# Multiple Choice Questions with Answers on Digital Electronics Circuits - Logic Gates & Boolean Expression Simplification

1. A/ . B/ . C/ = D represents a

a)   NOR gate

b)   AND gate

c)   NAND gate

d)   EX-OR gate

Ans: a

2. Output of which of the following gates is 0 only if at least one of its inputs is 1?

a)   NOR gate

b)   AND gate

c)   NAND gate

d)   EX-OR gate

Ans: a

3. Which of the following gates are added to the input of the OR gate to convert it into NAND gate?

a)   NOT gate

b)   AND gate

c)   OR gate

d)   EX-OR gate

Ans: a

4. Which logic function is produced by adding inverters to the inputs of an AND gate?

a)   NOR gate

b)   OR gate

c)   NAND gate

d)   EX-OR gate

Ans: a

5. Which logic function is produced by adding inverters to each input and the output of an AND gate?

a)   NOR gate

b)   OR gate

c)   NAND gate

d)   EX-OR gate

Ans: b

6. What is the reduced form of (A+B) (A+C)?

a)   AB + AC

b)   A+B+C

c)   AC + B

d)   A + BC

Ans: d

7. Which of the following is the reduced form of A/ B/ + AB/ + AB?

a)   A + B/

b)   A/  + B

c)   A

d)   A + B

Ans: a

8. Which of the following is the simplified form of Boolean expression (A + B + AB) (A + C)?

a)   A + B + C

b)   AB + BC

c)   A + BC

d)   AC + B

Ans: c

9. Which of the following is the simplified form of Boolean Expression (A + B/ + C) (A + B/ + C/) (A + B + C)?

a)   A/  B + C/

b)   A + B/ C

c)   A

d)   AB + C/

Ans: b

10. Which of the following is the complement of Boolean Expression A (B + C) (C/ + D/)?

a)   A/ + B/ C/ + CD

b)   A + BC + C/ D/

c)   A (B + C) (C + D)

d)   (C/ + D/) (B + A) CA

Ans: a

Hope this post on "MCQ on Digital Electronics with Answers - 4" will help Electronics Engineering and Electrical Engineering students in preparation of technical interviews, GATE, IES etc.