JEE Main · 2021 · 17 Mar 2021 · Shift 1 · Semiconductors

The output of the given combination gates represents:

Answer: (B)

Solution

Every gate in the chain is a NOR gate. The first two have both inputs tied to a single line, so they act as inverters and deliver

\overset{ˉ}{A}

and

\overset{ˉ}{B}

. Feeding these into the third NOR gate gives

Y_{1} = \overline{\overset{ˉ}{A} + \overset{ˉ}{B}} = A \cdot B

The last gate again has its inputs tied together, so it inverts this result:

Y = \overline{A \cdot B}

The combination therefore behaves as a NAND gate.

JEE Main · 2021 · 17 Mar 2021 · Shift 1 · Single correct option