Semiconductor Electronics question for JEE Main (JEE Main 2020 (8 Jan, Shift 2)), with solution

Answer: (A) $0$

Follow the signals:

The NOT gate turns input $1$ into $0$. This $0$ goes to both inputs of the top NAND gate, so its output is $\overline{0\cdot0} = 1$.

The same $0$ passes through the second NOT gate, giving $1$ at the upper input of the middle NAND gate.

The bottom NAND gate has inputs $0$ and $1$ (the top gate's output), so its output is $\overline{0\cdot1} = 1$.

The middle NAND gate has inputs $1$ and $1$, so $Y = \overline{1\cdot1} = 0$.

Solution by Sreeraj P, M.Sc Physics