Q 12-14-082JEE MainJEE Main 2023 (30 Jan, Shift 1)Medium
The output waveform of the given logical circuit for the following inputs $A$ and $B$ as shown below, is
Answer: (D) see figure
A NAND gate with its inputs joined is a NOT gate, so the first two gates give $\bar A$ and $\bar B$. The last NAND gives
$$Y=\overline{\bar A\cdot\bar B}=A+B\quad\text{(OR)}$$
$Y=1$ whenever either input is high: from $t_1$ to $t_4$ ($A$ then $B$ high), $0$ from $t_4$ to $t_5$, and $1$ after $t_5$ ($A$ high until $t_6$, then $B$ high). This is waveform (4).
Solution by Sreeraj P, M.Sc Physics