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.

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8 questions · 13 marks

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1Multiple choice1 markPacket Switching Swap Remove

Data is broken into packets and sent across the internet.

Identify the device that forwards a packet towards its destination.

[1 mark]

AHub
BRouter
CServer
DSwitch

Mark scheme

B Router (1)
The only correct answer is B. The correct answer is Router.
A is not correct because a hub sends the data it receives to every device on the network
C is not correct because a server provides services, such as web pages, to client computers
D is not correct because a switch forwards data between the devices on one network

Example answers and how they were marked

Full marks1/1

B Router

Why: Selected the correct device: a router reads the destination IP address in each packet and forwards it towards its destination (1).

No marks0/1

D Switch

Why: A near miss: a switch forwards data between devices on one network, but it is a router that forwards packets between networks towards their destination, so no mark.

No marks0/1

A Hub

Why: Misconception from the examiners' reports: confusing LAN hardware with internet routing. A hub sends data to every device on the network and does not read IP addresses to forward packets, so no mark.

2Short recall1 markAddressing Swap Remove

An IPv4 address is made up of four 8-bit numbers separated by dots.

State the range of values that each number in an IPv4 address can have.

[1 mark]

Mark scheme

Award one mark for:

0 to 255 (1)

Allow 0–255 / 0-255 / between 0 and 255 / 0 and 255.

Do not accept 1 to 255 (0 is a valid value).

Do not accept any range that includes 256, e.g. 0 to 256.

Example answers and how they were marked

Full marks1/1

0 to 255

Why: Gives the correct range (1).

No marks0/1

1 to 255

Why: Near miss: excludes 0, which is a valid value; the Do not accept line applies.

No marks0/1

0 to 256

Why: Includes 256, which is not valid; the Do not accept line applies.

3Short recall1 markWired Connections Swap Remove

Wired connections have characteristics that affect network performance.

State what is meant by the range of a wired network connection.

[1 mark]

Mark scheme

Award one mark for:

The maximum distance data/a signal can be transmitted before it becomes too weak to be received (1)

Allow 'how far a signal can travel'.

Do not accept the number of devices that can be connected to the network.

Do not accept the speed at which data is transmitted.

Do not accept bandwidth/the maximum capacity of a channel.

Do not accept latency/the delay between a signal being sent and received.

Example answers and how they were marked

Full marks1/1

The maximum distance a signal can be transmitted before it becomes too weak to be received.

Why: Gives the maximum distance a signal can be transmitted before it becomes too weak, which is the creditworthy point (1).

No marks0/1

The maximum capacity of the connection.

Why: This describes bandwidth, which the mark scheme says not to accept for range, so no mark.

No marks0/1

The delay between a signal being sent and received.

Why: This describes latency/delay, which the mark scheme says not to accept for range, so no mark.

4Short 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.

5Describe2 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 (1) so packets do not need to be resent and the delay stays low (1).

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).

6Describe2 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.

7Explain2 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'.

8Explain2 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

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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

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