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 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 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 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 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


There are 5 questions to complete.

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