Question

Identify the logic operation carried out by the following circuit.

• A. NAND
• B. OR
• C. NOR
• D. AND

Answer 1

The correct option is D AND

Truth table of the given circuit is as follows.

A	B	$\overline{A}$	$\overline{B}$	$Y=\overline{\overline{A}.\overline{B}}$
0	0	1	1	0
0	1	1	0	0
1	0	0	1	0
1	1	0	0	1

$\Rightarrow$ The given circuit is equivalent to AND gate.

Alternate method:

The output $Y=\overline{\overline{A}.\overline{B}}$
According to Morgan's law

$Y=\overline{\overline{A}.\overline{B}}=\overline{A}+\overline{B}=A.B$

So, the given circuit is equivalent to AND gate.

Hence, $\left(D\right)$ is the correct answer.