Q199 / 200 · MHT CET - Medical 2026 (24 April Shift 2) · Physics
The output of the logic circuit shown in figure will be
- A$X = \overline{A.B}$
- Correct answerB$X = A.B$
- C$X = \overline{A + B}$
- D$X = A + B$
Solution
The given logic circuit consists of two NAND gates.
The output of the first NAND gate with inputs $A$ and $B$ is:
$Y = \overline{A \cdot B}$
This output $Y$ is connected to both inputs of the second NAND gate. A NAND gate with its inputs tied together acts as a NOT gate.
The final output $X$ is:
$X = \overline{Y \cdot Y} = \overline{Y}$
Substituting the value of $Y$:
$X = \overline{\overline{A \cdot B}} = A \cdot B$
Thus, the circuit acts as an AND gate.
Answer: $X = A.B$
The output of the first NAND gate with inputs $A$ and $B$ is:
$Y = \overline{A \cdot B}$
This output $Y$ is connected to both inputs of the second NAND gate. A NAND gate with its inputs tied together acts as a NOT gate.
The final output $X$ is:
$X = \overline{Y \cdot Y} = \overline{Y}$
Substituting the value of $Y$:
$X = \overline{\overline{A \cdot B}} = A \cdot B$
Thus, the circuit acts as an AND gate.
Answer: $X = A.B$
Hence, the correct answer is option: 'B'.