Skip to content
Try on iPad

Boolean algebra: OCR A‑Level Computer Science questions

Every OCR A-Level Computer Science exam question on 1.4.3 Boolean algebra, 2021–2025, with its mark scheme and examiner’s report.

Find questions593
Calculations

593 questions

  1. Q5(a)

    June 2025 · Paper 1

    4 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2025 Paper 1, question 5(a): Complete the truth table for this half adder circuit. A B S C (Out) 0 0 0 1 1 0 1 1 [4]

  2. Q5(b)

    June 2025 · Paper 1

    2 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2025 Paper 1, question 5(b): Describe the difference between a half adder circuit and a full adder circuit. [2]

  3. Q5(c)

    June 2025 · Paper 1

    4 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2025 Paper 1, question 5(c): The diagram below shows a partially completed logic circuit for a full adder. The full adder circuit contains three inputs: • A – represents the first input • B

  4. Q5(d)

    June 2025 · Paper 1

    4 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2025 Paper 1, question 5(d): This Karnaugh map represents a different logic circuit. AB 00 01 11 10 00 0 1 1 1 01 0 1 1 0 CD 11 0 0 0 0 10 0 0 1 1 Use this Karnaugh map to find the simplifi

  5. Q8(a)

    June 2025 · AS Paper 1

    4 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2025 AS Paper 1, question 8(a): Complete the Karnaugh map for this expression and state the simplified expression. You should draw groups around the cells you are using to simply this expressi

  6. Q8(b)(i)

    June 2025 · AS Paper 1

    1 mark1.4.3 Boolean algebra
    The whole paper ↗
    June 2025 AS Paper 1, question 8(b)(i): State the name of this logic gate. [1]

  7. Q8(b)(ii)

    June 2025 · AS Paper 1

    1 mark1.4.3 Boolean algebra
    The whole paper ↗
    June 2025 AS Paper 1, question 8(b)(ii): Complete the truth table for this logic gate. A B C 0 0 0 1 1 0 1 1 [1]

  8. Q5(a)

    June 2024 · Paper 1

    4 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2024 Paper 1, question 5(a): The inputs to the alarm are as follows. Input System A Door sensor B Motion sensor C Alarm has been set D Test mode enabled Draw a logic circuit to show the log

  9. Q5(b)(i)

    June 2024 · Paper 1

    1 mark1.4.3 Boolean algebra
    The whole paper ↗
    June 2024 Paper 1, question 5(b)(i): Simplify the Boolean expression ¬A v ¬B using De Morgan’s First Law. [1]

  10. Q5(b)(ii)

    June 2024 · Paper 1

    1 mark1.4.3 Boolean algebra
    The whole paper ↗
    June 2024 Paper 1, question 5(b)(ii): Simplify the Boolean expression ¬(¬B) using double negation. [1]

  11. Q5(b)(iii)

    June 2024 · Paper 1

    2 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2024 Paper 1, question 5(b)(iii): Simplify the Boolean expression (A v B) ˄ (A v C) using distribution. [2]

  12. Q7(a)(i)

    June 2024 · AS Paper 1

    2 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2024 AS Paper 1, question 7(a)(i): Complete the truth table for this logic gate diagram. A B Q 0 0 0 1 1 0 1 1 [2]

  13. Q7(a)(ii)

    June 2024 · AS Paper 1

    1 mark1.4.3 Boolean algebra
    The whole paper ↗
    June 2024 AS Paper 1, question 7(a)(ii): What single gate is this logic gate diagram equivalent to? [1]

  14. Q7(b)

    June 2024 · AS Paper 1

    3 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2024 AS Paper 1, question 7(b): Draw the logic gate diagram for this expression: Q = (A ˅ ¬B) ˄ C [3]

  15. Q6(a)(i)

    June 2023 · Paper 1

    2 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2023 Paper 1, question 6(a)(i): Give the Boolean expression that represents the logic circuit shown in Fig. 6. Do not attempt to simplify the expression. [2]

  16. Q6(a)(ii)

    June 2023 · Paper 1

    3 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2023 Paper 1, question 6(a)(ii): Complete the truth table for the logic circuit shown in Fig. 6. A B C P 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 [3] The following Karnaugh map represent

  17. Q6(b)

    June 2023 · Paper 1

    4 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2023 Paper 1, question 6(b): Use this Karnaugh map to find the simplified expression for this circuit. You should highlight the map as appropriate and write the expression here. [4]

  18. Q5(a)

    June 2022 · AS Paper 1

    4 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2022 AS Paper 1, question 5(a): Complete the Karnaugh Map below to simplify this expression. Show your working. AB 00 01 11 10 00 01 CD 11 10 Simplified expression: [4]

  19. Q5(b)

    June 2022 · AS Paper 1

    3 marks1.4.3 Boolean algebra
    The whole paper ↗
    June 2022 AS Paper 1, question 5(b): Draw a Logic diagram for the following expression: Q = J(A / B) 0 (C /J D) A B Q C D [3]

