# Logic gates MCQ SET-3

Logic Gates MCQ Set-3 Question with Answer

1. A gate is enabled when its enable input is at logic 0. The gate is

Answer : (A) NOR

2. A gate is inhibited when its inhibit input is at logic 1. The gate is

Answer : (C) OR

3. A gate is disabled when its disable input is at logic 0. The gate is

Answer : (A) AND

4. The output of a logic gate is 1 when all its inputs are at logic 1. The gate is either

Answer : (B) An AND or an OR

5. The output of a logic gate is 1 when all its inputs are at logic 0. The gate is either

Answer : (A) A NAND or a NOR

##### Logic Gates MCQ

6. The Output of a logic gate is 1 when all its inputs are at logic 1. The gate is either

Answer : (D) An OR or an X-NOR

7. The output of a logic gate is 1 when all its inputs are at logic 0. The gate is either

Answer : (A) A NOR or an X-NOR

8. The output of a logic gate is 0 when all its inputs are at logic 1. the gate is either

Answer : (A) A NOR or an X-NOR

9. The output of a logic gate is 0 when all its inputs are at logic 0. the gate is either

Answer : (C) An OR or an X-OR

10. The number of rows in the truth table of a 4-input gate is

Answer : (D) 16

##### Logic Gates MCQ

11. Which of the following statements is true?

Answer : (A) OR and NOT gates are necessary and sufficient for realization of any logic function.

12. For checking the parity of a digital word, it is perferable to use

Answer : (C) X-OR gates

13. The most suitable gate to check whether the number of 1s in a digital word is even or odd is

Answer : (A) X-OR

14. Which of the following operations is commutative but not associative?

Answer : (D) NAND

15. Which of the following operations is commutaive but not associative?

Answer : (B) NOR

##### Logic Gates MCQ

16. How many minimum NOR gates is rwquired to implement NAND gate?

Answer : (A) 3

17. The minimum number of NAND required to implement an EX-OR gate is

Answer : (C) 4

18. The Number of XOR gates required for conversion of 11011 to is equivalent Gray code is

Answer : (D) 4

19. The gates required to build a half adder are

Answer : (C) EX-OR gate and AND gate

20. Which of the following is an Universal gate?

Answer : (C) NOR