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GATE 2014 EC (EC4) – Question 50

Digital Circuits · Combinatorial Circuits · 2 marks · Multiple choice

Find Y implemented by the 8-to-1 multiplexer shown.

Diagram for GATE 2014 EC (EC4) question 50
  1. $A\overline BC+A\overline CD$
  2. $\overline ABC+A\overline BD$
  3. $AB\overline C+\overline ACD$
  4. $\overline A\overline BD+A\overline BC$

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Correct answer: (C) $AB\overline C+\overline ACD$

Explanation

Selectors are A,B,C. Inputs I1and I3equal D, contributing ĀB̄CD+ĀBCD=ĀCD. Input I6is1, contributing ABC̄; all other inputs are0. Therefore **Y=ABC̄+ĀCD,C**. D is a data variable, not one of the three select bits.