JEE Main · 2021 · 31 Aug 2021 · Shift 1 · Semiconductors

In the following logic circuit the sequence of the inputs

A, B

are

(0, 0), (0, 1), (1, 0)

and

(1, 1)

. The output Y for this sequence will be :

Answer: (B)

Solution

The upper gate forms

P = A \cdot B

and the lower gate forms

Q = A + B

; the final gate gives

Y = \overline{P \cdot Q}

. Because

A \cdot B

being true already forces

A + B

true,

P \cdot Q = A \cdot B

, so

Y = \overline{A \cdot B}

. For the inputs

(0, 0), (0, 1), (1, 0), (1, 1)

this yields

Y = 1, 1, 1, 0

JEE Main · 2021 · 31 Aug 2021 · Shift 1 · Single correct option