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

4 questions · 6 marks

Pick again
Print
1Multiple choice1 markCharacter Sets Swap Remove

Characters are encoded using 7-bit ASCII.

Identify the number of different characters that can be represented using 7-bit ASCII.

[1 mark]
  • A64
  • B127
  • C128
  • D256
Mark scheme
  • C 128 (1)
  • The only correct answer is C. The correct answer is 128.
  • A is not correct because 6 bits give only 64 different combinations
  • B is not correct because 127 is the largest 7-bit value, not the number of characters that 7 bits can represent
  • D is not correct because 256 characters need 8 bits, as used by 8-bit extended ASCII
Example answers and how they were marked
Full marks1/1

C 128

Why: Selects the only correct option (1): 7 bits give 2 to the power of 7, which is 128 different characters.

No marks0/1

D 256

Why: Near miss scoring 0: 256 is the number of characters that 8 bits give in extended ASCII, not 7-bit ASCII.

No marks0/1

B 127

Why: Misconception scoring 0, the off-by-one error the examiners' report describes: 127 is the largest 7-bit value, but 7 bits give 128 different characters.

2Short recall2 marksStored Program Computers Swap Remove

The central processing unit (CPU) contains an arithmetic logic unit (ALU).

State two types of operation carried out by the ALU.

[2 marks]
Mark scheme

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

  • An arithmetic operation, e.g. addition/subtraction/multiplication/division (1)
  • A logical operation, e.g. comparing two values (is A > B?) / using AND, OR, NOT (1)

Do not accept decoding instructions, fetching instructions or controlling the timing of the CPU, as these are carried out by the control unit.

Example answers and how they were marked
Full marks2/2

It carries out arithmetic operations such as addition and subtraction, and logical operations such as comparing two values to see if one is greater than the other.

Why: Arithmetic operation (1) and logical operation (1).

Some marks1/2

It adds numbers together and works out the result.

Why: Arithmetic operation, addition (1). No logical operation.

No marks0/2

It decodes the instructions that have been fetched from main memory.

Why: Decoding and fetching are the control unit's role; the mark scheme's do-not-accept line covers this.

3Short recall1 markCompression Swap Remove

A company backs up its files to an external hard drive.

Give one reason why the company compresses the files before backing them up.

[1 mark]
Mark scheme

Award one mark for any of the following:

  • More files/data can be stored (in the same storage space) (1)
  • The files take up less storage space (1)
  • The backup is quicker/faster to complete (1)
  • Less data needs to be transferred to the backup device (1)

Do not accept 'makes the files more secure' or 'encrypts the files'.

Example answers and how they were marked
Full marks1/1

The compressed files take up less storage space, so more files can be backed up.

Why: The files take up less storage space (1).

No marks0/1

It reduces the amount of disk fragmentation.

Why: Near-miss: compression does not reduce disk fragmentation.

No marks0/1

It encrypts the files so they are safer if the drive is stolen.

Why: Misconception: compression does not encrypt files, and security is not accepted.

4Explain2 marksThe Internet Swap Remove

Routers on the internet choose a route for each packet.

Explain one benefit of a router being able to choose a different route for a packet.

[2 marks]
Mark scheme

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

  • Data can avoid a busy/congested link (1) because the router can choose another path (1)
  • Data can still arrive if a link fails (1) because the router sends it another way (1)
  • Data can take the shortest/fastest path (1) because the router compares the routes and chooses the one with the fewest hops/least traffic (1)

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

Allow other valid benefits with a linked reason, e.g. traffic can be shared across routes/load balanced (1) because the router can send some packets by another path (1)

Do not accept 'the route is always the same' as this is not a benefit of choosing a route.

Do not accept 'routers are fast' or 'packets are sent faster' on its own: the reason must say how the route is chosen, e.g. avoiding congestion or using a routing table.

Example answers and how they were marked
Full marks2/2

If one route is busy, the data can still get there (1) because the router can choose a different path (1).

Why: Linked point (1) and reason (1): a different path avoids the busy route.

Some marks1/2

It can choose the fastest route (1) because routers are quick (1).

Why: Point (1) for choosing the fastest route, but 'routers are quick' is a speed statement that does not say how the route is chosen, so it does not earn the second mark.

No marks0/2

It means more devices can connect to the internet.

Why: No link to choosing a route for a packet; does not answer the question.

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.