Paper: Boolean Logic Practice Test (Topic 3.4.2)
Time allowed: 1 hour
Maximum marks: 50
Instructions:
Q1. Which logic gate produces a 1 output only if both inputs are 1?
A. OR
B. NOT
C. AND
D. XOR
(1 mark)
Q2. What is the output of NOT(1)?
A. 0
B. 1
C. 10
D. Cannot be determined
(1 mark)
Q3. Which of the following truth tables matches the XOR gate?
(1 mark)
| A | B | Output |
|---|---|---|
| 0 | 0 | ? |
| 0 | 1 | ? |
| 1 | 0 | ? |
| 1 | 1 | ? |
Options:
A. 0 0 1 1
B. 0 1 1 0
C. 1 0 0 1
D. 1 1 0 0
Q4. Which Boolean expression matches this circuit?
Inputs A and B go into an AND gate. Input C goes into a NOT gate. The outputs of both gates are fed into an OR gate.
(1 mark)
A. (A AND B) OR (NOT C)
B. (A OR B) AND (NOT C)
C. NOT(A AND B) OR C
D. (A OR B) OR (NOT C)
Q5. Which gate is known as the “inverter”?
(1 mark)
Q6. Complete the truth table for the Boolean expression:(A OR B) AND NOT(C)
(3 marks)
| A | B | C | Output |
|---|---|---|---|
| 0 | 0 | 0 | ? |
| 0 | 0 | 1 | ? |
| 0 | 1 | 0 | ? |
| 0 | 1 | 1 | ? |
| 1 | 0 | 0 | ? |
| 1 | 0 | 1 | ? |
| 1 | 1 | 0 | ? |
| 1 | 1 | 1 | ? |
Q7. Draw a logic circuit diagram for the Boolean expression:(A XOR B) AND C
(3 marks)
Q8. State two uses of logic gates in real-world digital systems.
(2 marks)
Q9. Simplify the Boolean expression:(A AND 1)
(1 mark)
Q10. A student claims the expression (A OR 0) simplifies to 0. Is the student correct? Justify your answer.
(2 marks)
Q11. Simplify the Boolean expression:NOT(NOT A)
(1 mark)
Q12. Draw the truth table for:(A AND B)
(3 marks)
Q13. Simplify the Boolean expression:(A AND B) OR (A AND NOT B)
Show working.
(3 marks)
Q14. A circuit has three inputs: A, B, and C. The circuit outputs 1 if:
1, otherwise output 0.(a) Write a Boolean expression for this circuit.
(b) Complete the truth table.
(6 marks)
Q15. A password system uses three checks:
The system allows access only if A and B are true, or C is true.
(a) Write a Boolean expression for this system.
(b) Draw the corresponding logic circuit.
(c) Complete the truth table.
(8 marks)
Q16. Simplify the Boolean expression using Boolean algebra rules:(A OR B) AND (A OR NOT B)
(4 marks)
Q17. Challenge:
Explain the difference between XOR and OR, and give one real-world example where XOR would be used instead of OR.
(4 marks)