks0/2

There is interference from the walls of the classroom, which slows the signal down.

Why: Blames interference rather than distance, so there is no creditworthy point about range; the mark scheme does not accept interference as the explanation here.

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