Topic: Digital Circuits
The circuit is formed as shown below. The output S and C implement (Logic diagram with inputs A, B, two NOT gates, two AND gates, and an OR gate)
- A. Two bit adder with sum and carry respectively
- B. Two bit subtractor with sum and borrow respectively
- C. $S = \overline{A}B + A\overline{B}; C = \overline{A}B$
- D. None of the above
Answer: C. $S = \overline{A}B + A\overline{B}; C = \overline{A}B$
Explanation: The logic circuit evaluates to $S = A\overline{B} + \overline{A}B$ (which is the XOR operation for the difference) and $C = \overline{A}B$ (which is the borrow operation). This logic specifically implements a half subtractor, and the exact boolean expressions for it correspond to option (c).