Menu

Edexcel GCSE Computer Science (1CP2) Exam Questions

Build a practice paper from 604 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 · 7 marks

Pick again
Print
1Short recall3 marksFetch Decode Execute Cycle Swap Remove

The fetch-decode-execute cycle is used by the CPU.

State three things that happen during the fetch stage.

[3 marks]
Mark scheme

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

  • The address (of the next instruction) is sent from the CPU to main memory / placed on the address bus (1)
  • The (next) instruction is fetched/read from main memory (RAM) (1)
  • The instruction is brought/copied into the CPU / received into the MDR (1)
  • The program counter (PC) is incremented/updated to hold the address of the next instruction (1)

Allow 'the PC/MAR is placed on the address bus' for the address being sent to main memory.

Allow 'the MDR receives the instruction' for the instruction being brought into the CPU.

Do not award a second mark for the instruction being fetched from main memory and the instruction being brought into the CPU; these are the same point.

Do not award 'the instruction is transferred along the data bus' on its own; this is the same point as the instruction being fetched from main memory.

Do not accept answers about decoding the instruction, e.g. 'the instruction is fetched from RAM and decoded', as decoding happens in the decode stage.

Do not accept answers about the execute stage, e.g. 'the ALU carries out the calculation' or 'the result of a calculation is stored in a register', as these happen in the execute stage.

Example answers and how they were marked
Full marks3/3

The address of the next instruction is sent to main memory, the instruction is fetched from RAM, and the program counter is incremented.

Why: Address sent to main memory (1), instruction fetched from RAM (1) and program counter incremented (1).

Some marks1/3

The instruction is fetched from main memory and then decoded.

Why: Fetching the instruction from main memory (1); decoding happens in the decode stage, so it is not creditworthy in the fetch stage.

No marks0/3

The ALU carries out the calculation and the result is stored in a register.

Why: The ALU carrying out a calculation and storing a result happen in the execute stage, not the fetch stage, so no point is creditworthy.

2Explain2 marksThe Internet Swap Remove

A home network is connected to the internet by a router.

Explain one reason why a home network uses a router to connect its devices to the internet.

[2 marks]
Mark scheme

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

  • All the devices can share one internet connection (1) because the router forwards data packets between the home network and the internet (1)
  • Data can reach the correct device on the home network (1) because the router uses the destination IP address to forward each packet to that device (1)
  • Each device does not need its own separate connection to the internet (1) because the router forwards data packets for all the devices between the home network and the internet (1)

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

Do not accept 'it provides Wi-Fi' because Wi-Fi is not why a router is needed to connect to the internet.

Do not accept 'it connects the home network/devices to the internet' or 'a router connects networks' without saying what the router does with the data, as this restates the question.

Do not accept 'it connects the cables' without saying what it does with the data.

Example answers and how they were marked
Full marks2/2

It lets all the devices share the internet connection because it forwards their data packets between the home network and the internet.

Why: Linked point (1) and reason (1): the router forwards data packets between the home network and the internet.

Some marks1/2

All the devices can share one internet connection because it connects the home network to the internet.

Why: Point (1) for sharing one internet connection, but the reason only restates that it connects the network to the internet, which the scheme does not accept.

No marks0/2

It provides Wi-Fi for the devices.

Why: Wi-Fi is not why a router is needed to connect to the internet; do not accept.

3Calculate2 marksAdding Binary Numbers Swap Remove

Binary patterns can represent numbers.

Complete the table to show the result of the 8-bit binary addition.

[2 marks]
1286432168421
10010110
01011100
Mark scheme

Award one mark for each correct nibble in the correct order:

  • 1111 (1)
  • 0010 (1)

0 marks if the response is not 8-bit binary.

Example answers and how they were marked
Full marks2/2

1111 0010

Why: 150 + 92 = 242, carrying where a column adds to 2: both nibbles are correct (2).

Some marks1/2

1111 0011

Why: A slip in the last bit. The first nibble is correct (1); the second is not.

No marks0/2

1101 1110

Why: Writes 1 in every column with a 1 and never carries. Neither nibble is correct.

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.