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The given circuit is equivalent to:

Asked in NEET 2023 (mpr) · Gate combinations and truth tables

Figure: Gate combinations and truth tables

(1) a NOR gate
(2) a NAND gate
(3) an OR gate
(4) an AND gate

Answer: (4) an AND gate

Step-by-step solution

Idea: push the inverters through the final gate with De Morgan's law.

The inverters deliver A and B to the NOR.

Y=A+B.

De Morgan turns the complement of a sum into a product of complements: A+B=A· B.

The circuit is an AND gate.

Why the other options are wrong

(1) comes from a NOR is the last gate by itself; feeding it the complements of A and B instead of A and B changes what the whole circuit does.
(2) comes from a NAND is low only for A=B=1, whereas this circuit is high only then.
(3) comes from an OR is high whenever either input is high; with A=1,B=0 this circuit gives 0+1=0.

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