Question

Input waveforms A and B as shown in figure-I are applied· to the combination of gates shown in figure-II. Which of the following waveforms shown in figures (i) to (iv) correctly represents the output waveform?

• A. Figure (i)
• B. Figure (ii)
• C. Figure (iii)
• D. Figure (iv)

Answer 1

Answer: (C)

The boolean expression of this arrangement is ,
For $NOT$ gate
$Y_{1}=\bar{A}$ , $Y_{2}=\bar{B}$
For $OR$ gate
$Y=Y_{1}+Y_{2}$
$Y=\bar{A}+\bar{B}$
$Y=\bar{A \cdot B}$
Truth Table

1

Hence, it is clear that option $3$ are correct.