Menu

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.

Build a paper

Topics (none ticked: all of them)
Question types (none ticked: all of them)

Practice paper

4 questions · 8 marks

Pick again
Print
1Describe2 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).

2Explain2 marksProtocols & Layers Swap Remove

Two computers exchange data over a network.

Explain why network protocols are needed for the two computers to communicate.

[2 marks]
Mark scheme

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

  • Devices (can) understand/interpret the data they receive (1) because they follow the same set of rules for communication (1)
  • Data is sent in an agreed format/structure (1) so the receiving device can interpret/understand it correctly (1)
  • Devices (can) connect/communicate successfully (1) because they agree how the data is transmitted, such as the type of signal used (1)
  • Errors (can) be detected/handled (1) because both devices follow the same rules for checking the data (1)

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

Do not accept 'so devices can talk/communicate with each other' or 'so they can understand each other' without saying they follow the same rules/agreed format.

Do not accept an answer that only states protocols are a set of rules, without saying what this allows (e.g. the data can be understood/interpreted).

Do not accept a faster connection/speed as a reason why protocols are needed.

Do not accept naming a protocol (e.g. TCP/IP, HTTP, Wi-Fi) without an explanation of why it is needed.

Do not accept a description of what a protocol does (e.g. 'TCP splits data into packets') without saying why this is needed.

Example answers and how they were marked
Full marks2/2

Devices can understand the data they receive because they follow the same set of rules for communication.

Why: Linked point (1) and reason (1): following the same rules is what lets the devices understand the data.

Some marks1/2

Data is sent in an agreed format.

Why: Point (1) identified, but no linked reason saying what the agreed format achieves.

No marks0/2

Protocols are needed so the connection is faster because more data can be sent at once.

Why: Speed is not a reason protocols are needed, so there is no creditworthy point or linked reason.

3Explain2 marksThe Internet Swap Remove

Each data packet has a header that contains the destination IP address.

Explain one reason why a data packet contains the destination IP address.

[2 marks]
Mark scheme

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

  • Routers can forward the packet towards its destination (1) because they read the destination IP address in the packet header (1)
  • The packet is delivered to the correct device (1) because the receiving device compares the destination IP address with its own IP address (1)
  • Each packet can take a different route (1) because routers use the destination IP address to choose the next router (1)
  • The packet can be passed on by each router in turn (1) because the destination IP address shows which network the packet is for (1)

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

Statements such as 'so it reaches the right destination' or 'so routers know where to send it' earn the first mark only; do not award the second mark unless the reason says that the address is read from the packet header and used to forward the packet.

Do not accept 'so it knows where it came from' as this describes the source address, not the destination address.

Do not accept 'so it gets there faster' without a linked reason.

Example answers and how they were marked
Full marks2/2

Routers know where to send it because they use the address in the packet header to choose the next network.

Why: Linked point (1) and reason (1): routers read the destination IP address in the header to forward the packet.

Some marks1/2

So that it reaches the right destination because every packet has an address.

Why: First mark (1) for reaching the right destination, but the reason is circular and does not say the address is read and used to forward the packet.

No marks0/2

So the packet knows where it came from.

Why: Describes the source address, not the destination address; do not accept.

4Explain2 marksWireless Connections Swap Remove

A student plays an online game using a laptop connected to the school Wi-Fi.

Explain one reason why an online game can respond more slowly over a wireless connection than over a wired connection.

[2 marks]
Mark scheme

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

  • Wireless signals can be blocked or absorbed by walls (1) so the data must be re-sent, which adds delay (1)
  • A device further from the access point has a weaker signal (1) so data must be re-sent/transmitted at a lower rate, adding delay (1)
  • Devices on a wireless network share a channel (1) so a device must wait its turn to transmit, which adds delay (1)
  • Interference from other devices affects the radio signal (1) so data must be re-sent, adding delay (1)

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

Allow 'waiting to send' or 'collisions' as the delay caused by devices sharing a channel.

Do not accept 'wireless is slower than wired' on its own, as this repeats the question.

Do not accept a reason that only affects download speed/bandwidth (e.g. 'files take longer to download') without a link to delay.

Example answers and how they were marked
Full marks2/2

Interference from other devices affects the radio signal, so the data has to be re-sent and this adds delay before the player's action appears.

Why: Linked point (1): interference affects the signal; reason (1): re-sending the data adds delay (latency).

Some marks1/2

Walls can block the wireless signal.

Why: Point only (1): walls block the signal. No linked reason saying that this means data must be re-sent, which adds delay.

No marks0/2

Wireless has less bandwidth than wired, so a game update takes longer to download.

Why: Confuses latency with bandwidth/download speed; the mark scheme says not to accept this without a link to delay.

Questions by topic

More ways to revise Edexcel GCSE Computer Science (1CP2)

Teachers: build a paper, print it with the mark schemes at the end, and sign your school up to set your classes activities on every topic.

Fetch Decode Explain isn't affiliated with or endorsed by Pearson Edexcel.