Edexcel GCSE Computer Science (1CP2) exam questions

Build a practice paper from 514 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.

Practice paper

7 questions · 14 marks

Pick again

1Short recall2 marksWireless Connections Swap Remove

Latency affects the performance of a network.

Define the term latency.

[2 marks]

Mark scheme

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

A delay/time/lag (1)
Between a signal/request being sent and a response/data being received (1)

Allow 'the time taken for data to travel from source to destination' for both marks.

Do not accept 'the speed at which data travels' / 'bandwidth' / 'the amount of data sent per second'.

Example answers and how they were marked

Full marks2/2

The delay between a signal being sent and a response being received.

Why: Gives the delay (1) and the time between sending and receiving (1).

Some marks1/2

The time taken for data to travel.

Why: Gives the idea of time taken (1) but does not say between sending and receiving (1).

No marks0/2

The speed at which data is sent over the network.

Why: Describes speed, not latency; no creditworthy point.

2Short recall2 marksWired Connections Swap Remove

A school connects its desktop computers to the network using cables.

Give two reasons why the wired connections give better network performance than the wireless connections.

[2 marks]

Mark scheme

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

Faster transmission speed (1)
Higher bandwidth (1)
Lower latency (1)
Not affected by interference (from other devices/walls) (1)
No blind spots/not affected by distance from the wireless access point (1)

Do not accept benefits of wireless connections, e.g. users can move around the building with their devices

Do not accept 'easier to set up' or 'does not need a password' as these are not about network performance

Example answers and how they were marked

Full marks2/2

The wired connection is not affected by interference from other devices, and it has a lower latency than Wi-Fi.

Why: Interference point (1) and lower latency point (1).

Some marks1/2

It has a faster transmission speed and the users can move around the building with their computers.

Why: Faster transmission speed (1); moving around is a benefit of wireless, so is not credited.

No marks0/2

It is easier to set up the network and the users do not need a password.

Why: Neither point is about network performance; the mark scheme does not accept 'easier to set up' or password points, so no marks.

3Describe2 marksWired Connections Swap Remove

A school connects its desktop computers to the network using Ethernet cables.

Describe one way that using a wired connection can give a faster transfer of data than a wireless connection.

[2 marks]

Mark scheme

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

(Ethernet) cables are not affected by interference from other devices (1) so data is transferred at a consistent/steady speed (1)
Each device has its own cable to the switch (1) so the full bandwidth is available to that device and speeds do not drop as more users join (1)
Fibre optic cable has a higher bandwidth than a wireless link (1) so more data can be sent along the cable each second (1)
The cable gives a direct/physical path to the switch (1) so data is less likely to be lost and resent, which would slow the transfer (1)

Do not accept responses about security, reliability or users being unable to move around, as these are not about speed.

Do not accept answers that only say a wired/cable connection is faster, or that fibre is faster, without saying why.

Example answers and how they were marked

Full marks2/2

The cable is not affected by interference from other devices such as other networks or microwaves (1) so the data is sent at a steady speed instead of slowing down (1).

Why: Point that the cable is not affected by interference (1) linked to a consistent data transfer speed (1).

Some marks1/2

Ethernet cables are not affected by interference.

Why: Gives the first point of a linked pair (1) but does not develop it to say how this makes the transfer faster.

No marks0/2

A wired connection is faster because the data travels down a cable and not through the air.

Why: Repeats the question (wired is faster) with no reason, which the mark scheme's final line says is not accepted.

4Describe2 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 (1) so a switch is needed in each field to pass the readings on to the farmhouse (1).

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.

5Explain2 marksPacket Switching Swap Remove

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

Explain why each packet has a packet number in its header.

[2 marks]

Mark scheme

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

The receiver can put the packets back into the correct order (1) because packets may arrive out of order/take different routes (1)
The receiver can see if a packet is missing (1) because the sequence of numbers shows a gap (1)
The receiver knows when the whole file has arrived (1) because the total number of packets/last packet number is known (1)

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

Allow 'so the packets can be put back in the correct order/reassembled' for the first mark, but the second mark needs the reason, i.e. packets may arrive out of order/take different routes.

Do not accept 'so the packets can be identified' without stating what the number is used for, e.g. reordering or spotting a missing packet.

Do not accept 'so the router knows where to send it' - the router uses the destination IP address, not the packet number.

Example answers and how they were marked

Full marks2/2

The receiver can put the packets back in the correct order because they may arrive out of order.

Why: Linked point (1) and reason (1): the packet number allows reordering because packets can arrive out of order.

Some marks1/2

It shows the receiver the order of the packets.

Why: The point is given (1) but there is no linked reason, such as packets arriving out of order.

No marks0/2

So the router knows which route to use.

Why: Routers use the destination IP address, not the packet number, so this earns nothing; it is named in the mark scheme as a 'Do not accept'.

6Explain2 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.

7Explain2 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.

Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a paper

Practice paper

Questions by topic

2.1 Binary

2.2 Data representation

2.3 Data storage and compression

3.1 Hardware

3.2 Software

3.3 Programming languages

4.1 Networks

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