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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 693 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 · 6 marks

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1Describe2 marksWired Connections Swap Remove

A farm uses wired connections to link sensors in its fields to a computer in the farmhouse.

Describe how the range of a wired connection can affect the performance of this network.

[2 marks]
Mark scheme

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

  • (Twisted pair/copper) cable only carries data over a limited distance (about 100 metres) (1) so sensors further away need another switch/device to pass the data on to the farmhouse (1)
  • Fibre optic cable can carry data over much longer distances (1) so wired connections can reach sensors across the whole farm (1)
  • Data sent further than the cable's range is not received (1) so the computer in the farmhouse does not get readings from those sensors (1)
  • A wireless connection can reach sensors that are out of range of the cables (1) so a mix of the two can give readings across the whole site (1)

Allow responses about signal weakening/being lost over a long cable.

Do not accept responses about bandwidth or speed, as range is about distance, not the amount or rate of data.

Example answers and how they were marked
Full marks2/2

Twisted pair copper cable only carries data for about 100 metres so a switch is needed in each field to pass the readings on to the farmhouse.

Why: Point that copper cable has a limited distance (1) linked to needing another device to extend the network (1).

Some marks1/2

Fibre optic cable can carry data much further than copper cable.

Why: Gives the first point of a linked pair (1) but does not develop it to say what this allows the farm to do.

No marks0/2

A longer cable gives the network a bigger bandwidth so the sensors work faster.

Why: About bandwidth and speed rather than range, which the mark scheme says is not accepted.

2Explain2 marksPacket Switching Swap Remove

A router connects a home network to the internet.

Explain how a router uses the destination IP address in a packet header.

[2 marks]
Mark scheme

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

  • The router reads the destination IP address (1) so it knows which network/device the packet is for (1)
  • The router looks up the destination IP address in its routing table (1) to find the next router/route for the packet (1)
  • The router forwards the packet to the next router (1) that leads towards that IP address / is on the best route (1)

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

Do not accept MAC address - routers use the IP address to route packets between networks.

Do not accept 'it finds the exact device' without saying how the router uses the address, e.g. routing table/next router.

Example answers and how they were marked
Full marks2/2

The router looks up the destination IP address in its routing table to find the next router to send the packet to.

Why: Linked point (1) and reason (1): looks up the destination IP address in the routing table to find the next router.

Some marks1/2

It reads the destination IP address.

Why: Reads the destination IP address (1) but gives no linked reason about a routing table or next router.

No marks0/2

It reads the MAC address so it knows which computer sent the packet.

Why: Routers use the IP address to route packets, not the MAC address; no creditworthy point.

3Explain2 marksAddressing Swap Remove

Data is split into packets before it is sent over the internet.

Explain why each device that receives packets over the internet needs a unique IP address.

[2 marks]
Mark scheme

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

  • Data/packets are delivered to the correct/intended device (1) because the destination IP address identifies that device, so a duplicate address would mean packets could be delivered to the wrong device (1)
  • Replies are sent back to the device that requested the data (1) because the sender's IP address identifies that device, so a duplicate address would mean the reply could be sent to the wrong device (1)
  • The device can be identified separately from other devices (1) so packets are not delivered to a different device that has the same address (1)

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

Award one mark for a valid point and a second mark only for a linked reason explaining why a duplicate address would cause a problem.

Do not accept 'it is unique'/'it has its own address' as a point, as this repeats the question.

Do not accept 'so it can connect to the internet' or 'so it can be found' on its own without a link to data/packets being delivered to the correct device.

Allow 'data' for 'packets'.

Example answers and how they were marked
Full marks2/2

Packets are delivered to the correct device because the destination IP address identifies one device, so if two devices had the same address packets could be sent to the wrong one.

Why: Point that packets reach the correct device (1) and linked reason that a duplicate address would cause misdelivery (1).

Some marks1/2

Packets are sent to the correct device because it has its own IP address.

Why: Valid point that packets reach the correct device (1), but the reason only restates uniqueness and does not explain how a duplicate address would cause a problem, so no second mark.

No marks0/2

So that it can connect to the internet.

Why: No link to packets/data being delivered to the correct device; the mark scheme rejects a connection statement on its own.

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