Logic Gates question from MHT CET 2024 (4 May, Shift 2)

Answer: (a)

1. Upper gate is NOR: $\overline{A + B}$. Lower gate is AND: $A \cdot B$. Final gate is NAND.
2. $Y = \overline{\overline{A + B} \cdot (A \cdot B)}$.
3. $\overline{A + B}$ and $A \cdot B$ can never both be 1, so their product is always 0 and $Y = 1$ for all inputs.
4. Table P has Y = 1 in every row, so the answer is (a) P.