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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 marksWireless Connections Swap Remove

An office has one wireless access point that employees connect their laptops to.

Describe how connecting more devices to the wireless access point can affect the speed and latency of the network.

[2 marks]
Mark scheme

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

  • The bandwidth/capacity of the access point is shared between all the connected devices (1) so each device gets less bandwidth as more devices connect, which reduces the speed of data transfer (1)
  • The devices have to take turns to transmit (contention) (1) so each device waits longer before it can send data, which increases latency (1)
  • The access point can only support a maximum number of connections (1) so once this limit is reached, further devices cannot connect to the network (1)

Allow 'contention' as an alternative to devices having to take turns to transmit.

Allow 'the network becomes slower' as the second mark only where it is linked to shared bandwidth, to devices taking turns to transmit or to the maximum number of connections.

Do not accept a response that only states the network becomes slower, or that there are more devices/more traffic, without saying how this affects performance.

Do not accept responses about range or interference unless they are linked to the number of connected devices.

Example answers and how they were marked
Full marks2/2

All of the connected devices share the bandwidth of the access point, so as more devices are added each device gets less bandwidth and data is transferred more slowly.

Why: Shared bandwidth point (1) developed into the effect on the speed of data transfer (1).

Some marks1/2

The bandwidth of the access point has to be shared between all the devices that are connected to it.

Why: Correct point that bandwidth is shared (1), but there is no development saying how this affects the speed or latency, so only one mark.

No marks0/2

Each device gets its own bandwidth from the access point, so adding more devices does not change the speed.

Why: Misconception that bandwidth is not shared, so no creditworthy point is made.

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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