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Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 659 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 · 8 marks

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1Describe2 marksWireless Connections Swap Remove

A family uses a wireless network at home.

Describe how interference can affect the performance of a wireless network.

[2 marks]
Mark scheme

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

  • Other electrical/radio devices nearby (1) interfere with the wireless signal so data is corrupted (1)
  • Interference corrupts data (1) so the data has to be resent, which increases latency/slows the transfer (1)
  • Interference reduces the strength of the signal received (1) which lowers the data transfer rate the connection can support (1)
  • Interference makes the connection drop (1) so data transfer stops/devices have to reconnect (1)

Do not accept responses that only name a device (microwave, phone) without saying how it affects the network.

Do not accept responses that only state the network becomes slower without saying what causes the interference or how it affects the data.

Do not accept responses about wired connections or cables.

Example answers and how they were marked
Full marks2/2

Other electrical devices nearby can interfere with the wireless signal and corrupt data, so the data has to be resent and transfers are slower.

Why: Linked point: other electrical devices interfere and corrupt data (1), developed by the data being resent, which slows the transfer (1).

Some marks1/2

Other electrical devices nearby can interfere with the wireless signal.

Why: Cause given: other electrical devices interfere with the signal (1), but no development of how this affects the data or performance.

No marks0/2

Interference happens when the wireless cable is damaged by other cables.

Why: Misconception about cables; the mark scheme does not accept responses about wired connections or cables.

2Describe2 marksWired Connections Swap Remove

A hospital connects the computers on a ward using wired connections.

Describe how using wired connections can reduce latency on this network.

[2 marks]
Mark scheme

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

  • Data travels along the cable directly to the switch on a single continuous path (1) so the time between sending and receiving the data is short (1)
  • A cable is not affected by interference from other devices/wireless traffic nearby (1) so packets are not lost and resent, which would add to the delay (1)
  • The switch sends the data only to the port of the correct device, not to every device (1) so the data spends less time travelling and the delay is lower (1)
  • Fewer devices share a cable than share a wireless channel (1) so packets do not queue/wait before they are sent (1)

The first mark is for the way the wired connection carries the data; the second mark is for how this reduces the delay between sending and receiving.

Do not accept responses about bandwidth or the amount of data a cable can carry, as latency is the delay between sending and receiving.

Do not accept responses that confuse latency with speed/bandwidth, e.g. 'a wired connection is faster so there is less latency', unless they describe how the delay is reduced.

Do not accept answers that only say a wired connection is faster, with no link to the delay.

Example answers and how they were marked
Full marks2/2

The cable is not affected by interference from other devices so packets do not need to be resent and the delay stays low.

Why: First mark for the cable being free of interference (1); linked development that no packets are resent and so the delay is lower (1).

Some marks1/2

There is no interference from other devices on a cable.

Why: Gives the first point of a linked pair (1) but does not say how this reduces the delay between sending and receiving.

No marks0/2

Wired connections have a higher bandwidth so there is less latency.

Why: Confuses bandwidth with latency, which the 'Do not accept' lines rule out (0).

3Explain2 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 so each packet can be sent separately across the network.

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.

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 so they reach the right destination.

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

4Explain2 marksWired Connections Swap Remove

Latency is the delay between data being sent and received. A player of online games uses a wired Ethernet connection instead of a wireless connection.

Explain one reason why the wired connection can have a lower latency.

[2 marks]
Mark scheme

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

  • The cable provides a direct physical path to the switch/router (1) so data does not have to travel through the air where it can be delayed by obstacles such as walls (1)
  • The cable is not shared with other wireless devices (1) so data does not have to wait for a free channel before it is sent (1)
  • The data travels straight along the cable to the switch (1) so the time taken for it to reach its destination is short (1)

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

Do not accept 'the wired connection is faster' on its own without saying why the delay between sending and receiving is shorter.

Do not accept a definition of latency without a reason.

Example answers and how they were marked
Full marks2/2

The cable gives the computer a direct physical path to the switch, so the data does not have to travel through the air where it could be delayed by obstacles.

Why: Gives the point of a direct physical path (1) and links it to data not being delayed by obstacles in the air (1).

Some marks1/2

The wired connection gives a direct path, so it is quicker.

Why: Gives the point about the direct path (1) but 'quicker' only restates lower latency and does not explain why the delay is shorter.

No marks0/2

Wired connections have lower latency because the internet speed is faster.

Why: Confuses speed with latency; no reason is given for a shorter delay, and 'faster' on its own is not accepted.

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5.3 Cybersecurity

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