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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.

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4 questions · 7 marks

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1Short recall1 markCharacter Sets Swap Remove

A computer can store a maximum of 80 bits for a text message. Each character is stored using 7-bit ASCII.

State the maximum number of whole characters that can be stored in the message.

[1 mark]
Mark scheme

Award one mark for:

  • 11 (characters) (1)

Allow 11 remainder 3.

Allow 80 ÷ 7 = 11.428... rounded down to 11.

Do not accept 11.4 or 12 (rounding up or giving a decimal answer).

Do not award an unevaluated calculation such as 80 ÷ 7 with no answer.

Example answers and how they were marked
Full marks1/1

11

Why: Correct: 80 ÷ 7 = 11 remainder 3, so 11 whole characters can be stored (1).

No marks0/1

11.4

Why: Near miss: gives a decimal result rather than the number of whole characters; the mark scheme does not accept 11.4.

No marks0/1

12

Why: Rounds up to 12, but 12 characters would need 84 bits, more than the 80 available; the mark scheme does not accept 12.

2Short recall2 marksCompression Swap Remove

Images and sound can be stored using lossy compression.

Define the term lossy compression.

[2 marks]
Mark scheme

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

  • Reduces the size of a file (1)
  • Permanently removes/loses some data (1)
  • The original file cannot be recreated/restored exactly (1)

Allow 'some data is deleted/discarded and cannot be recovered' for the second mark.

Do not award the first mark where the response also states that no data is lost.

Do not accept 'removes repeated data' (this describes lossless compression).

Example answers and how they were marked
Full marks2/2

Lossy compression reduces the size of a file by permanently removing some data, so the original cannot be restored exactly.

Why: Reduces the size of a file (1); permanently removes some data (1); maximum two marks awarded.

Some marks1/2

It makes a file smaller.

Why: Reduces the size of a file (1); no reference to data being permanently lost.

No marks0/2

It makes a file smaller without losing any of the data.

Why: States that no data is lost, which describes lossless compression; the first mark is not awarded.

3Describe2 marksUser Management Swap Remove

An operating system manages the users of a computer.

Describe how an operating system checks that a user is allowed to log in.

[2 marks]
Mark scheme

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

  • The user enters a username/user ID and password/PIN (1) which is compared with the account details the operating system has stored (1)
  • The operating system keeps a file/list/database of users and their passwords (1) to check the login details the user enters against (1)
  • The operating system compares the entered details with the details stored for that user (1) and if they do not match, access is refused/denied (1)
  • The entered details are checked against the access rights stored for that user (1) so access is only allowed when the details are correct (1)

Do not award for 'it asks for a password' on its own, without saying what the password is checked against.

A stored list/file of users and passwords with no check of the login details earns one mark only.

Do not accept responses about file management, such as finding or opening the user's files.

Example answers and how they were marked
Full marks2/2

The user types in a username and password. The operating system compares these with the details it has stored for that account, and if they match the user is allowed to log in.

Why: Username and password entered (1) which is compared with the account details the operating system has stored (1).

Some marks1/2

The operating system has a list of all the users and their passwords.

Why: The stored list of users and passwords (1), but no check of the login details against it, so the development mark is not earned (0); the mark scheme states a list alone earns one mark only.

No marks0/2

The operating system finds the user's files on the hard drive and opens the last one they saved.

Why: Describes file management, not checking a user's login details; the mark scheme says not to accept responses about file management, so there is no creditworthy point.

4Convert2 marksDenary to Binary Conversion Swap Remove

Computer systems manipulate bit patterns.

Convert the denary number 140 to 8-bit binary.

[2 marks]
Mark scheme

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

  • 1000 (1)
  • 1100 (1)

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

Example answers and how they were marked
Full marks2/2

1000 1100

Why: 140 = 128 + 8 + 4: both nibbles are correct (2).

Some marks1/2

1000 1101

Why: Converts 141 instead (a slip in adding up the place values). The first nibble is correct (1); the second is not.

No marks0/2

0011 0001

Why: The bits are written in reverse, smallest place value first. Neither nibble is correct.

Questions by topic

5.3 Cybersecurity

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