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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 631 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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4 questions · 7 marks

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1Multiple choice1 markPacket Switching Swap Remove

Identify what a router does with a data packet it receives.

[1 mark]
  • AGives the packet a number
  • BSends it on to the next router
  • CPuts the packets into order
  • DRebuilds the original file
Mark scheme
  • B Sends it on to the next router (1)
  • The only correct answer is B. The correct answer is sends it on to the next router.
  • A is not correct because a packet is given its number by the sending computer before it is sent
  • C is not correct because packets are put back into order by the receiving computer
  • D is not correct because the original file is rebuilt by the receiving computer once all the packets arrive
Example answers and how they were marked
Full marks1/1

B Sends it on to the next router

Why: Selected the action a router performs on a packet it receives (1).

No marks0/1

D Rebuilds the original file

Why: A near miss: rebuilding the file is a packet switching action, but it is done by the receiving computer, not by a router.

No marks0/1

A Gives the packet a number

Why: Misconception: packets are numbered by the sending computer, so a router does not add a packet number.

2Short recall2 marksWireless Connections Swap Remove

Wireless connections use radio waves.

Give two reasons why a wireless connection can have a lower speed than a wired connection.

[2 marks]
Mark scheme

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

  • Interference from other electrical/electronic devices (1)
  • Walls/obstacles block or weaken the signal (1)
  • The signal gets weaker the further a device is from the access point (1)
  • Other devices/networks use the same wireless channel/frequency (1)
  • A wireless channel has less bandwidth than a wired connection (1)

Do not accept 'higher latency', because latency is a delay and does not reduce the speed at which data is transferred.

Do not accept 'wireless is slower' / 'wired is faster' without a reason.

Do not accept 'radio waves are slower than signals in a cable' as they travel at the same speed.

Example answers and how they were marked
Full marks2/2

Other electrical devices can cause interference, and walls can block the signal.

Why: Gives interference (1) and walls blocking the signal (1).

Some marks1/2

Walls can block the wireless signal.

Why: Gives one valid reason, walls blocking the signal (1), but no second reason.

No marks0/2

Wireless is slower because it has a higher latency, so the data takes longer to arrive.

Why: Confuses latency (a delay) with speed; 'higher latency' is not accepted and no other creditworthy reason is given.

3Explain2 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.

4Explain2 marksProtocols & Layers Swap Remove

The TCP/IP model has four layers.

Explain one function of the transport layer when a file is sent over a network.

[2 marks]
Mark scheme

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

  • Splits the data/file into packets (1) so each packet can be sent separately across the network (1)
  • Adds a packet/sequence number to each packet (1) so the packets can be put back into the correct order at the destination (1)
  • Detects lost/missing packets (1) so they can be requested/resent (1)
  • Creates a connection between the two computers/hosts (1) before the file is sent (1)

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

Allow 'segments' for 'packets' (TCP divides the data into segments, which become packets at the internet layer).

Do not accept 'sends the data/file' on its own without saying what the transport layer does to the data.

Do not accept naming TCP or a port number on its own without expansion.

Do not accept routing/addressing packets using IP addresses, which is the internet layer.

Example answers and how they were marked
Full marks2/2

The transport layer splits the data into packets (1) so each packet can be sent separately across the network (1).

Why: Linked point (1) and reason (1): splitting into packets lets each one be sent separately.

Some marks1/2

It splits the data into packets (1).

Why: Point (1) identified, but no linked reason given, so only the first mark is awarded.

No marks0/2

It routes the packets using IP addresses (0) so they reach the right destination.

Why: Routing using IP addresses is the internet layer, not the transport layer, so no credit is given.

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