Identify the gates G1 and G2 respectively in the figure given below to get Y = ABC

This question was previously asked in

ISRO (VSSC) Technical Assistant Electronics 2019 Official Paper

Option 1 : NOR & AND

ISRO VSSC Technical Assistant Mechanical held on 09/06/2019

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80 Questions
320 Marks
120 Mins

To get Y = ABC, we have to eliminate the complement of A̅ and B̅ from the input of the gate G_{1}.

This is possible with either a NAND gate at G_{1} or a NOR gate at G_{1}

With NAND at G_{1} and OR at G_{2}, we get:

\(Y = \overline {\left( {\bar A\;\bar B} \right)} + C\)

Y = A + B + C

∴ This is not the required case.

With NOR at G_{1} and AND at G_{2}, we get:

\(Y = \overline {\left( {\bar A + \bar B} \right)} \cdot \left( C \right)\)

\(Y = \overline {\bar A} \cdot \overline {\bar B} \cdot C\) (Using De-Morgan’s law)

Y = ABC