MCQ on Digital Electronics with Answers - 8

Multiple Choice Questions with Answers on Digital Electronics Circuits - Combinational Logic Circuits

1. 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

Ans: c)

 

2. 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

Ans: c)

 

3. 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

Ans: b)

 

4. How many outputs are required for the implementation of a subtractor?
    a) 1
    b) 2
    c) 3
    d) 4

Ans: b)

 

5. Let A and B is the input of a subtractor then the output will be
    a) A XOR B
    b) A AND B
    c) A OR B
    d) A EXNOR B

Ans: a)

 

6. Let A and B is the input of a subtractor then the borrow will be
    a) A AND B^/
    b) A’ AND B
    c) A OR B
    d) A AND B

Ans: b)

 

7. The full subtractor can be implemented using
    a) Two XOR and an OR gates
    b) Two half subtractors and an OR gate
    c) Two multiplexers and an AND gate

    d) Two comparators and an AND gate

Ans: b)

 

8. In a combinational circuit, the output at any time depends only on the _______ at that time.
    a) Voltage
    b) Intermediate values
    c) Input values
    d) Clock pulses

Ans: c)

 

9. In a sequential circuit, the output at any time depends on
    a) Past output values
    b) Intermediate values
    c) Both past output and present input
    d) Present input values

Ans: c)

 

10. The design of an ALU is based on
    a) Sequential logic
    b) Combinational logic
    c) Multiplexing
    d) De-Multiplexing

Ans: b)

Hope this post on "MCQ on Digital Electronics with Answers - 8" will help Electronics Engineering and Electrical Engineering students in preparation of technical interviews, GATE, IES etc.