This set of Digital Circuits Multiple Choice Questions & Answers (MCQs) focuses on “Half Adder & Full Adder”.

1. Total number of inputs in a half adder is __________

a) 2

b) 3

c) 4

d) 1

2. In which operation carry is obtained?

a) Subtraction

b) Addition

c) Multiplication

d) Both addition and subtraction

3. In parts of the processor, adders are used to calculate ____________

a) Addresses

b) Table indices

c) Increment and decrement operators

d) All of the Mentioned

4. If A and B are the inputs of a half adder, the sum is given by __________

a) A AND B

b) A OR B

c) A XOR B

d) A EX-NOR B

5. Half-adders have a major limitation in that they cannot __________

a) Accept a carry bit from a present stage

b) Accept a carry bit from a next stage

c) Accept a carry bit from a previous stage

d) Accept a carry bit from the following stages

6. If A, B and C are the inputs of a full adder then the sum is given by __________

a) A AND B AND C

b) A OR B AND C

c) A XOR B XOR C

d) A OR B OR C

7. If A and B are the inputs of a half adder, the carry is given by __________

a) A AND B

b) A OR B

c) A XOR B

d) A EX-NOR B

8. The difference between half adder and full adder is __________

a) Half adder has two inputs while full adder has four inputs

b) Half adder has one output while full adder has two outputs

c) Half adder has two inputs while full adder has three inputs

d) All of the Mentioned

9. If A, B and C are the inputs of a full adder then the carry is given by __________

a) A AND B OR (A OR B) AND C

b) A OR B OR (A AND B) C

c) (A AND B) OR (A AND B)C

d) A XOR B XOR (A XOR B) AND C

10. How many AND, OR and EXOR gates are required for the configuration of full adder?

a) 1, 2, 2

b) 2, 1, 2

c) 3, 1, 2

d) 4, 0, 1