Identify the logic operation carried out by the given circuit :-

Solution

Physics sir · 3 steps

Each NAND with its inputs tied together is only a NOT gate, so you are ANDing Ā and B̄.

1. Tied NAND is NOT. Both inputs of each NAND gate are joined, so the gate sees the same signal twice. A · A̅ = Ā, so X = Ā and, in the same way, Y = B̄.
2. Final AND gate. The last gate ANDs these two inverted signals. De Morgan's theorem then turns the product of the complements into the complement of a sum.

   Z = Ā·B̄ = A + B̅

   A	B	X = Ā	Y = B̄	Z = X · Y
   0	0	1	1	1
   0	1	1	0	0
   1	0	0	1	0
   1	1	0	0	0

3. So. The output is 1 only when both inputs are 0. That is the truth table of a NOR gate, option (c).

The idea to keep. A NAND or NOR with its inputs shorted together is just a NOT gate. Inverting the inputs of an AND gives NOR, and inverting the inputs of an OR gives NAND.

Answer from the NTA final answer key. Solution by PrepWiser.