# Combinational Circuit

 Question 1
A Boolean digital circuit is composed using two 4-input multiplexers (M1 and M2) and one 2-input multiplexer (M3) as shown in the figure. X0-X7 are the inputs of the multiplexers M1 and M2 and could be connected to either 0 or 1. The select lines of the multiplexers are connected to Boolean variables A, B and C as shown.

Which one of the following set of values of (X0, X1, X2, X3, X4, X5, X6, X7) will realise the Boolean function $\bar{A}+\bar{A}\cdot \bar{C}+A\cdot \bar{B}\cdot C$ ?
 A (1, 1, 0, 0, 1, 1, 1, 0) B (1, 1, 0, 0, 1, 1, 0, 1) C (1, 1, 0, 1, 1, 1, 0, 0) D (0, 0, 1, 1, 0, 1, 1, 1)
GATE CSE 2023   Digital Logic
Question 1 Explanation:
 Question 2
The output of a 2-input multiplexer is connected back to one of its inputs as shown in the figure.

Match the functional equivalence of this circuit to one of the following options.
 A D Flip-flop B D Latch C Half-adder D Demultiplexer
GATE CSE 2023   Digital Logic
Question 2 Explanation:

 Question 3
Which one of the following circuits implements the Boolean function given below?

$f(x,y,z) = m_0+m_1+m_3+m_4+m_5+m_6$

where $m_i$ is the $i^{th}$ minterm.

 A A B B C C D D
GATE CSE 2021 SET-2   Digital Logic
Question 3 Explanation:
 Question 4
Consider the following circuit

The function by the network above is
 A $\overline{A B} E+E F+\overline{C D} F$ B $(\bar{E}+A B \bar{F})(C+D+\bar{F})$ C $(\overline{A B}+E)(\bar{E}+\bar{F})(C+D+\bar{F})$ D $(A+B) \bar{E}+\overline{E F}+C D \bar{F}$
ISRO CSE 2020   Digital Logic
Question 4 Explanation:
 Question 5
Following Multiplexer circuit is equivalent to

 A Sum equation of full adder B Carry equation of full adder C Borrow equation for full subtractor D Difference equation of a full subtractor
ISRO CSE 2020   Digital Logic
Question 5 Explanation:

There are 5 questions to complete.

### 5 thoughts on “Combinational Circuit”

1. Question number 37, correct answer is option A. Please update it.

We have updated the option.