  20. Q5(a)

    November 2021 · Paper 1

    3 marks1.4.3 Boolean algebra
    The whole paper ↗
    November 2021 Paper 1, question 5(a): Complete the Boolean expression below: Q ≡ [3]
All 24 questions on Boolean algebra, as a list
  1. June 2025, Paper 1, Q5(a) (4 marks): Complete the truth table for this half adder circuit. A B S C (Out) 0 0 0 1 1 0 1 1 [4]
  2. June 2025, Paper 1, Q5(b) (2 marks): Describe the difference between a half adder circuit and a full adder circuit. [2]
  3. June 2025, Paper 1, Q5(c) (4 marks): The diagram below shows a partially completed logic circuit for a full adder. The full adder circuit contains three inputs: • A – represents the first input • B
  4. June 2025, Paper 1, Q5(d) (4 marks): This Karnaugh map represents a different logic circuit. AB 00 01 11 10 00 0 1 1 1 01 0 1 1 0 CD 11 0 0 0 0 10 0 0 1 1 Use this Karnaugh map to find the simplifi
  5. June 2025, AS Paper 1, Q8(a) (4 marks): Complete the Karnaugh map for this expression and state the simplified expression. You should draw groups around the cells you are using to simply this expressi
  6. June 2025, AS Paper 1, Q8(b)(i) (1 mark): State the name of this logic gate. [1]
  7. June 2025, AS Paper 1, Q8(b)(ii) (1 mark): Complete the truth table for this logic gate. A B C 0 0 0 1 1 0 1 1 [1]
  8. June 2024, Paper 1, Q5(a) (4 marks): The inputs to the alarm are as follows. Input System A Door sensor B Motion sensor C Alarm has been set D Test mode enabled Draw a logic circuit to show the log
  9. June 2024, Paper 1, Q5(b)(i) (1 mark): Simplify the Boolean expression ¬A v ¬B using De Morgan’s First Law. [1]
  10. June 2024, Paper 1, Q5(b)(ii) (1 mark): Simplify the Boolean expression ¬(¬B) using double negation. [1]
  11. June 2024, Paper 1, Q5(b)(iii) (2 marks): Simplify the Boolean expression (A v B) ˄ (A v C) using distribution. [2]
  12. June 2024, AS Paper 1, Q7(a)(i) (2 marks): Complete the truth table for this logic gate diagram. A B Q 0 0 0 1 1 0 1 1 [2]
  13. June 2024, AS Paper 1, Q7(a)(ii) (1 mark): What single gate is this logic gate diagram equivalent to? [1]
  14. June 2024, AS Paper 1, Q7(b) (3 marks): Draw the logic gate diagram for this expression: Q = (A ˅ ¬B) ˄ C [3]
  15. June 2023, Paper 1, Q6(a)(i) (2 marks): Give the Boolean expression that represents the logic circuit shown in Fig. 6. Do not attempt to simplify the expression. [2]
  16. June 2023, Paper 1, Q6(a)(ii) (3 marks): Complete the truth table for the logic circuit shown in Fig. 6. A B C P 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 [3] The following Karnaugh map represent
  17. June 2023, Paper 1, Q6(b) (4 marks): Use this Karnaugh map to find the simplified expression for this circuit. You should highlight the map as appropriate and write the expression here. [4]
  18. June 2022, AS Paper 1, Q5(a) (4 marks): Complete the Karnaugh Map below to simplify this expression. Show your working. AB 00 01 11 10 00 01 CD 11 10 Simplified expression: [4]
  19. June 2022, AS Paper 1, Q5(b) (3 marks): Draw a Logic diagram for the following expression: Q = J(A / B) 0 (C /J D) A B Q C D [3]
  20. November 2021, Paper 1, Q5(a) (3 marks): Complete the Boolean expression below: Q ≡ [3]
  21. November 2021, Paper 1, Q5(b)(i) (2 marks): Simplify this Boolean expression so that it does not include any negation. You must explain which Boolean algebra rule(s) you are using at each step. [2]
  22. November 2021, Paper 1, Q5(c)(i) (2 marks): Give the Boolean expressions for the outputs S and C. S ≡ C ≡ [2]
  23. November 2021, Paper 1, Q5(c)(ii) (2 marks): Complete the truth table for this logic circuit. A B S C 0 0 0 1 1 0 1 1 [2]
  24. November 2021, Paper 1, Q5(c)(iii) (4 marks): Describe how this logic circuit can be adapted to add together two 4-bit binary numbers. [4]

Questions, mark schemes and examiner’s reports are © OCR, from their published past papers. Plumi isn’t affiliated with any exam board. Want whole papers? Full past papers.

Rather write your answers by hand on iPad? Plumi marks them against the same mark schemes.