Menu

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.

Build a paper

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

Practice paper

3 questions · 6 marks

Pick again
Print
1Describe2 marksWired Connections Swap Remove

A video production company stores large video files on a server. The server is connected to the office switch by an Ethernet cable with a bandwidth of 1 Gbps.

Describe how the bandwidth of this wired connection affects the performance of the network.

[2 marks]
Mark scheme

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

  • Bandwidth is the maximum amount/capacity of data that can be carried each second (1) so a higher bandwidth lets editors open the large video files from the server in less time (1)
  • The bandwidth of the cable is set by the type/standard of cable used (1) so it limits how much of a large file can be sent in a given time (1)
  • A higher bandwidth means the cable can be shared between more transfers at the same time (1) so several editors can open files from the server at once without their transfers slowing down (1)
  • If the bandwidth is too low for the size of the files (1) the transfers take a long time and the editors have to wait for their files to open (1)

Allow 'capacity' for 'maximum amount of data'.

A description that only defines bandwidth earns a maximum of one mark.

Do not accept responses about the time a signal takes to travel (latency) or the distance a signal can reach (range).

Do not accept answers that say bandwidth is how fast the signal/data travels along the cable, that a higher bandwidth gives a faster internet connection, or that bandwidth is the number of cables in the network.

Example answers and how they were marked
Full marks2/2

Bandwidth is the maximum amount of data that can be carried along the cable each second, so a higher bandwidth means the editors can open the large video files from the server in less time.

Why: Point defining bandwidth as the maximum data per second (1) linked to the effect on opening the large files (1).

Some marks1/2

It is the amount of data that can be carried along the cable each second.

Why: Gives the first part of a linked pair (1) but does not develop it to say how performance is affected, so it is capped at one mark.

No marks0/2

A higher bandwidth means the signal travels faster along the cable, so the data reaches the server sooner and the delay is shorter.

Why: Treats bandwidth as transmission speed/latency, which the mark scheme says is not accepted, so no mark is earned.

2Explain2 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'.

3Explain2 marksWireless Connections Swap Remove

An office wireless network is near a microwave oven and several other wireless networks.

Explain how interference can affect the speed of a wireless network.

[2 marks]
Mark scheme

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

  • The speed of data transfer is reduced/is slower (1) because interference corrupts the radio signal, so data/packets are lost and have to be resent/retransmitted (1)
  • The network speed is lower (1) because there is more noise on the wireless signal, so data is sent at a lower transmission rate (1)
  • The throughput of the wireless network is reduced (1) because time is used resending corrupted data/packets instead of sending new data (1)

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

Award 1 mark for a statement that the speed/transfer rate is reduced (e.g. slower, takes longer), even if no reason is given.

Do not accept 'interference damages/corrupts the radio signal' or 'the signal is weaker' on its own without a link to the speed.

Do not accept 'data is lost' on its own without saying how this reduces the speed.

Do not accept 'interference increases the bandwidth' or 'interference makes the signal stronger'.

Example answers and how they were marked
Full marks2/2

Interference corrupts the radio signal, so packets are lost and resent, which makes the data transfer slower.

Why: Linked point (1): data transfer is slower; reason (1): interference corrupts the signal so packets are lost and resent.

Some marks1/2

The speed of the wireless network will be lower.

Why: Point only (1): states the effect on speed. No linked reason why interference causes this.

No marks0/2

Interference increases the bandwidth, so the data travels faster.

Why: Misconception that interference increases bandwidth; the mark scheme says not to accept this.

Questions by topic

5.3 Cybersecurity

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.