Question

Identify the correct output signal \( Y \) in the given combination of gates for the given inputs \( A \) and \( B \) shown in the figure. 
 

• A.
• B.
• C.
• D.

Hint:

De-Morgan’s Theorem is a useful tool to simplify Boolean expressions: \( \overline{A \cdot B} = \overline{A} + \overline{B} \) and \( \overline{A + B} = \overline{A} \cdot \overline{B} \).

Answer 1

The Correct Option is D

Step 1: {Logic Circuit Analysis}
The circuit comprises NOT gates applied to inputs \( A \) and \( B \), followed by an AND gate processing these inverted signals.
Step 2: {Boolean Expression Derivation}
The circuit represents the expression: \[ Y = \overline{A} \cdot \overline{B} \] Using De-Morgan’s theorem, this simplifies to: \[ Y = \overline{(A + B)} \] 
Step 3: {Waveform Comparison and Conclusion}
Comparison with the truth table indicates that waveform 4 corresponds to the derived output. Therefore, the correct answer is (D).