GATE Analog and Digital Electronics: Combinational Logic – Previous Year Questions

2 GATE previous year questions on Combinational Logic (Analog and Digital Electronics, Biomedical Engineering) with answers and explanations, from every paper.

1. GATE 2021 BM Q16 (1 mark, Multiple choice) – Y=Y₁Y₀ is the two-bit output of the combinational circuit shown. What is the maximum value of Y for digital inputs A₁A₀ and B₁B₀?
2. GATE 2022 BM Q17 (1 mark, Multiple choice) – Input bits X and Y are added by the combinational logic shown. S is their sum bit. For correct operation, what are D₀,D₁,D₂,D₃ in that order?