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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 markCharacter Sets Swap Remove

Characters are encoded using 7-bit ASCII.

Identify the number of different characters that can be represented using 7-bit ASCII.

[1 mark]
  • A64
  • B127
  • C128
  • D256
Mark scheme
  • C 128 (1)
  • The only correct answer is C. The correct answer is 128.
  • A is not correct because 6 bits give only 64 different combinations
  • B is not correct because 127 is the largest 7-bit value, not the number of characters that 7 bits can represent
  • D is not correct because 256 characters need 8 bits, as used by 8-bit extended ASCII
Example answers and how they were marked
Full marks1/1

C 128

Why: Selects the only correct option (1): 7 bits give 2 to the power of 7, which is 128 different characters.

No marks0/1

D 256

Why: Near miss scoring 0: 256 is the number of characters that 8 bits give in extended ASCII, not 7-bit ASCII.

No marks0/1

B 127

Why: Misconception scoring 0, the off-by-one error the examiners' report describes: 127 is the largest 7-bit value, but 7 bits give 128 different characters.

2Short recall2 marksStored Program Computers Swap Remove

Computers use the von Neumann stored program concept.

Define the term stored program concept.

[2 marks]
Mark scheme

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

  • Program instructions are stored in main memory/RAM (1)
  • The data used by the program is stored in main memory/RAM (1)
  • The CPU fetches/reads instructions from main memory to execute them (1)
  • The program can be run without the instructions being input again (1)

Allow 'the program is stored in memory' for one mark.

Do not accept answers about programs being stored on secondary storage, such as a hard disk or USB memory stick.

Do not accept answers that only describe the von Neumann architecture (e.g. having a CPU and memory) without stating that instructions are stored in main memory.

Example answers and how they were marked
Full marks2/2

Both the program instructions and the data the program uses are held in the same main memory, and the CPU fetches these instructions from memory to execute them.

Why: Instructions stored in main memory (1) and the CPU fetches instructions from memory to execute them (1).

Some marks1/2

Program instructions are stored in main memory.

Why: Instructions stored in main memory (1). No second point about data being stored in the same memory or about the CPU fetching instructions.

No marks0/2

The program is saved on the hard disk so that it can be loaded into RAM when the user runs it.

Why: A near-miss about secondary storage, which the mark scheme says not to accept; the stored program concept is about instructions being held in main memory.

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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