Digital Logic · Combinational and Sequential Circuits
Official IIT answer key · IIT Kanpur · Audited Aug 2026
GATE CSE 2023 Q44 · MCQ · 2 marks
A Boolean digital circuit is composed using two 4-input multiplexers (M1 and M2) and one 2-input multiplexer (M3) as shown in the figure. X0–X7 are the inputs of the multiplexers M1 and M2 and could be connected to either 0 or 1. The select lines of the multiplexers are connected to Boolean variables A, B and C as shown.
Key concept
Topic notes
GATE extensively tests combinational and sequential circuit design through both analytical tracing and formal synthesis. In combinational circuits, questions focus on multiplexer tree implementations, decoder-to-memory interfacing, and Boolean function realization using universal MUX/decoder blocks. In sequential logic, the focus is on synchronous counter state tracing, excitation equation derivation (for D, T, and JK flip-flops), non-standard sequence flip-flop counting, ripple counter frequency division, and FSM equivalence minimization.
Full Combinational and Sequential Circuits guide →Independent practice explanation verified by the GateAI team. GATE is conducted by the IITs; question text follows the official paper.
