Topic: Digital Circuits
For the switch circuit, taking open as 0 and closed as 1, the expression for the circuit in Y (A in series with parallel combination of (B in series with C) and D)
- A. A + (B + C)D
- B. A + BC + D
- C. A(BC + D)
- D. None of these
Answer: C. A(BC + D)
Explanation: Switches in series correspond to an AND operation (multiplication), and switches in parallel correspond to an OR operation (addition). Switches B and C are in series (B * C), and they are in parallel with D (BC + D). This entire block is in series with A, yielding A * (BC + D).