JEE Main · 2021 · 26 Aug 2021 · Shift 1 · Semiconductors

Identify the logic operation carried out by the given circuit :-

Answer: (B)

Solution

Each input first meets an inverter, so the two intermediate lines carry

X = \overset{ˉ}{A}

and

Y = \overset{ˉ}{B}

, and these feed the AND gate that follows:

Z = \overset{ˉ}{A} \cdot \overset{ˉ}{B}

By De Morgan's theorem

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

, so the output is

1

only when both inputs are

0

and is

0

otherwise. The circuit performs the NOR operation.

JEE Main · 2021 · 26 Aug 2021 · Shift 1 · Single correct option