Logic Gate MCQ
Logic Gate MCQ, Objective Questions on Logic Gate, digital logic gate questions, MCQ on logic gate, digital logic design multiple-choice questions, Engineering MCQ, Multiple Choice Question based on Engineering, Digital Electronics MCQ, AND Gate MCQ, OR Gate MCQ, NAND Gate MCQ, Objective Questions on Logic Gate
Multiple Choice Questions
Q.1. What logic function is produced by adding inverters to the inputs of an OR gate?
- NOR
- NAND
- AND
- X-NOR
Answer: NAND
Q.2. What logic function is produced by adding an inverter to each input and output of an AND gate?
- NOR
- NAND
- X-OR
- OR
Answer: OR
Q.3. What logic function is produced by adding an inverter to each input and output of an OR gate?
- NAND
- NOR
- AND
- X-OR
Answer: AND
Q.4. Which of the following gates is known as a coincidence detector?
- AND gate
- NAND gate
- X-OR
- X-NOR gate
Answer: X-NOR gate
Q.5. Which of the following gates is known as anticoincidence detector?
- OR gate
- X-OR gate
- AND gate
- X-NOR gate
Answer: X-OR gate
Q.6. The output of a NOR gate is high
- only when all the inputs are low
- only when all the inputs are high
- only when at least one input is high
- only when at least one input is low
Answer: only when all the inputs are low
Q.7. The output of a NAND gate is low
- only when all the inputs are low
- only when all the inputs are high
- only when at least one input is high
- only when at least one input is low
Answer: only when all the inputs are high
Q.8. How many NOR gates are required to obtain AND operation?
- 2
- 3
- 4
- 1
Answer: 3
Q.9. What is the minimum number of NAND gates required to realize an X-OR gate?
- 3
- 4
- 5
- 6
Answer: 4
Q.10. What is the minimum number of NOR gates required to realize an X-OR gate?
- 3
- 4
- 5
- 6
Answer: 5
Q.11. An AND gate can be imagined as
- switches connected in series
- switches connected in parallel
- transistors connected in series
- transistors connected in parallel
Answer: switches connected in series
Q.12. An OR gate can be imagined as
- switches connected in series
- switches connected in parallel
- transistors connected in series
- transistors connected in parallel
Answer: switches connected in parallel
Q.13. An all or nothing gate is the other name of
- AND gate
- OR gate
- X-OR gate
- X-NOR gate
Answer: AND gate
Q.14. An any or all gate is the other name of
- AND gate
- OR gate
- X-OR gate
- X-NOR gate
Answer: OR gate
Q.15. A bubbled AND gate is equivalent to a
- OR gate
- NAND gate
- NOR gate
- X-OR gate
Answer: NOR gate
Q.16. A bubbled OR gate is equivalent to a
- AND gate
- NAND gate
- NOR gate
- X-OR gate
Answer: NAND gate
Q.17. A bubbled NAND gate is equivalent to
- OR gate
- NAND gate
- NOR gate
- X-OR gate
Answer: OR gate
Q.18. A bubbled NOR gate is equivalent to a
- AND gate
- NAND gate
- NOR gate
- X-OR gate
Answer: AND gate
Q.19. The output of a gate is LOW when at least one of its inputs is HIGH. This is true for
- AND
- NAND
- NOR
- OR
Answer: NOR
Q.20. The output of a gate is HIGH when at least one of its inputs is LOW. It is true for
- X-OR
- NAND
- NOR
- OR
Answer: NAND
Q.21. The output of a gate is LOW if and only if all its inputs are HIGH. It is true for
- AND
- X-NOR
- NOR
- NAND
Answer: NAND
Q.22. The output of a gate is HIGH if and only if all its inputs are LOW. It is true for
- NOR
- X-OR
- NAND
- X-NOR
Answer: NOR
Q.23. The most suitable gate for comparing two bits is
- AND
- OR
- NAND
- X-OR
Answer: X-OR
Q.24. Which of the following gates cannot be used as an inverter?
- NAND
- AND
- NOR
- X-NOR
Answer: AND
Q.25. A gate is enabled when its enable input is at logic 1. The gate is
- OR
- NAND
- NOR
- none of these
Answer: NAND
Q.26. A gate is enabled when its enable input is at logic 0. The gate is
- NOR
- AND
- NAND
- none of these
Answer: NOR
Q.27. A gate is inhibited when its inhibit input is at logic 1. The gate is
- AND
- NAND
- OR
- none of these
Answer: OR
Q.28. A gate is disabled when its disable input is at logic 0. The gate is
- AND
- NOR
- OR
- None of these
Answer: AND
Q.29. The output of a logic gate is 1 when all its inputs are at logic 1. The gate is either
- a NAND or a NOR
- an AND or an OR
- an OR or an X-OR
- an AND or a NOR
Answer: an AND or an OR
Q.30. The output of a logic gate is 1 when all its inputs are at logic 0. The gate is either
- a NAND or a NOR
- an AND or an X-NOR
- an OR or a NAND
- an X-OR or an X-NOR
Answer: a NAND or a NOR
Q.31. The output of a logic gate is 1 when all its inputs are at logic 1. The gate is either
- an OR or an X-OR
- a NAND or an X-NOR
- an AND or a NAND
- an OR or an X-NOR
Answer: an OR or an X-NOR
Q.32. The output of a logic gate is 1 when all its inputs are at logic 0. The gate is either
- a NOR or an X-NOR
- a NAND or an X-OR
- an OR or an X-NOR
- an AND or an X-OR
Answer: a NOR or an X-NOR
Q.33. The output of a logic gate is 0 when all its inputs are at logic 1. The gate is either
- a NAND or an AND
- a NAND or an X-OR
- a NOR or an X-NOR
- a NAND or an X-NOR
Answer: a NAND or an AND
Q.34. The output of a logic gate is 0 when all its inputs are at logic 0. The gate is either
- an AND or a NOR
- a NAND or an X-OR
- an OR or an X-OR
- an OR or an X-NOR
Answer: an OR or an X-OR
Q.35. The number of rows in the truth table of a 4-input gate is
- 4
- 8
- 12
- 16
Answer: 16
Q.36. Which of the following statements is true?
- OR and NOT gates are necessary and sufficient for realization of any logic function.
- AND and NOT gates are necessary and sufficient for realization of any logic function.
- NAND gates are not sufficient to realize any logic function.
- NOR gates are sufficient to realize any logic function.
Answer: NOR gates are sufficient to realize any logic function.