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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 530 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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5 questions · 6 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.

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 recall1 markSecondary Memory Swap Remove

Data is stored on optical discs as pits and lands.

Name the component in an optical disc drive that reads this data.

[1 mark]
Mark scheme

Award one mark for:

  • Laser (1)

Allow laser beam

Do not accept read/write head

Do not accept pits

Do not accept lands

Do not accept reflective surface

Do not accept magnet/magnetic

Example answers and how they were marked
Full marks1/1

Laser

Why: Laser is the creditworthy answer (1).

No marks0/1

A read/write head

Why: Read/write head is not accepted by the mark scheme; it reads magnetic media, not optical discs, so no marks are awarded.

No marks0/1

Pits and lands

Why: Pits and lands are what the laser reads, not the component that reads the data, so the mark scheme does not accept them.

4Short recall1 markCompression Swap Remove

A company backs up its files to an external hard drive.

Give one reason why the company compresses the files before backing them up.

[1 mark]
Mark scheme

Award one mark for any of the following:

  • More files/data can be stored (in the same storage space) (1)
  • The files take up less storage space (1)
  • The backup is quicker/faster to complete (1)
  • Less data needs to be transferred to the backup device (1)

Do not accept 'makes the files more secure' or 'encrypts the files'.

Example answers and how they were marked
Full marks1/1

The compressed files take up less storage space, so more files can be backed up.

Why: The files take up less storage space (1).

No marks0/1

It reduces the amount of disk fragmentation.

Why: Near-miss: compression does not reduce disk fragmentation.

No marks0/1

It encrypts the files so they are safer if the drive is stolen.

Why: Misconception: compression does not encrypt files, and security is not accepted.

5Explain2 marksPacket Switching Swap Remove

A file is sent across the internet in packets.

Explain why packets from the same file may take different routes.

[2 marks]
Mark scheme

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

  • Each router chooses the best route at the time (1) so when a route becomes busy/congested or fails, later packets are forwarded along a different path (1)
  • Routers forward each packet separately (1) so the path a packet takes depends on the traffic conditions when that packet arrives (1)
  • A router may send a packet to a different next router (1) if its routing table shows a better/less congested route for that packet (1)
  • Traffic on the internet changes (1) so no single path is kept for the file and each packet can use whichever route is best when it is sent (1)

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

Allow reference to a routing table, or to how a router decides the route, as part of the linked reason.

Do not accept 'the packets have different IP addresses' because all packets from the same file have the same destination IP address, even though their routes can differ.

Do not accept 'the internet is busy' or 'there is a lot of traffic' on its own without linking this to the router choosing a different route.

Do not accept 'different routers send the packets' on its own without a reason why a different router/route is chosen.

Do not accept an answer that only says the packets take different routes without explaining why.

Example answers and how they were marked
Full marks2/2

Each router chooses the best route at the time, so if one route becomes busy or fails, later packets are sent a different way.

Why: Linked point (1) that each router chooses the best route at the time and reason (1) that a busy or failed route means later packets take a different path.

Some marks1/2

Routers send packets along the least congested route.

Why: States that a router chooses the least congested route (1) but gives no linked reason why this makes the packets from the file take different routes.

No marks0/2

Because each packet is given a different IP address so they go to different places.

Why: Misconception named in the mark scheme: all packets from the same file share the same destination IP address, even though their routes can differ.

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